Jqgrid & progressive enhancement: Successfully progresses from HTML, to local JSON, to remote JSON, but pager doesn't start correctly?

Question

Take a look at what happens in my fiddle here: http://jsfiddle.net/tbH5H/

I'm trying to achieve proper progressive enhancement using jgrid. Everything works great, except I don't know how to give jqgrid the correct pager information on first load. My server side script dumps the JSON and a corresponding HTML table for SEO bots. But how can I also give the correct total page count to jqgrid on this first local load? The pager works correctly after a remote data pull as you can see in the fiddle.

HTML

<table id="grid">
    <tr><th>ID</th><th>State</th></tr>
    <tr><td>1</td><td>Alaska</td></tr>
    <!-- etc...server side script dumps this out for SEO... -->
</table>
<div id="pager"></div>  

JS

$("#grid").jqGrid({
    datatype:'local',
    // Server side script dumps this JSON out for first load only, 
    // other requests will come from remote source, see further down...
    data: [{"id":1,"state":"Alabama"},
           {"id":2,"state":"Alaska"},
           {"id":3,"state":"Arizona"},
           {"id":4,"state":"Arkansas"},
           {"id":5,"state":"California"},
           {"id":6,"state":"Colorado"},
           {"id":7,"state":"Connecticut"},
           {"id":8,"state":"Delaware"},
           {"id":9,"state":"Florida"},
           {"id":10,"state":"Georgia"}],  
    height: 250,
    width: 450,
    rowNum:10,
    colNames:['ID','State'],
    colModel:[
       {name:'id',    index:'id',    width:50},
       {name:'state', index:'state', width:100}
    ],
    caption: "States of the USA",
    pager: '#pager'
});
$("#grid").jqGrid('navGrid', '#pager',{edit: false, add: false, del: false, search: false, refresh: true});         

   // Convert the grid to read remotely, but don't trigger a unnecessary reload...
   // (because queries are expensive! We shouldn't need to run them twice!)
   $('#grid').jqGrid("setGridParam",{datatype:"json", mtype:"POST", url:"/some/url/here"});
   $('#grid').jqGrid("setGridParam",{postData:data});

Eleusis

Why do you need to to dump the first load? That doesn't look correct to me. Why can't everything be server side? – Percolate

How will google know about the data if everything is immediately processed through ajax? – Eleusis

Answer 1

Got it!

I needed to use localReader. See new fiddle: http://jsfiddle.net/2UCk6/

localReader: {
    // These values would be inserted on first page load from server-side script
    page: function(obj) { return 1; },
    total: function(obj) { return 5; }, 
    records: function(obj) { return 50; }
},

Eleusis

Answer 2

Your data should be in the following format:

{ 
  "total": "xxx", 
  "page": "yyy", 
  "records": "zzz",
  "rows" : [{"id":1,"state":"Alabama"},
       {"id":2,"state":"Alaska"},
       {"id":3,"state":"Arizona"},
       {"id":4,"state":"Arkansas"},
       {"id":5,"state":"California"},
       {"id":6,"state":"Colorado"},
       {"id":7,"state":"Connecticut"},
       {"id":8,"state":"Delaware"},
       {"id":9,"state":"Florida"},
       {"id":10,"state":"Georgia"}]
}

Where:

total   =  total pages for the query
page    = current page of the query
records = total number of records for the query
rows    = an array that contains the actual data

You need to have the json reader configured for the above some thing like given below:

 jsonReader : {
     root: "rows",
     page: "page",
     total: "total",
     records: "records",
     repeatitems: false,
     cell: "cell",
     ...
   },
...

More information can be found here with examples - http://www.trirand.com/jqgridwiki/doku.php?id=wiki:retrieving_data

Update

You can't have the feature when the datatype is local. When the data type is local the page/record etc are ignored by Jqgird. You should probably try virtual scrolling -> Go to Jqgrid Demo -> New in 3.7 -> Virtual Scrolling.

Or probably you should do a server call and return with the data you intend to use as local with the page/records etc?

Percolate

Here's an updated fiddle showing you that these adjustments don't seem to work: jsfiddle.net/NJ2nr/3 Any ideas? – Eleusis

@DavidGraham - Updated the answer, does that make sense? – Percolate

I'm getting close here: jsfiddle.net/NJ2nr/6 You have to click "run" first. – Eleusis

@DavidGraham I updated the jsfiddle, now the records came back. jsfiddle.net/NJ2nr/9 – Percolate

hmmmm...ok...this might work. Let me test this in my app. Be back in a few minutes and I can accept your answer. See! Never give up! :-) – Eleusis

seems to only work on jsfiddle, after pressing run. Can't get it to work in my own application...still working on it... – Eleusis

It looks like that when setting datatype to "json" the grid makes an initial ajax call. So your fiddle hasn't solved the problem. :-( – Eleusis