Rectangle 27 4

For me it works better to check the Primefaces showcase first, then later one can always refer to the manual.

According to the example "Programmatic menu" you need the part

<p:growl id="messages" showDetail="false"/>

I guess thats also in fact what the error message is stating, that its missing.

About the annotations see the recommendation i.e. here. Since JSF 2.2 it is recommended to move from JSF beans to CDI beans.

jsf - Primefaces 5 - Dynamic p:menu issues - Stack Overflow

jsf jsf-2 primefaces menu managed-bean
Rectangle 27 2

Cannot find component with expression "messages" referenced from "j_idt5:j_idt6"

another solution is to remove item.setUpdate("messages"); if you dont want to update anything, or you add a component with id message in you page if you want to update the message.

jsf - Primefaces 5 - Dynamic p:menu issues - Stack Overflow

jsf jsf-2 primefaces menu managed-bean
Rectangle 27 17

The trigger attribute binds jQuery listeners on the specified elements. However if you update an element the binding gets lost. I don't know if it works, but you could try moving the <p:blockUI inside the resultsPanel. I suspect that when you update the panel the blockUI gets updated too and thus re-binding the listener to the data table.

<p:panel header="Results Grid" id="resultsPanel">
    ...
    <p:dataTable ... id="VAResults" ... >
        ...
    </p:dataTable>
    ....
    <p:blockUI block="resultsPanel" trigger="submitButton, resetScenarioButton, VAResults">
    Loading...
</p:blockUI>
</p:panel>

i had same problem but your answer solved it.. i had put blockui outside the form and thats why i got a problem well thanks man (Y)

jsf 2 - Primefaces blockUI stops working after ajax update - Stack Ove...

ajax jsf-2 primefaces blockui
Rectangle 27 16

The trigger attribute binds jQuery listeners on the specified elements. However if you update an element the binding gets lost. I don't know if it works, but you could try moving the <p:blockUI inside the resultsPanel. I suspect that when you update the panel the blockUI gets updated too and thus re-binding the listener to the data table.

<p:panel header="Results Grid" id="resultsPanel">
    ...
    <p:dataTable ... id="VAResults" ... >
        ...
    </p:dataTable>
    ....
    <p:blockUI block="resultsPanel" trigger="submitButton, resetScenarioButton, VAResults">
    Loading...
</p:blockUI>
</p:panel>

i had same problem but your answer solved it.. i had put blockui outside the form and thats why i got a problem well thanks man (Y)

jsf 2 - Primefaces blockUI stops working after ajax update - Stack Ove...

ajax jsf-2 primefaces blockui
Rectangle 27 1

After reading the Primefaces 5 documentation, what I did was to invoke (in the Create.xhtml) the Primefaces filter method, referencing through the widgetVar defined in the target datatable (in List.xhtml). Doing so, it triggers my p:remoteCommand, which in its turn, triggers the update for the summary row:

<p:commandButton actionListener="#{treinamentosController.saveNew}" value="#{treinaBundle.Save}" update="@this,display,:TreinamentosListForm:datalist,:growl" oncomplete="handleSubmit(xhr,status,args,PF('TreinamentosCreateDialog'),PF('treinamentosTable').filter());" >
    <p:confirm header="#{treinaBundle.ConfirmationHeader}" message="#{treinaBundle.ConfirmCreateMessage}" icon="ui-icon-alert"/>
</p:commandButton>

If someone has a more elegant solution, please share. I had not time

jsf - Updating Primefaces datatable summary row using Ajax - Stack Ove...

ajax jsf primefaces datatable
Rectangle 27 34

The onclick is executed before the ajax request. You need to open the dialog in oncomplete instead. This will be executed after the ajax request and update. The <p:dialog> is namely by default hidden unless its visible attribute evaluates true.

Unrelated to the concrete problem, are you aware that you can pass fullworthy objects as method arguments since EL 2.2? This makes the <f:attribute> and actionListener "hack" superfluous:

<p:commandLink value="Read more" action="#{content.getFullArticle(news)}" 
    update=":dialog" oncomplete="dlg.show()" />

I'm running on tomcat 6 and that doesn't support the EL 2.2 does it?

server guys won't buy that one here. I'll have to stick with attribute/actionlistener. Thanks for the advice though.

Bummer then. Even not when just in webapp's own /WEB-INF/lib? Anyway, no problem and you're welcome :)

update=":dialog"
update="dialog"

jsf - Primefaces how to update content in a dialog and keep the dialog...

jsf jsf-2 primefaces
Rectangle 27 34

The onclick is executed before the ajax request. You need to open the dialog in oncomplete instead. This will be executed after the ajax request and update. The <p:dialog> is namely by default hidden unless its visible attribute evaluates true.

Unrelated to the concrete problem, are you aware that you can pass fullworthy objects as method arguments since EL 2.2? This makes the <f:attribute> and actionListener "hack" superfluous:

<p:commandLink value="Read more" action="#{content.getFullArticle(news)}" 
    update=":dialog" oncomplete="dlg.show()" />

I'm running on tomcat 6 and that doesn't support the EL 2.2 does it?

server guys won't buy that one here. I'll have to stick with attribute/actionlistener. Thanks for the advice though.

Bummer then. Even not when just in webapp's own /WEB-INF/lib? Anyway, no problem and you're welcome :)

update=":dialog"
update="dialog"

jsf - Primefaces how to update content in a dialog and keep the dialog...

jsf jsf-2 primefaces
Rectangle 27 31

onclick is called before the ajax request is even created (pure client side) while oncomplete and onsuccess are executed after the server responded to the ajax request. So, if you need to execute some business logic before showing a dialog, for example, you want to go with oncomplete. That's what I always use.

You can also condition your javascript inside oncomplete to perform only if there's no validation errors. Intuitively I think onsuccess would behave like that and only execute when there's no validation errors, but that's not how it goes. I don't really know the difference between them. I assume there's a way to flag success=false in the backing beans, but I couldn't really find it in the documentation.

If you want to check for validation in your oncomplete attribute, this is how you'd do:

oncomplete="if (!args.validationFailed){someDialog.hide()}"

In this case, you would only close the dialog if the fields are properly validated. You can actually inject parameters from the backing bean and use them in the javascript after the request has been served. In your backing bean you can do something like this:

RequestContext.getCurrentInstance().addCallbackParam("showDialog", false);

And you can access the parameter like this in your incomplete attribute:

oncomplete="if (args &amp;&amp; args.showDialog){someDialog.show()}else{ alert('the bean didnt let me open the dialog')}"

I needed to escape tha & symbols: oncomplete="if (args args.showDialog){ dialog1.show() }else{ alert('the bean didnt let me open the dialog')}"

jsf - Primefaces onclick and onsuccess differences - Stack Overflow

jsf primefaces
Rectangle 27 31

onclick is called before the ajax request is even created (pure client side) while oncomplete and onsuccess are executed after the server responded to the ajax request. So, if you need to execute some business logic before showing a dialog, for example, you want to go with oncomplete. That's what I always use.

You can also condition your javascript inside oncomplete to perform only if there's no validation errors. Intuitively I think onsuccess would behave like that and only execute when there's no validation errors, but that's not how it goes. I don't really know the difference between them. I assume there's a way to flag success=false in the backing beans, but I couldn't really find it in the documentation.

If you want to check for validation in your oncomplete attribute, this is how you'd do:

oncomplete="if (!args.validationFailed){someDialog.hide()}"

In this case, you would only close the dialog if the fields are properly validated. You can actually inject parameters from the backing bean and use them in the javascript after the request has been served. In your backing bean you can do something like this:

RequestContext.getCurrentInstance().addCallbackParam("showDialog", false);

And you can access the parameter like this in your incomplete attribute:

oncomplete="if (args &amp;&amp; args.showDialog){someDialog.show()}else{ alert('the bean didnt let me open the dialog')}"

I needed to escape tha & symbols: oncomplete="if (args args.showDialog){ dialog1.show() }else{ alert('the bean didnt let me open the dialog')}"

jsf - Primefaces onclick and onsuccess differences - Stack Overflow

jsf primefaces
Rectangle 27 26

Try to inspect the generated HTML code and see the actual id being generated for your panelGrid and update that id. If it happens to be dynamic, you can always use the JQuery CSS selectors (I find myself doing that pretty often). In your case, you can go like this:

update="@([id$=output])"

This expression stands for every component whose id ends with output. Take a look at the JQuery docs for more info.

I used this trick in item.setUpdate, many thanks!

I had a similar problem, and this solution worked perfectly. I was not so lucky with the other one, using p:component.

I had a similar problem and this worked like a charm. However, i think this is getting deprecated with primefaces...

jsf - Primefaces - Cannot find component with identifier outside the d...

jsf primefaces
Rectangle 27 9

You need to reload the users from the DB after deletion.

userService.removeUserById(id);
users = userService.list();

Thank you very much. I don't know why I forgot that. Reloading the list works great!

jsf - Primefaces - update datatable with commandButton doesn't work - ...

jsf primefaces datatable ajax-update
Rectangle 27 5

You can't (PrimeFaces 3.5) directly bind datatable filters with JSF bean, so they will not be preserved when you update the whole component.

But if you call filter() on datatable widget, the data will be reloaded from server, without re-rendering the whole datatable component (so the filters will be preserved)

<p:dataTable .... widgetVar="myTable"> ...</p:dataTable>

<p:commandButton action="#{myBean.doSth}" .... oncomplete="myTable.filter()"/>

Thanks, I can confirm that this works.

jsf 2 - Primefaces Datatable lost text in Filter field after datatable...

jsf-2 primefaces
Rectangle 27 214

The process attribute is server side and can only affect UIComponents implementing EditableValueHolder (input fields) or ActionSource (command fields). The process attribute tells JSF, using a space-separated list of client IDs, which components exactly must be processed through the entire JSF lifecycle upon (partial) form submit.

JSF will then apply the request values (finding HTTP request parameter based on component's own client ID and then either setting it as submitted value in case of EditableValueHolder components or queueing a new ActionEvent in case of ActionSource components), perform conversion, validation and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false during apply request values phase will also be skipped as part of safeguard against tampered requests.

Note that it's in case of ActionSource components (such as <p:commandButton>) very important that you also include the component itself in the process attribute, particularly if you intend to invoke the action associated with the component. So the below example which intends to process only certain input component(s) when a certain command component is invoked ain't gonna work:

It would only process the #{bean.foo} and not the #{bean.action}. You'd need to include the command component itself as well:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="@this foo" action="#{bean.action}" />

Or, as you apparently found out, using @parent if they happen to be the only components having a common parent:

<p:panel><!-- Type doesn't matter, as long as it's a common parent. -->
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@parent" action="#{bean.action}" />
</p:panel>

Or, if they both happen to be the only components of the parent UIForm component, then you can also use @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@form" action="#{bean.action}" />
</h:form>

This is sometimes undesirable if the form contains more input components which you'd like to skip in processing, more than often in cases when you'd like to update another input component(s) or some UI section based on the current input component in an ajax listener method. You namely don't want that validation errors on other input components are preventing the ajax listener method from being executed.

Then there's the @all. This has no special effect in process attribute, but only in update attribute. A process="@all" behaves exactly the same as process="@form". HTML doesn't support submitting multiple forms at once anyway.

There's by the way also a @none which may be useful in case you absolutely don't need to process anything, but only want to update some specific parts via update, particularly those sections whose content doesn't depend on submitted values or action listeners.

The update attribute is client side and can affect the HTML representation of all UIComponents. The update attribute tells JavaScript (the one responsible for handling the ajax request/response), using a space-separated list of client IDs, which parts in the HTML DOM tree need to be updated as response to the form submit.

JSF will then prepare the right ajax response for that, containing only the requested parts to update. JSF will skip all other components which are not covered by update attribute in the ajax response, hereby keeping the response payload small. Also, components whose rendered attribute evaluates to false during render response phase will be skipped. Note that even though it would return true, JavaScript cannot update it in the HTML DOM tree if it was initially false. You'd need to wrap it or update its parent instead. See also Ajax update/render does not work on a component which has rendered attribute.

Usually, you'd like to update only the components which really need to be "refreshed" in the client side upon (partial) form submit. The example below updates the entire parent form via @form:

process
@form

Whilst that may work fine, the update of input and command components is in this particular example unnecessary. Unless you change the model values foo and bar inside action method (which would in turn be unintuitive in UX perspective), there's no point of updating them. The message components are the only which really need to be updated:

However, that gets tedious when you have many of them. That's one of the reasons why PrimeFaces Selectors exist. Those message components have in the generated HTML output a common style class of ui-message, so the following should also do:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@(.ui-message)" />
</h:form>
@(...)

The @parent updates only the parent component, which thus covers the current component and all siblings and their children. This is more useful if you have separated the form in sane groups with each its own responsibility. The @this updates, obviously, only the current component. Normally, this is only necessary when you need to change one of the component's own HTML attributes in the action method. E.g.

<p:commandButton action="#{bean.action}" update="@this" 
    oncomplete="doSomething('#{bean.value}')" />

Imagine that the oncomplete needs to work with the value which is changed in action, then this construct wouldn't have worked if the component isn't updated, for the simple reason that oncomplete is part of generated HTML output (and thus all EL expressions in there are evaluated during render response).

The @all updates the entire document, which should be used with care. Normally, you'd like to use a true GET request for this instead by either a plain link (<a> or <h:link>) or a redirect-after-POST by ?faces-redirect=true or ExternalContext#redirect(). In effects, process="@form" update="@all" has exactly the same effect as a non-ajax (non-partial) submit. In my entire JSF career, the only sensible use case I encountered for @all is to display an error page in its entirety in case an exception occurs during an ajax request. See also What is the correct way to deal with JSF 2.0 exceptions for AJAXified components?

The standard JSF equivalent to the PrimeFaces specific update is render from <f:ajax render>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Both update and render defaults to @none (which is, "nothing").

When I use update="" then the managed property of the backing bean does not get set and my @PostConstruct routine fails. Any thoughts? EDIT:If you rely a managed property of #{param} being present in the subsequent POST requests, then you need to include it as <f:param> in the UICommand components.

may a process/update of a panelGroup will process/update the contents of this panelGroup ex : <h:panelGroup id="pgId">//input texts goes here<h:panelGroup><p:commandLink process="pgId" update="pgId"/>

Thx @BalusC for this very nice explanation!

@BalusC You said we need to indicate @this in case of ActionSource so the action be called, although if I look into Primefaces showcase in link process="@this" is not set and it works well, why that?

@Rapster: because process is not set, so it uses default value of @form. This is also explained in above answer.

Understanding PrimeFaces process/update and JSF f:ajax execute/render ...

jsf primefaces process updates
Rectangle 27 214

The process attribute is server side and can only affect UIComponents implementing EditableValueHolder (input fields) or ActionSource (command fields). The process attribute tells JSF, using a space-separated list of client IDs, which components exactly must be processed through the entire JSF lifecycle upon (partial) form submit.

JSF will then apply the request values (finding HTTP request parameter based on component's own client ID and then either setting it as submitted value in case of EditableValueHolder components or queueing a new ActionEvent in case of ActionSource components), perform conversion, validation and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false during apply request values phase will also be skipped as part of safeguard against tampered requests.

Note that it's in case of ActionSource components (such as <p:commandButton>) very important that you also include the component itself in the process attribute, particularly if you intend to invoke the action associated with the component. So the below example which intends to process only certain input component(s) when a certain command component is invoked ain't gonna work:

It would only process the #{bean.foo} and not the #{bean.action}. You'd need to include the command component itself as well:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="@this foo" action="#{bean.action}" />

Or, as you apparently found out, using @parent if they happen to be the only components having a common parent:

<p:panel><!-- Type doesn't matter, as long as it's a common parent. -->
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@parent" action="#{bean.action}" />
</p:panel>

Or, if they both happen to be the only components of the parent UIForm component, then you can also use @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@form" action="#{bean.action}" />
</h:form>

This is sometimes undesirable if the form contains more input components which you'd like to skip in processing, more than often in cases when you'd like to update another input component(s) or some UI section based on the current input component in an ajax listener method. You namely don't want that validation errors on other input components are preventing the ajax listener method from being executed.

Then there's the @all. This has no special effect in process attribute, but only in update attribute. A process="@all" behaves exactly the same as process="@form". HTML doesn't support submitting multiple forms at once anyway.

There's by the way also a @none which may be useful in case you absolutely don't need to process anything, but only want to update some specific parts via update, particularly those sections whose content doesn't depend on submitted values or action listeners.

The update attribute is client side and can affect the HTML representation of all UIComponents. The update attribute tells JavaScript (the one responsible for handling the ajax request/response), using a space-separated list of client IDs, which parts in the HTML DOM tree need to be updated as response to the form submit.

JSF will then prepare the right ajax response for that, containing only the requested parts to update. JSF will skip all other components which are not covered by update attribute in the ajax response, hereby keeping the response payload small. Also, components whose rendered attribute evaluates to false during render response phase will be skipped. Note that even though it would return true, JavaScript cannot update it in the HTML DOM tree if it was initially false. You'd need to wrap it or update its parent instead. See also Ajax update/render does not work on a component which has rendered attribute.

Usually, you'd like to update only the components which really need to be "refreshed" in the client side upon (partial) form submit. The example below updates the entire parent form via @form:

process
@form

Whilst that may work fine, the update of input and command components is in this particular example unnecessary. Unless you change the model values foo and bar inside action method (which would in turn be unintuitive in UX perspective), there's no point of updating them. The message components are the only which really need to be updated:

However, that gets tedious when you have many of them. That's one of the reasons why PrimeFaces Selectors exist. Those message components have in the generated HTML output a common style class of ui-message, so the following should also do:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@(.ui-message)" />
</h:form>
@(...)

The @parent updates only the parent component, which thus covers the current component and all siblings and their children. This is more useful if you have separated the form in sane groups with each its own responsibility. The @this updates, obviously, only the current component. Normally, this is only necessary when you need to change one of the component's own HTML attributes in the action method. E.g.

<p:commandButton action="#{bean.action}" update="@this" 
    oncomplete="doSomething('#{bean.value}')" />

Imagine that the oncomplete needs to work with the value which is changed in action, then this construct wouldn't have worked if the component isn't updated, for the simple reason that oncomplete is part of generated HTML output (and thus all EL expressions in there are evaluated during render response).

The @all updates the entire document, which should be used with care. Normally, you'd like to use a true GET request for this instead by either a plain link (<a> or <h:link>) or a redirect-after-POST by ?faces-redirect=true or ExternalContext#redirect(). In effects, process="@form" update="@all" has exactly the same effect as a non-ajax (non-partial) submit. In my entire JSF career, the only sensible use case I encountered for @all is to display an error page in its entirety in case an exception occurs during an ajax request. See also What is the correct way to deal with JSF 2.0 exceptions for AJAXified components?

The standard JSF equivalent to the PrimeFaces specific update is render from <f:ajax render>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Both update and render defaults to @none (which is, "nothing").

When I use update="" then the managed property of the backing bean does not get set and my @PostConstruct routine fails. Any thoughts? EDIT:If you rely a managed property of #{param} being present in the subsequent POST requests, then you need to include it as <f:param> in the UICommand components.

may a process/update of a panelGroup will process/update the contents of this panelGroup ex : <h:panelGroup id="pgId">//input texts goes here<h:panelGroup><p:commandLink process="pgId" update="pgId"/>

Thx @BalusC for this very nice explanation!

@BalusC You said we need to indicate @this in case of ActionSource so the action be called, although if I look into Primefaces showcase in link process="@this" is not set and it works well, why that?

@Rapster: because process is not set, so it uses default value of @form. This is also explained in above answer.

Understanding PrimeFaces process/update and JSF f:ajax execute/render ...

jsf primefaces process updates
Rectangle 27 214

The process attribute is server side and can only affect UIComponents implementing EditableValueHolder (input fields) or ActionSource (command fields). The process attribute tells JSF, using a space-separated list of client IDs, which components exactly must be processed through the entire JSF lifecycle upon (partial) form submit.

JSF will then apply the request values (finding HTTP request parameter based on component's own client ID and then either setting it as submitted value in case of EditableValueHolder components or queueing a new ActionEvent in case of ActionSource components), perform conversion, validation and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false during apply request values phase will also be skipped as part of safeguard against tampered requests.

Note that it's in case of ActionSource components (such as <p:commandButton>) very important that you also include the component itself in the process attribute, particularly if you intend to invoke the action associated with the component. So the below example which intends to process only certain input component(s) when a certain command component is invoked ain't gonna work:

It would only process the #{bean.foo} and not the #{bean.action}. You'd need to include the command component itself as well:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="@this foo" action="#{bean.action}" />

Or, as you apparently found out, using @parent if they happen to be the only components having a common parent:

<p:panel><!-- Type doesn't matter, as long as it's a common parent. -->
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@parent" action="#{bean.action}" />
</p:panel>

Or, if they both happen to be the only components of the parent UIForm component, then you can also use @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@form" action="#{bean.action}" />
</h:form>

This is sometimes undesirable if the form contains more input components which you'd like to skip in processing, more than often in cases when you'd like to update another input component(s) or some UI section based on the current input component in an ajax listener method. You namely don't want that validation errors on other input components are preventing the ajax listener method from being executed.

Then there's the @all. This has no special effect in process attribute, but only in update attribute. A process="@all" behaves exactly the same as process="@form". HTML doesn't support submitting multiple forms at once anyway.

There's by the way also a @none which may be useful in case you absolutely don't need to process anything, but only want to update some specific parts via update, particularly those sections whose content doesn't depend on submitted values or action listeners.

The update attribute is client side and can affect the HTML representation of all UIComponents. The update attribute tells JavaScript (the one responsible for handling the ajax request/response), using a space-separated list of client IDs, which parts in the HTML DOM tree need to be updated as response to the form submit.

JSF will then prepare the right ajax response for that, containing only the requested parts to update. JSF will skip all other components which are not covered by update attribute in the ajax response, hereby keeping the response payload small. Also, components whose rendered attribute evaluates to false during render response phase will be skipped. Note that even though it would return true, JavaScript cannot update it in the HTML DOM tree if it was initially false. You'd need to wrap it or update its parent instead. See also Ajax update/render does not work on a component which has rendered attribute.

Usually, you'd like to update only the components which really need to be "refreshed" in the client side upon (partial) form submit. The example below updates the entire parent form via @form:

process
@form

Whilst that may work fine, the update of input and command components is in this particular example unnecessary. Unless you change the model values foo and bar inside action method (which would in turn be unintuitive in UX perspective), there's no point of updating them. The message components are the only which really need to be updated:

However, that gets tedious when you have many of them. That's one of the reasons why PrimeFaces Selectors exist. Those message components have in the generated HTML output a common style class of ui-message, so the following should also do:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@(.ui-message)" />
</h:form>
@(...)

The @parent updates only the parent component, which thus covers the current component and all siblings and their children. This is more useful if you have separated the form in sane groups with each its own responsibility. The @this updates, obviously, only the current component. Normally, this is only necessary when you need to change one of the component's own HTML attributes in the action method. E.g.

<p:commandButton action="#{bean.action}" update="@this" 
    oncomplete="doSomething('#{bean.value}')" />

Imagine that the oncomplete needs to work with the value which is changed in action, then this construct wouldn't have worked if the component isn't updated, for the simple reason that oncomplete is part of generated HTML output (and thus all EL expressions in there are evaluated during render response).

The @all updates the entire document, which should be used with care. Normally, you'd like to use a true GET request for this instead by either a plain link (<a> or <h:link>) or a redirect-after-POST by ?faces-redirect=true or ExternalContext#redirect(). In effects, process="@form" update="@all" has exactly the same effect as a non-ajax (non-partial) submit. In my entire JSF career, the only sensible use case I encountered for @all is to display an error page in its entirety in case an exception occurs during an ajax request. See also What is the correct way to deal with JSF 2.0 exceptions for AJAXified components?

The standard JSF equivalent to the PrimeFaces specific update is render from <f:ajax render>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Both update and render defaults to @none (which is, "nothing").

When I use update="" then the managed property of the backing bean does not get set and my @PostConstruct routine fails. Any thoughts? EDIT:If you rely a managed property of #{param} being present in the subsequent POST requests, then you need to include it as <f:param> in the UICommand components.

may a process/update of a panelGroup will process/update the contents of this panelGroup ex : <h:panelGroup id="pgId">//input texts goes here<h:panelGroup><p:commandLink process="pgId" update="pgId"/>

Thx @BalusC for this very nice explanation!

@BalusC You said we need to indicate @this in case of ActionSource so the action be called, although if I look into Primefaces showcase in link process="@this" is not set and it works well, why that?

@Rapster: because process is not set, so it uses default value of @form. This is also explained in above answer.

Understanding PrimeFaces process/update and JSF f:ajax execute/render ...

jsf primefaces process updates
Rectangle 27 214

The process attribute is server side and can only affect UIComponents implementing EditableValueHolder (input fields) or ActionSource (command fields). The process attribute tells JSF, using a space-separated list of client IDs, which components exactly must be processed through the entire JSF lifecycle upon (partial) form submit.

JSF will then apply the request values (finding HTTP request parameter based on component's own client ID and then either setting it as submitted value in case of EditableValueHolder components or queueing a new ActionEvent in case of ActionSource components), perform conversion, validation and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false during apply request values phase will also be skipped as part of safeguard against tampered requests.

Note that it's in case of ActionSource components (such as <p:commandButton>) very important that you also include the component itself in the process attribute, particularly if you intend to invoke the action associated with the component. So the below example which intends to process only certain input component(s) when a certain command component is invoked ain't gonna work:

It would only process the #{bean.foo} and not the #{bean.action}. You'd need to include the command component itself as well:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="@this foo" action="#{bean.action}" />

Or, as you apparently found out, using @parent if they happen to be the only components having a common parent:

<p:panel><!-- Type doesn't matter, as long as it's a common parent. -->
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@parent" action="#{bean.action}" />
</p:panel>

Or, if they both happen to be the only components of the parent UIForm component, then you can also use @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@form" action="#{bean.action}" />
</h:form>

This is sometimes undesirable if the form contains more input components which you'd like to skip in processing, more than often in cases when you'd like to update another input component(s) or some UI section based on the current input component in an ajax listener method. You namely don't want that validation errors on other input components are preventing the ajax listener method from being executed.

Then there's the @all. This has no special effect in process attribute, but only in update attribute. A process="@all" behaves exactly the same as process="@form". HTML doesn't support submitting multiple forms at once anyway.

There's by the way also a @none which may be useful in case you absolutely don't need to process anything, but only want to update some specific parts via update, particularly those sections whose content doesn't depend on submitted values or action listeners.

The update attribute is client side and can affect the HTML representation of all UIComponents. The update attribute tells JavaScript (the one responsible for handling the ajax request/response), using a space-separated list of client IDs, which parts in the HTML DOM tree need to be updated as response to the form submit.

JSF will then prepare the right ajax response for that, containing only the requested parts to update. JSF will skip all other components which are not covered by update attribute in the ajax response, hereby keeping the response payload small. Also, components whose rendered attribute evaluates to false during render response phase will be skipped. Note that even though it would return true, JavaScript cannot update it in the HTML DOM tree if it was initially false. You'd need to wrap it or update its parent instead. See also Ajax update/render does not work on a component which has rendered attribute.

Usually, you'd like to update only the components which really need to be "refreshed" in the client side upon (partial) form submit. The example below updates the entire parent form via @form:

process
@form

Whilst that may work fine, the update of input and command components is in this particular example unnecessary. Unless you change the model values foo and bar inside action method (which would in turn be unintuitive in UX perspective), there's no point of updating them. The message components are the only which really need to be updated:

However, that gets tedious when you have many of them. That's one of the reasons why PrimeFaces Selectors exist. Those message components have in the generated HTML output a common style class of ui-message, so the following should also do:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@(.ui-message)" />
</h:form>
@(...)

The @parent updates only the parent component, which thus covers the current component and all siblings and their children. This is more useful if you have separated the form in sane groups with each its own responsibility. The @this updates, obviously, only the current component. Normally, this is only necessary when you need to change one of the component's own HTML attributes in the action method. E.g.

<p:commandButton action="#{bean.action}" update="@this" 
    oncomplete="doSomething('#{bean.value}')" />

Imagine that the oncomplete needs to work with the value which is changed in action, then this construct wouldn't have worked if the component isn't updated, for the simple reason that oncomplete is part of generated HTML output (and thus all EL expressions in there are evaluated during render response).

The @all updates the entire document, which should be used with care. Normally, you'd like to use a true GET request for this instead by either a plain link (<a> or <h:link>) or a redirect-after-POST by ?faces-redirect=true or ExternalContext#redirect(). In effects, process="@form" update="@all" has exactly the same effect as a non-ajax (non-partial) submit. In my entire JSF career, the only sensible use case I encountered for @all is to display an error page in its entirety in case an exception occurs during an ajax request. See also What is the correct way to deal with JSF 2.0 exceptions for AJAXified components?

The standard JSF equivalent to the PrimeFaces specific update is render from <f:ajax render>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Both update and render defaults to @none (which is, "nothing").

When I use update="" then the managed property of the backing bean does not get set and my @PostConstruct routine fails. Any thoughts? EDIT:If you rely a managed property of #{param} being present in the subsequent POST requests, then you need to include it as <f:param> in the UICommand components.

may a process/update of a panelGroup will process/update the contents of this panelGroup ex : <h:panelGroup id="pgId">//input texts goes here<h:panelGroup><p:commandLink process="pgId" update="pgId"/>

Thx @BalusC for this very nice explanation!

@BalusC You said we need to indicate @this in case of ActionSource so the action be called, although if I look into Primefaces showcase in link process="@this" is not set and it works well, why that?

@Rapster: because process is not set, so it uses default value of @form. This is also explained in above answer.

Understanding PrimeFaces process/update and JSF f:ajax execute/render ...

jsf primefaces process updates
Rectangle 27 1

There were a number of bugs associated with AJAX updates of a dataTable component for actions triggered within components of a dataTable. Most of these should have been fixed in the latest Primefaces version 3 release however you didn't really state which version of Primefaces you are using.

I posted a workaround to this in a previous answer here. Essentially you would from the client side invoke a javascript to manually invoke a click event on a hidden button outside of the dataTable.

jsf - PrimeFaces update - Stack Overflow

jsf primefaces
Rectangle 27 203

The process attribute is server side and can only affect UIComponents implementing EditableValueHolder (input fields) or ActionSource (command fields). The process attribute tells JSF, using a space-separated list of client IDs, which components exactly must be processed through the entire JSF lifecycle upon (partial) form submit.

JSF will then apply the request values (finding HTTP request parameter based on component's own client ID and then either setting it as submitted value in case of EditableValueHolder components or queueing a new ActionEvent in case of ActionSource components), perform conversion, validation and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false during apply request values phase will also be skipped as part of safeguard against tampered requests.

Note that it's in case of ActionSource components (such as <p:commandButton>) very important that you also include the component itself in the process attribute, particularly if you intend to invoke the action associated with the component. So the below example which intends to process only certain input component(s) when a certain command component is invoked ain't gonna work:

It would only process the #{bean.foo} and not the #{bean.action}. You'd need to include the command component itself as well:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="@this foo" action="#{bean.action}" />

Or, as you apparently found out, using @parent if they happen to be the only components having a common parent:

<p:panel><!-- Type doesn't matter, as long as it's a common parent. -->
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@parent" action="#{bean.action}" />
</p:panel>

Or, if they both happen to be the only components of the parent UIForm component, then you can also use @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@form" action="#{bean.action}" />
</h:form>

This is sometimes undesirable if the form contains more input components which you'd like to skip in processing, more than often in cases when you'd like to update another input component(s) or some UI section based on the current input component in an ajax listener method. You namely don't want that validation errors on other input components are preventing the ajax listener method from being executed.

Then there's the @all. This has no special effect in process attribute, but only in update attribute. A process="@all" behaves exactly the same as process="@form". HTML doesn't support submitting multiple forms at once anyway.

There's by the way also a @none which may be useful in case you absolutely don't need to process anything, but only want to update some specific parts via update, particularly those sections whose content doesn't depend on submitted values or action listeners.

The update attribute is client side and can affect the HTML representation of all UIComponents. The update attribute tells JavaScript (the one responsible for handling the ajax request/response), using a space-separated list of client IDs, which parts in the HTML DOM tree need to be updated as response to the form submit.

JSF will then prepare the right ajax response for that, containing only the requested parts to update. JSF will skip all other components which are not covered by update attribute in the ajax response, hereby keeping the response payload small. Also, components whose rendered attribute evaluates to false during render response phase will be skipped. Note that even though it would return true, JavaScript cannot update it in the HTML DOM tree if it was initially false. You'd need to wrap it or update its parent instead. See also Ajax update/render does not work on a component which has rendered attribute.

Usually, you'd like to update only the components which really need to be "refreshed" in the client side upon (partial) form submit. The example below updates the entire parent form via @form:

process
@form

Whilst that may work fine, the update of input and command components is in this particular example unnecessary. Unless you change the model values foo and bar inside action method (which would in turn be unintuitive in UX perspective), there's no point of updating them. The message components are the only which really need to be updated:

However, that gets tedious when you have many of them. That's one of the reasons why PrimeFaces Selectors exist. Those message components have in the generated HTML output a common style class of ui-message, so the following should also do:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@(.ui-message)" />
</h:form>
@(...)

The @parent updates only the parent component, which thus covers the current component and all siblings and their children. This is more useful if you have separated the form in sane groups with each its own responsibility. The @this updates, obviously, only the current component. Normally, this is only necessary when you need to change one of the component's own HTML attributes in the action method. E.g.

<p:commandButton action="#{bean.action}" update="@this" 
    oncomplete="doSomething('#{bean.value}')" />

Imagine that the oncomplete needs to work with the value which is changed in action, then this construct wouldn't have worked if the component isn't updated, for the simple reason that oncomplete is part of generated HTML output (and thus all EL expressions in there are evaluated during render response).

The @all updates the entire document, which should be used with care. Normally, you'd like to use a true GET request for this instead by either a plain link (<a> or <h:link>) or a redirect-after-POST by ?faces-redirect=true or ExternalContext#redirect(). In effects, process="@form" update="@all" has exactly the same effect as a non-ajax (non-partial) submit. In my entire JSF career, the only sensible use case I encountered for @all is to display an error page in its entirety in case an exception occurs during an ajax request. See also What is the correct way to deal with JSF 2.0 exceptions for AJAXified components?

The standard JSF equivalent to the PrimeFaces specific update is render from <f:ajax render>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Both update and render defaults to @none (which is, "nothing").

When I use update="" then the managed property of the backing bean does not get set and my @PostConstruct routine fails. Any thoughts? EDIT:If you rely a managed property of #{param} being present in the subsequent POST requests, then you need to include it as <f:param> in the UICommand components.

may a process/update of a panelGroup will process/update the contents of this panelGroup ex : <h:panelGroup id="pgId">//input texts goes here<h:panelGroup><p:commandLink process="pgId" update="pgId"/>

Thx @BalusC for this very nice explanation!

@BalusC You said we need to indicate @this in case of ActionSource so the action be called, although if I look into Primefaces showcase in link process="@this" is not set and it works well, why that?

@Rapster: because process is not set, so it uses default value of @form. This is also explained in above answer.

Understanding PrimeFaces process/update and JSF f:ajax execute/render ...

jsf primefaces process updates
Rectangle 27 201

The process attribute is server side and can only affect UIComponents implementing EditableValueHolder (input fields) or ActionSource (command fields). The process attribute tells JSF, using a space-separated list of client IDs, which components exactly must be processed through the entire JSF lifecycle upon (partial) form submit.

JSF will then apply the request values (finding HTTP request parameter based on component's own client ID and then either setting it as submitted value in case of EditableValueHolder components or queueing a new ActionEvent in case of ActionSource components), perform conversion, validation and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false during apply request values phase will also be skipped as part of safeguard against tampered requests.

Note that it's in case of ActionSource components (such as <p:commandButton>) very important that you also include the component itself in the process attribute, particularly if you intend to invoke the action associated with the component. So the below example which intends to process only certain input component(s) when a certain command component is invoked ain't gonna work:

It would only process the #{bean.foo} and not the #{bean.action}. You'd need to include the command component itself as well:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="@this foo" action="#{bean.action}" />

Or, as you apparently found out, using @parent if they happen to be the only components having a common parent:

<p:panel><!-- Type doesn't matter, as long as it's a common parent. -->
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@parent" action="#{bean.action}" />
</p:panel>

Or, if they both happen to be the only components of the parent UIForm component, then you can also use @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@form" action="#{bean.action}" />
</h:form>

This is sometimes undesirable if the form contains more input components which you'd like to skip in processing, more than often in cases when you'd like to update another input component(s) or some UI section based on the current input component in an ajax listener method. You namely don't want that validation errors on other input components are preventing the ajax listener method from being executed.

Then there's the @all. This has no special effect in process attribute, but only in update attribute. A process="@all" behaves exactly the same as process="@form". HTML doesn't support submitting multiple forms at once anyway.

There's by the way also a @none which may be useful in case you absolutely don't need to process anything, but only want to update some specific parts via update, particularly those sections whose content doesn't depend on submitted values or action listeners.

The update attribute is client side and can affect the HTML representation of all UIComponents. The update attribute tells JavaScript (the one responsible for handling the ajax request/response), using a space-separated list of client IDs, which parts in the HTML DOM tree need to be updated as response to the form submit.

JSF will then prepare the right ajax response for that, containing only the requested parts to update. JSF will skip all other components which are not covered by update attribute in the ajax response, hereby keeping the response payload small. Also, components whose rendered attribute evaluates to false during render response phase will be skipped. Note that even though it would return true, JavaScript cannot update it in the HTML DOM tree if it was initially false. You'd need to wrap it or update its parent instead. See also Ajax update/render does not work on a component which has rendered attribute.

Usually, you'd like to update only the components which really need to be "refreshed" in the client side upon (partial) form submit. The example below updates the entire parent form via @form:

process
@form

Whilst that may work fine, the update of input and command components is in this particular example unnecessary. Unless you change the model values foo and bar inside action method (which would in turn be unintuitive in UX perspective), there's no point of updating them. The message components are the only which really need to be updated:

However, that gets tedious when you have many of them. That's one of the reasons why PrimeFaces Selectors exist. Those message components have in the generated HTML output a common style class of ui-message, so the following should also do:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@(.ui-message)" />
</h:form>
@(...)

The @parent updates only the parent component, which thus covers the current component and all siblings and their children. This is more useful if you have separated the form in sane groups with each its own responsibility. The @this updates, obviously, only the current component. Normally, this is only necessary when you need to change one of the component's own HTML attributes in the action method. E.g.

<p:commandButton action="#{bean.action}" update="@this" 
    oncomplete="doSomething('#{bean.value}')" />

Imagine that the oncomplete needs to work with the value which is changed in action, then this construct wouldn't have worked if the component isn't updated, for the simple reason that oncomplete is part of generated HTML output (and thus all EL expressions in there are evaluated during render response).

The @all updates the entire document, which should be used with care. Normally, you'd like to use a true GET request for this instead by either a plain link (<a> or <h:link>) or a redirect-after-POST by ?faces-redirect=true or ExternalContext#redirect(). In effects, process="@form" update="@all" has exactly the same effect as a non-ajax (non-partial) submit. In my entire JSF career, the only sensible use case I encountered for @all is to display an error page in its entirety in case an exception occurs during an ajax request. See also What is the correct way to deal with JSF 2.0 exceptions for AJAXified components?

The standard JSF equivalent to the PrimeFaces specific update is render from <f:ajax render>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Both update and render defaults to @none (which is, "nothing").

When I use update="" then the managed property of the backing bean does not get set and my @PostConstruct routine fails. Any thoughts? EDIT:If you rely a managed property of #{param} being present in the subsequent POST requests, then you need to include it as <f:param> in the UICommand components.

may a process/update of a panelGroup will process/update the contents of this panelGroup ex : <h:panelGroup id="pgId">//input texts goes here<h:panelGroup><p:commandLink process="pgId" update="pgId"/>

Thx @BalusC for this very nice explanation!

@BalusC You said we need to indicate @this in case of ActionSource so the action be called, although if I look into Primefaces showcase in link process="@this" is not set and it works well, why that?

@Rapster: because process is not set, so it uses default value of @form. This is also explained in above answer.

Understanding PrimeFaces process/update and JSF f:ajax execute/render ...

jsf primefaces process updates
Rectangle 27 201

The process attribute is server side and can only affect UIComponents implementing EditableValueHolder (input fields) or ActionSource (command fields). The process attribute tells JSF, using a space-separated list of client IDs, which components exactly must be processed through the entire JSF lifecycle upon (partial) form submit.

JSF will then apply the request values (finding HTTP request parameter based on component's own client ID and then either setting it as submitted value in case of EditableValueHolder components or queueing a new ActionEvent in case of ActionSource components), perform conversion, validation and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false during apply request values phase will also be skipped as part of safeguard against tampered requests.

Note that it's in case of ActionSource components (such as <p:commandButton>) very important that you also include the component itself in the process attribute, particularly if you intend to invoke the action associated with the component. So the below example which intends to process only certain input component(s) when a certain command component is invoked ain't gonna work:

It would only process the #{bean.foo} and not the #{bean.action}. You'd need to include the command component itself as well:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="@this foo" action="#{bean.action}" />

Or, as you apparently found out, using @parent if they happen to be the only components having a common parent:

<p:panel><!-- Type doesn't matter, as long as it's a common parent. -->
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@parent" action="#{bean.action}" />
</p:panel>

Or, if they both happen to be the only components of the parent UIForm component, then you can also use @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@form" action="#{bean.action}" />
</h:form>

This is sometimes undesirable if the form contains more input components which you'd like to skip in processing, more than often in cases when you'd like to update another input component(s) or some UI section based on the current input component in an ajax listener method. You namely don't want that validation errors on other input components are preventing the ajax listener method from being executed.

Then there's the @all. This has no special effect in process attribute, but only in update attribute. A process="@all" behaves exactly the same as process="@form". HTML doesn't support submitting multiple forms at once anyway.

There's by the way also a @none which may be useful in case you absolutely don't need to process anything, but only want to update some specific parts via update, particularly those sections whose content doesn't depend on submitted values or action listeners.

The update attribute is client side and can affect the HTML representation of all UIComponents. The update attribute tells JavaScript (the one responsible for handling the ajax request/response), using a space-separated list of client IDs, which parts in the HTML DOM tree need to be updated as response to the form submit.

JSF will then prepare the right ajax response for that, containing only the requested parts to update. JSF will skip all other components which are not covered by update attribute in the ajax response, hereby keeping the response payload small. Also, components whose rendered attribute evaluates to false during render response phase will be skipped. Note that even though it would return true, JavaScript cannot update it in the HTML DOM tree if it was initially false. You'd need to wrap it or update its parent instead. See also Ajax update/render does not work on a component which has rendered attribute.

Usually, you'd like to update only the components which really need to be "refreshed" in the client side upon (partial) form submit. The example below updates the entire parent form via @form:

process
@form

Whilst that may work fine, the update of input and command components is in this particular example unnecessary. Unless you change the model values foo and bar inside action method (which would in turn be unintuitive in UX perspective), there's no point of updating them. The message components are the only which really need to be updated:

However, that gets tedious when you have many of them. That's one of the reasons why PrimeFaces Selectors exist. Those message components have in the generated HTML output a common style class of ui-message, so the following should also do:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@(.ui-message)" />
</h:form>
@(...)

The @parent updates only the parent component, which thus covers the current component and all siblings and their children. This is more useful if you have separated the form in sane groups with each its own responsibility. The @this updates, obviously, only the current component. Normally, this is only necessary when you need to change one of the component's own HTML attributes in the action method. E.g.

<p:commandButton action="#{bean.action}" update="@this" 
    oncomplete="doSomething('#{bean.value}')" />

Imagine that the oncomplete needs to work with the value which is changed in action, then this construct wouldn't have worked if the component isn't updated, for the simple reason that oncomplete is part of generated HTML output (and thus all EL expressions in there are evaluated during render response).

The @all updates the entire document, which should be used with care. Normally, you'd like to use a true GET request for this instead by either a plain link (<a> or <h:link>) or a redirect-after-POST by ?faces-redirect=true or ExternalContext#redirect(). In effects, process="@form" update="@all" has exactly the same effect as a non-ajax (non-partial) submit. In my entire JSF career, the only sensible use case I encountered for @all is to display an error page in its entirety in case an exception occurs during an ajax request. See also What is the correct way to deal with JSF 2.0 exceptions for AJAXified components?

The standard JSF equivalent to the PrimeFaces specific update is render from <f:ajax render>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Both update and render defaults to @none (which is, "nothing").

When I use update="" then the managed property of the backing bean does not get set and my @PostConstruct routine fails. Any thoughts? EDIT:If you rely a managed property of #{param} being present in the subsequent POST requests, then you need to include it as <f:param> in the UICommand components.

may a process/update of a panelGroup will process/update the contents of this panelGroup ex : <h:panelGroup id="pgId">//input texts goes here<h:panelGroup><p:commandLink process="pgId" update="pgId"/>

Thx @BalusC for this very nice explanation!

@BalusC You said we need to indicate @this in case of ActionSource so the action be called, although if I look into Primefaces showcase in link process="@this" is not set and it works well, why that?

@Rapster: because process is not set, so it uses default value of @form. This is also explained in above answer.

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Understanding PrimeFaces process/update and JSF f:ajax execute/render ...

jsf primefaces process updates