Re: DirectLink

Seems to me you could implement an MapArea component pretty easily.  Have it take a listener and all that ... just like an DirectLink.

Basically, you can get the right IEngineService from the IEngine.

You can get a Gesture from the service.

The Gesture will provide you with the URL.

  ----- Original Message ----- 
  From: David Solis 
  To: 'Tapestry Developer' 
  Sent: Thursday, December 05, 2002 1:27 PM
  Subject: [Tapestry-developer] DirectLink


  Hello,

   

  I've a page which contains an image map and each area has associated an action, in fact a direct action.

   

  The  implementation is:

   

  HTML

  <span jwcid="hiddenZone">

  <a jwcid="link">link</a>

  </span>

  <img jwcid="bottomImage" src="/images/bottom.jpeg" border=0 usemap="#buttons" width="426" height="258"/>

   

  <map name="buttons">

    <area shape="rect" coords="324,124,371,204" href="calculator?service=direct&context=Home/link&sp=Sclear" alt="Clear"/>

    <area shape="rect" coords="262,124,308,203" href="calculator?service=direct&context=Home/link&sp=Splus" alt="Plus"/>

    <area shape="rect" coords="325,79,370,112" href="calculator?service=direct&context=Home/link&sp=Snegate" alt="Negate"/>

    <area shape="rect" coords="324,33,368,67" href="calculator?service=direct&context=Home/link&sp=Sdivide" alt="Divide"/>

    <area shape="rect" coords="262,77,308,112" href="calculator?service=direct&context=Home/link&sp=Sminus" alt="Subtract"/>

    <area shape="rect" coords="261,34,308,66" href="calculator?service=direct&context=Home/link&sp=Stimes" alt="Times"/>

    <area shape="rect" coords="192,171,250,204" href="calculator?service=direct&context=Home/link&sp=Sequals" alt="Equals"/>

    <area shape="rect" coords="132,170,179,205" href="calculator?service=direct&context=Home/link&sp=Spoint" alt="Point"/>

  </map>

   

  Page

      <component id="hiddenZone" type="Conditional"/>

      <component id="link" type="DirectLink">

          <binding name="listener" expression='listeners.processButton'/>

      </component>

      <component id="bottomImage" type="Image">

          <binding name="image" expression='assets.bottomImage'/>

      </component>

      <context-asset name="bottomImage" path="/images/bottom.jpeg"/>

   

  I had to  declare a DirectLink even though it's invisible and I encoded the URL for each area by hand. From my point of view this is ugly and depends on Tapestry internals.

  We've a menu implemented with javascript and used the same technique to solve this.

  My concern is why the DirectLink is just for html links? - Yes, I know this is a silly question; I guess these cases probably are exceptions for many applications, however I'm wondering if there is a general method to deal with direct actions?

   

  Is there a better way to encode the href elements?

   

   

  Regards

   

  David