Here the primary key is provided by the managed bean "myBean". The content is stored in the request variable "component".

<fx:content pk="#{myBean.pk}" var="component">
    Component: #{component.name} <br/>

    <!-- Resolve a content reference to a project content with $ -->
    Assigned project: #{component.project$.name} (PK = #{component.project})<br/>

    <!-- Iterate over all elements of the "comment" group with $list -->
    <ui:repeat var="comment" value="#{component.comment$list}">
        <h5>Comment by #{comment.author$.caption} on #{comment.created_at}:</h5>
        <p>#{comment.text}</p>
    </ui:repeat>

    <!-- Access via full XPath -->
    #{component['/comment[5]/author$.caption']}
</fx:content>

<a4j:form id="frm">
    <fx:content pk="#{myBean.pk}" var="component">

        <!-- Render an input row for the "name" property of the enclosing content tag  -->
        <fx:value property="name"/>

        <!-- Save content using the FxContentViewBean, pass the content instance
             stored in component_content" via f:setPropertyActionListener -->
        <h:commandButton action="#{fxContentViewBean.save}" value="Create component">
            <f:setPropertyActionListener target="#{fxContentViewBean.content}" value="#{component_content}"/>
        </h:commandButton>
    </fx:content>
</a4j:form>

<a4j:form id="frm">
    <fx:content id="componentView" typeName="Component" var="component">

        <!-- Render an input row for the "name" property of the enclosing content tag  -->
        <fx:value property="name"/>

        <!-- Save content using the FxContentViewBean, pass the content instance stored in "component_content"
             via f:setPropertyActionListener -->
        <h:commandButton action="#{fxContentViewBean.save}" value="Create component">
            <f:setPropertyActionListener target="#{fxContentViewBean.content}" value="#{component_content}"/>
        </h:commandButton>
    </fx:content>
</a4j:form>

Assume type "issue" has a group "comment" with multiplicity 1..n. In order to edit existing instances, you could iterate over the existing using the $list suffix. For creating a new "comment" group, you specify the XPath without multiplicities and set the "new" attribute.

<a4j:form id="frm">
    <fx:content pk="#{myBean.pk}" var="issue">
        <!-- Enter a new comment -->
        <fx:value property="comment/text" new="true"/>

        <!-- Save button etc... -->
    </fx:content>
</a4j:form>

<!-- Specify preserveContent="true" to keep structural changes made to the content instance -->
<fx:content pk="#{myBean.pk}" var="data" preserveContent="true">

    <!-- Show editors for all existing contact person groups stored under the XPath /contactPerson -->
    <ui:repeat var="contactPerson" value="#{data.contactPerson$listAll}">
        <fx:fieldSet legend="Contact Person">
            <fx:value var="contactPerson" property="name"/>
            <fx:value var="contactPerson" property="email"/>
        </fx:fieldSet>
    </ui:repeat>

    <!-- Render a button to add a new contact person group to the "data" content instance -->
    <h:commandButton action="#{fxContentViewBean.add}" value="Add another person">
        <!-- Pass the content instance to the JSF bean -->
        <f:setPropertyActionListener value="#{data_content}" target="#{fxContentViewBean.content}"/>

        <!-- Specify the XPath of the element to be added -->
        <f:setPropertyActionListener value="/CONTACTPERSON" target="#{fxContentViewBean.xpath}"/>
    </h:commandButton>

</fx:content>

Some content properties cannot be populated in a generic way. InputMappers wrap the FxValue provided by the content instance in another FxValue, for example a FxSelectOne select item value.

<a4j:form id="frm">
    <fx:content pk="#{myBean.pk}" var="issue">
        <!-- Provide a list of contents for this reference property -->
        <fx:value property="owner" inputMapper="#{myBean.accountMapper}"/>

        <!-- Save button etc... -->
    </fx:content>
</a4j:form>

In this very basic implementation the input mapper is constructed from a collection of PKs returned by our business method "someOtherBean.getAccountPks()". There already exists an input mapper for FxPK objects in the flexive framework that takes a select list and interprets the item IDs as PK IDs. A "real" input mapper would probably use less generic labels and use the account caption instead.

public class MyBean {
    public InputMapper getAccountMapper() {
        FxSelectListEdit selectList = new FxSelectList("Accounts").asEditable();
        for (FxPK pk: someOtherBean.getAccountPks()) {
            new FxSelectListItem(pk.getId(), selectList, -1, "Account " + pk);
        }
        return new FxPkSelectOneInputMapper(selectList);
    }
}