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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">That’s the appropriate work around at this point. Typically I’ll put a few things that I know will always be present at the end. For example the if the query
is triggered by a point query I prepend the x/y:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">'point':{<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 'epsg:26915': [[mapx], [mapy]],<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 'epsg:4326': [[maplon], [maplat]]<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> }<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I also tend to use the nodtata attribute of the resultset tag to output a null value for the object if it wasn’t found. That way each layer would *<b>always</b>*
be represented in the output. Our devs preferred checking for a null as opposed to checking if a property exists. Not sure what the proper convention is but it seems to work for us at the expense of slightly larger responses. Here’s an example from our service
we have:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">[resultset layer="ama" nodata=" 'ama':null,"][feature]<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 'ama':{<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 'name':'[item name="unit_name"]',<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 'id':'[item name="uniqueid" lc="true"]'<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> },[/feature][/resultset]<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">[resultset layer="sna" nodata=" 'sna':null,"][feature]<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 'sna':{<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 'name':'[item name="site_name"]',<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 'id':'[item name="bremcode" lc="true"]',<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 'url':'http://www.dnr.state.mn.us/snas/detail.html?id=[item name="bremcode" lc=true]'<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> },[/feature][/resultset]<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">If the ama and sna layers return no results you’d see:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">‘sna’:null,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">‘ama’:null,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">in the JSON response.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Oh, I believe any attribute in a template tag must use no quotes or double quotes, same goes for HTML legend templates since they use the same tag parser.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Steve<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> mapserver-users-bounces@lists.osgeo.org [mailto:mapserver-users-bounces@lists.osgeo.org]
<b>On Behalf Of </b>Richard Greenwood<br>
<b>Sent:</b> Tuesday, March 11, 2014 7:03 PM<br>
<b>To:</b> mapserver<br>
<b>Subject:</b> [mapserver-users] JSON template<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The JSON template has <b>[feature trimlast=","]</b> for a single layer that may return multiple records, but I don't see that functionality for the whole JSON object. For example if I have two layers but only one returns results I end up
with a trailing comma and invalid JSON.<br>
<br>
// MapServer template<br>
{<br>
[resultset layer=layer1]<br>
{<br>
[feature trimlast=","]<br>
{ ... }<br>
[/feature]<o:p></o:p></p>
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<p class="MsoNormal"> }, <span style="color:#38761D">// might need to trim this comma if layer below doesn't return result</span><o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"> [/resultset]<br>
<br>
[resultset layer=layer2]<br>
{<br>
[feature trimlast=","]<br>
{ ... }<br>
[/feature]<br>
} <span style="color:#38761D">// no comma here because we think it's last result object</span><br>
[/resultset]<br>
}<o:p></o:p></p>
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<p class="MsoNormal">I can work around it by putting a comma and empty object at the end:<br>
,{}<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">which is the way I've done it when writing JSON with standard templates, but that's sort of inconsistent with the [feature trimlast=","] option.<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Am I missing anything? Should I file a feature enhancement request?<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">And trimlast="," does seem to need to require double, not single quotes.<o:p></o:p></p>
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<p class="MsoNormal">Thanks,<br>
Rich<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><o:p> </o:p></p>
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<p class="MsoNormal">-- <br>
Richard Greenwood<br>
<a href="mailto:richard.greenwood@gmail.com">richard.greenwood@gmail.com</a><br>
<a href="http://www.greenwoodmap.com">www.greenwoodmap.com</a> <o:p></o:p></p>
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