component.namingContainer.parent skips h:form

Question

I made a composite component, inside it is an <f:ajax> tag, and its "render" attribute is a parameter of the cc.

something like this:

    ...
    <cc:attribute name="additionalAjaxRenderIds" type="java.lang.String"></cc:attribute>
    ...
    <h:commandLink value="test" action="#{myBean.someAction}" id="testLink" >
        <f:ajax execute="@this" render="#{cc.attrs.additionalAjaxRenderIds} "/>
    </h:commandLink>
    ...

I use this cc inside a form, thats already in an outer naming container:

    <h:form id="myForm">
        ...
        <mycomp:myComponent id="myCC" additionalAjaxRenderIds=":#{component.namingContainer.parent.clientId}:myPanel" />
        <h:panelGroup id="myPanel">
            ...
        </h:panelGroup>
        ...
    </h:form>

The problem is, if i write

additionalAjaxRenderIds=":#{component.namingContainer.clientId}:myPanel"

i get this error:

<f:ajax> contains an unknown id ':j_idt44:myForm:myCC:myPanel' - cannot locate it in the context of the component testLink

while if i use this (+ .parent):

additionalAjaxRenderIds=":#{component.namingContainer.parent.clientId}:myPanel"

the error is:

<f:ajax> contains an unknown id ':j_idt44:myPanel' - cannot locate it in the context of the component testLink

instead of the expected id:

':j_idt44:myForm:myPanel'

so it seems like the parent of my cc's naming container is not the form, but the outer namingcontainer

Is there any way to: 1, get the right parent (the form) 2, evaluate the EL before i pass it as a parameter (so i can pass the calculated clientId to my cc instead of the EL expression, so the component wont refer to the commandLink tag, but to the h:form in which i put my cc)

I know i could use

additionalAjaxRenderIds=":#{component.namingContainer.parent.clientId}:myForm:myPanel" 

but i dont like that solution

Also, setting the form's prependId attribute to false breaks the whole component lookup (and the ajax tag too as a result)

Answer 1

EL expressions are not evaluated at the moment the component is built, but at the moment the attribute is accessed. In other words, they're runtime and not buildtime. The #{component} refers to the current UI component at the moment the EL expression is evaluated, which is in your particular case the <h:commandLink>. That explains the different outcome.

You need to approach this differently, without using #{component}.

E.g.

<h:form id="myForm" binding="#{myForm}">
    ...
    <mycomp:myComponent id="myCC" additionalAjaxRenderIds=":#{myForm.clientId}:myPanel" />
    <h:panelGroup id="myPanel">
        ...
    </h:panelGroup>
    ...
</h:form>

or

<h:form id="myForm">
    ...
    <mycomp:myComponent id="myCC" additionalAjaxRenderIds=":#{myPanel.clientId}" />
    <h:panelGroup id="myPanel" binding="#{myPanel}">
        ...
    </h:panelGroup>
    ...
</h:form>