Gang -
Just wanted to pass along some feedback from Paul Dijou. (Thanks for
reviewing this Paul!)
> Hi guys,
>
> Even if I find it awesome to have pass through attributes in JSF, I
> can't really find the current draft acceptable from a user
> perspective. It really gives me the feeling it's only half-baked. It
> does its job, yes, but it's so verbose, so heavy... Let's take a
> simple example. Here is a classic HTML5 usage of the input:
>
> <input type="email" placeholder="To..." autofocus="autofocus"
> multiple="multiple"/>
>
> How would I write it in JSF with the current proposal? Probably
> something like that:
>
> <h:inputText>
> <f:passThroughAttribute name="placeholder" value="Email"/>
> <f:passThroughAttribute name="autofocus" value="autofocus"/>
> <f:passThroughAttribute name="multiple" value="multiple"/>
> </h:inputText>
>
> What can we see here?
>
> I can't find a way to set the type to "email" (maybe I'm missing the
> solution). But it would be good that the spec handle the fact that if
> you write a pass trough attribute (like writting
> <f:passThroughAttribute name="type" value="email"/>) that collide with
> a generate one (<h:inputText> should have generated type="text"), the
> pass through override the generated one.
>
> In HTML5, my input is one line and auto-closed, in JSF, it's 5 lines,
> with an opening and a closing to the inputText. Seriously? I'm 100% in
> favor of supporting pass trough directly inside the JSF component. It
> will make the code less verbose, more readeable, more HTML5 like...
> just better. Something like:
>
> <h:inputText required="true" p:placeholder="Email"
> p:autofocus="autofocus" p:multiple="multiple" />
>
> Isn't that so much better? Honestly?
>
> And since we are at making life easier, you might see that lots of
> HTML5 attribute have the same name and value (autofocus, multiple,
> checked, disabled, readonly, ...). Wouldn't it be cool that if a pass
> through attribute has a name but no value, it takes it's name as value?
>
> <h:inputText p:autofocus p:multiple/> => <input type="text"
> autofocus="autofocus" multiple="multiple"/>
>
> <h:inputText>
> <f:passThroughAttribute name="autofocus" />
> <f:passThroughAttribute name="multiple" />
> </h:inputText>
>
> => <input type="text" autofocus="autofocus" multiple="multiple"/>
>
> One more for the road, I know most of the EG members didn't really
> like it, but it's on the same topic as previous: just making life
> easier for users so they enjoy coding with JSF instead of using it
> only because it's what they bosses want. JSON is the standard to pass
> data in the current web. Ignoring it would be a big mistake in my
> opinion (for what it worth). When you call a REST service, there is
> high chances it will give you JSON. When you want to quickly write a
> "key/value" map, JSON is awesome.
>
> Right know, by not supporting JSON inside <f:passThroughAttributes>
> you will only force people who need JSON support to create a parser
> that will convert a JSON array to a Java Map, and do the conversion in
> their backing beans. Not hard, just boring. Each time I found
> something not hard but boring, I think it should have been on the spec
> so everybody use the same parser and have a standard way to do the
> same stuff easily.
>
> Don't get me wrong, I'm a huge fan and user of JSF, I really like the
> work of the EG group. But when I saw the full discussion about pass
> through attributes with at least 3 good solutions
> (<f:passThroughAttribute(s)> tags, namespace to have them directly
> inside JSF component, JSON support) and that finally only the heavier
> will go on the spec, I can't prevent myself from asking : why?
>
> Regards,
>
> Paul.
Andy
On 6/20/12 3:00 PM, Edward Burns wrote:
> In light of the excellent discussion on this topic, here are the
> proposed spec changes for 1089-passThroughAttributes.
>
> ACTION: Please review this and give feedback by 12:00 EDT Friday. I
> really hope you all find it acceptable as is, though.
>
> SECTION: CHANGE UIComponent
>
> Remove constant UIComponent.DATA_ATTRIBUTES_KEY. Replace it with a
> read-only JavaBeans property "passThroughAttributes". Here's the spec.
>
> public abstract Map<String, Object> getPassThroughAttributes()
>
> This method must never return null. This Map is the data structure that
> holds passThrough attributes that must be rendered when the component is
> rendered. The ResponseWriter is responsible for ensuring these
> attributes are rendered correctly. The returned implementation must
> support all of the standard and optional Map methods, plus support the
> following additional requirements.
>
> The Map instance is backed by StateHolder and must participate in
> partial state saving, if that feature is enabled.
>
> The Map implementation must implement the java.io.Serializable
> interface.
>
> Any attempt to add a null key or value must throw a NullPointerException
>
> Any attempt to add a key that is not a String must throw a
> ClassCastException.
>
> SECTION: DELETE f:dataAttribute
>
> SECTION: CHANGE HTML_BASIC RenderKit overview section
>
> Delete the section titled "General notes regarding HTML5 support." The
> passThroughAttributes feature will be affected with changes on the
> ResponseWriter, not the RenderKit.
>
> SECTION: ADD f:attributes
>
> Add a new tag in the jsf_core taglibrary for facelets (not JSP). Here's
> the spec.
>
> For each Map.Entry in the Map<String, Object> referenced by the value
> attribute of this tag, take the following action. If
> Map.Entry.getValue() is a ValueExpression, call
> component.setValueExpression(Map.Entry.getKey(), Map.Entry.getValue()).
> Otherwise, call component.getAttributes().put(Map.Entry.getKey(),
> Map.Entry.getValue()).
>
> Attributes
>
> value an EL Expression that evaluates to a Map<String, Object>. The
> values may be String literals or ValueExpressions.
>
> SECTION: ADD f:passThroughAttribute
>
> Add a new tag in the jsf_core taglibrary for facelets (not JSP). Here's
> the spec.
>
> Add an attribute to the passThroughAttributes map of the UIComponent
> associated with the closest parent UIComponent.
>
> Attributes
>
> name The name of the passThrough attribute to be set.
>
> value The value of the passThrough attribute to be set. If the value is a
> ValueExpression, it must not be evaluated before storing in the map.
>
> SECTION: add f:passThroughAttributes
>
> Add a new tag in the jsf_core taglibrary for facelets (not JSP). Here's
> the spec.
>
> For each Map.Entry in the Map<String, Object> referenced by the value
> attribute of this tag, take the following action. Call
> component.getPassThroughAttributes().put(Map.Entry.getKey(),
> Map.Entry.getValue()).
>
> Attributes
>
> value The value of the passThrough attribute to be set. If the value is
> a ValueExpression, it must not be evaluated before storing in the map.
> The entries in this map are rendered as pass through attributes when the
> component is rendered. See ResponseWriter for how this happens.
>
> SECTION: NON-CHANGE
>
> While we all love how clever it feels to use namespaced attributes, I
> don't think it adds enough value. I'm not going to add it to the spec.
>
> SECTION: CHANGE ResponseWriter class javadocs.
>
> Add new section at the end of the existing class javadocs.
>
> Rendering Pass Through Attributes
>
> The set of attributes written for a component is determined by its
> Renderer. In addition to these "renderer specific" attributes, "pass
> through" attributes are also possible. Pass through attributes are
> contained in the Map returned by UIComponent.getPassThroughAttributes().
> If a UIComponent instance is passed to startElement(), the
> ResponseWriter must ensure that all pass through attributes on that
> component are rendered on the root markup element for that component.
> If there is a pass through attribute with the same name as a renderer
> specific attribute, the pass through attribute takes precedence. Pass
> through attributes are rendered with a call to writeURIAttribute().
>
> SECTION: CHANGE ResponseWriter.startElement() javadocs
>
> Add this text at the end of the existing text that describes the
> "component" parameter.
>
> This component is inspected for its pass through attributes as described
> in the class javadocs.
>
> SECTION: CHANGE VDLDocs and RenderKit docs
>
> Strike the term "pass through attribute" from the VDLDoc and RenderKit
> docs. In its place, use similar text that conveys the meaning without
> using the words "pass through"
>
> Ed
>