Adding JSON Capability to SPServices

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For quite a while, I’ve gotten requests to offer some sort of JSON conversion capability in SPServices. The requests have often been fairly non-specific, meaning that they haven’t mentioned a particular Web Service operation, like GetListItems or GetWeb. However, I think that most people want to be able to get convert the XML they get back from GetListItems to JSON. This would be useful because a lot of the other jQuery plugins out there want JSON to work with.

I’ve written the beginnings of a function I will include in the next release of SPServices, and I wanted to offer it up for suggestions and requests. I want this converter function, which I’ve called SPXmlToJson, to be generally useful within an SPServices context. I don’t want to build a general-purpose converter; there are quite a few good ones out there. Generally, the data returned from SharePoint’s SOAP Web Services operations is fairly “flat”. By “flat”, I mean that there isn’t a huge amount of nesting. For example, GetListItems (which I expect to be the main context for using this function) simple passes back a z:row element for each item in the list with all of the column values as attributes.

Here’s an example:

<GetListItemsResponse xmlns="http://schemas.microsoft.com/sharepoint/soap/">
<GetListItemsResult>
    <listitems xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:rs="urn:schemas-microsoft-com:rowset" xmlns:z="#RowsetSchema">
      <rs:data ItemCount="22">
        <z:row ows_DocIcon="gif" ows_FileSizeDisplay="21530" ows_LinkFilename="cascaded_multiselect.GIF" ows_Title="3" ows_Modified="2011-07-05 12:17:54" ows_Editor="3;#Marc D Anderson" ows_Edit="0" ows_TestColumn="bar" ows__ModerationStatus="3" ows__Level="255" ows_ID="58" ows_owshiddenversion="5" ows_UniqueId="58;#{DF636FD7-2B27-4826-9E44-33E1F68F7EC4}" ows_FSObjType="58;#0" ows_Created_x0020_Date="58;#2011-04-13 00:35:51" ows_ProgId="58;#" ows_FileLeafRef="58;#cascaded_multiselect.GIF" ows_CheckoutUser="3;#Marc D Anderson" ows_FileRef="58;#Intranet/cascaded_multiselect.GIF" ows_MetaInfo="58;#vti_parserversion:SR|12.0.0.6421 vti_lmt:SW|Thu, 22 Oct 2009 03:42:52 GMT Order:DW|5800.00000000000 TestColumn:SW|bar vti_author:SR|SERVER\\username vti_lastwidth:IX|641 vti_winfileattribs:SW|00000000 vti_modifiedby:SR|SERVER\\username ContentTypeId:SW|0x01010077FE74FF93862D419170F4A09DD0BBC5 vti_ct:SW|Thu, 22 Oct 2009 03:42:52 GMT vti_lat:SW|Wed, 13 Apr 2011 04:34:58 GMT ContentType:SW|Document vti_title:SW|3 vti_sourcecontrolmultiuserchkoutby:VR|FSERVER\\\\username vti_lastheight:IX|286 " ows_Last_x0020_Modified="58;#2011-07-05 13:10:22"></z:row>
        <z:row ows_DocIcon="rtf" ows_FileSizeDisplay="1322" ows_LinkFilename="ChatLog.rtf" ows_Title="4" ows_Modified="2011-07-05 12:17:55" ows_Editor="3;#Marc D Anderson" ows_Edit="0" ows_TestColumn="bar" ows__ModerationStatus="3" ows__Level="255" ows_ID="59" ows_owshiddenversion="5" ows_UniqueId="59;#{7C8C1F98-E56C-4B8C-9BFB-50A4948BDC7D}" ows_FSObjType="59;#0" ows_Created_x0020_Date="59;#2011-04-13 00:35:52" ows_ProgId="59;#" ows_FileLeafRef="59;#ChatLog.rtf" ows_CheckoutUser="3;#Marc D Anderson" ows_FileRef="59;#Intranet/ChatLog.rtf" ows_MetaInfo="59;#vti_parserversion:SR|12.0.0.6421 vti_lmt:SW|Mon, 11 Apr 2011 17:09:08 GMT Order:DW|5900.00000000000 ContentTypeId:SW|0x01010077FE74FF93862D419170F4A09DD0BBC5 vti_ct:SW|Mon, 11 Apr 2011 17:09:08 GMT vti_lat:SW|Wed, 13 Apr 2011 04:34:59 GMT ContentType:SW|Document TestColumn:SW|bar vti_sourcecontrolmultiuserchkoutby:VR|SERVER\\\\username vti_title:SW|4 vti_author:SR|SERVER\\username vti_winfileattribs:SW|00000000 vti_modifiedby:SR|SERVER\\username " ows_Last_x0020_Modified="59;#2011-07-05 13:10:22"></z:row>
      </rs:data>
    </listitems>
  </GetListItemsResult>
</GetListItemsResponse>

Once you get past the enclosing “wrapper”, it’s very flat data: just a single element per item. Most of the other operations return similar structures (thought there’s precious little consistency). What I am thinking of is having the SPXmlToJson function accept a flat nodeset, which it will convert and return a JSON object. This ought to provide a very basic conversion capability that I can build on over time, as needed.

Here’s the function as it stands, and I’ve also made it available on the SPServices site in the latest alpha for v0.7.1. Please let me know what you think. Will this be enough? If not, what other options would you like to have available? What other operations are you likely to use SPXmlToJson with? Try it out and let me know your ideas.

Thanks for Paul Tavares and others for the help and nudging to get me to this point.

// This function converts a nodeset to JSON
$.fn.SPServices.SPXmlToJson = function(options) {

  var opt = $.extend({}, {
  ns: ""    // A flat XML nodeset (as from GetListItems)
  }, options);

  var json = [];

  opt.ns.each(function() {
  var row = {};
  var rowAttrs = this.attributes;
  for (var e=0; e < rowAttrs.length; e++) {
    var thisNodeName = rowAttrs[e].name;
    var trimmedNodeName = thisNodeName.indexOf("ows_") !== -1 ? thisNodeName.substring(4) : thisNodeName;
    row[trimmedNodeName] = rowAttrs[e].value;
  }
  json.push(row);
  });
  return json;
}; // End $.fn.SPServices.SPXmlToJson