[Developers] cursors, limits, MJT and chocolates

Mon Jul 9 19:23:12 UTC 2007

> Extra Belgian chocolates if somebody has an example of using the
> cursor feature with MJT.

That's some good incentive. ;-)

Below is a crude example. Cursors aren't in the official MJT docs, so  
I discovered this method by looking at the mjt source. Some of the  
implementation details could change (and Nix please correct me if  
this is not the right way to do this).

Note the "mjt.if='q.result.length > 0'" in the "ready" block.  
Normally, "next_cursor" will be null if there are no more results to  
read, but there is currently a known bug that prevents this from  
working correctly. Getting an empty result is the only way to be sure  
you've reached the end.

I hope this helps,
Darin

-----------------------------------------------------------
(headers omitted for brevity)

<body onload="mjt.run()" style="display:none">

<div mjt.script="" mjt.strip="1">
   var query = {
     'id':null,
     'name':null,
     'type':'/music/artist',
     'limit':20
   }

   var query_args = {}
   if (mjt.urlquery.cursor != null) {
     // use the cursor returned in the previous result
     query_args.cursor = mjt.urlquery.cursor
   }
</div>

<div mjt.task="q">
   mjt.mqlread([query], query_args)
</div>

<div mjt.choose="q.state">
   <div mjt.when="ready">
     <div mjt.if="q.result.length > 0">
         <h4>music artists in freebase:</h4>
         <ul>
            <li mjt.for="artist in q.result">
              $artist.name
            </li>
         </ul>
         <a href="?cursor=$q.next_cursor">next --></a>
     </div>
     <div mjt.else="">
         end of result set
     </div>
   </div>
   <div mjt.when="wait">
       loading...
   </div>
   <div mjt.when="error">
     error:
     <div mjt.for="msg in q.messages">
       $msg.message
     </div>
   </div>
</div>
</body>