h
Tag commandLink

Render an HTML "a" anchor element that acts like a form submit button when clicked.

General Behaviour

Both the encode and decode behavior require the ability to get the id/name for a hidden field, which may be rendered in markup or which may be programmatically added via client DOM manipulation, whose value is set by the JavaScript form submit. This name must be constructed as follows:

• Get the clientId for the form of which this component is a child.

• Append NamingContainer.SEPARATOR_CHAR.

• Append a constant string that is the same for all command link components in the tree.

In the following text, this String is called hiddenFieldName.

Decode Behavior

Obtain the "clientId" property of the component. Obtain the Map from the "requestParameterMap" property of the ExternalContext. Derive hiddenFieldName as above. Get the entry in the Map under the key that is the hiddenFieldName. If the there is no entry, or the entry is the empty String, or the entry is not equal to the value of the "clientId" property, return immediately. If there is an entry, and its value is equal to the value of the "clientId" property, create a new javax.faces.event.ActionEvent instance around the component and call queueActionEvent() on the component, passing the event.

Encode Behavior

If the value of the disabled attribute is true, render a span element. Render all the ignored-by-renderer attributes and the target attribute as ignored-by-renderer attributes on the span, even though the target attribute will have no effect on a span. Render the current value of the component as the content of the span. Return.

If the disabled attribute is not present, or its value is false, render an HTML a element. Render "#" as the value of the "href" attribute. Render the current value of the component as the link text if it is specified. Render JavaScript that is functionally equivalent to the following as the value of the "onclick" attribute:

document.forms['CLIENT_ID']['hiddenFieldName'].value='CLIENT_ID'; document.forms['CLIENT_ID']['PARAM1_NAME'].value='PARAM1_VALUE'; document.forms['CLIENT_ID']['PARAM2_NAME'].value='PARAM2_VALUE'; document.forms['CLIENT_ID'].submit(); return false;

where hiddenFieldName is as described above, CLIENT_ID is the clientId of the UICommand component, PARAM*_NAME and PARAM*_VALUE are the names and values, respectively, of any nested UIParameter children. The name and the value must be URLEncoded. Note that the required url encoding is handled by ResponseWrter.writeAttribute(). If an "onclick" attribute was specified by the user, render this JavaScript in a function, and render the user's JavaScript in a function. Render both functions in a choice function as follows:

var a=function(){#USER_FUNCTION#}; var b=function(){#JSF_FUNCTION#}; return (a()==false) ? false : b();

where #USER_FUNCTION# is the user's JavaScript and #JSF_FUNCTION# is the JavaScript rendered by JSF. The choice function should operate such that if the user's JavaScript returns true, then the rendered JavaScript will also execute.

If the "styleClass" attribute is specified, render its value as the value of the "class" attribute. Render any non-UIParameter output children as normal inside of the "a" element. These will appear as the link text. Allow the form renderer to output a single "input" element (for the entire page, regardless of how many command link components are in the page) of "type" "hidden" whose "name" is the value of hiddenFieldName, and which must not have a "value" attribute. Multiple occurrences of command link components in the tree should not cause multiple hiddenFieldName hidden fields. Allow the form renderer to output an "input" element of "type" "hidden" for each of the nested UIParameter children, taking the name property (but not the value) from each one in turn. If the "disabled" attribute is specified, do not render the HTML "a" anchor element or its "href" attribute. Instead, render a "span" element. If the "styleClass" attribute is specified, render its value as the value of the "class" attribute on the "span". Render any ignored-by-renderer attributes on the "span". The content of the span element comes from the value of the component or its children as specified above.

If the user specified a target attribute, its value must be set using javascript since the onclick handler will prevent the target attribute from being generated. This must be accomplished using JavaScript that is equivalent to the following.

document.forms['CLIENT_ID'].target='TARGET';

Where TARGET is the value of the target attribute on the JSP tag.

<h:commandLink id="start_a" value="enter flow-a" action="flow-a">
   <f:attribute name="to-flow-document-id" value="unique"/>
 </h:commandLink>