topic How do I parse JSON in a Share Component? in Alfresco Archive

How do I parse JSON in a Share Component?

bjornd — Thu, 08 Sep 2011 20:50:19 GMT

How do I access the Rhino JSON parser from webscript .js code that is part of a Share Component? Or access any other secure non-evaluating JSON parser for that matter.

Re: How do I parse JSON in a Share Component?

sonata82 — Fri, 09 Sep 2011 07:44:29 GMT

The only thing I found was using the JsonUtils from SpringSurf: http://www.springsurf.org/sites/1.0.0.M3/spring-webscripts/spring-webscripts-documentation/reference/html/js-index.html#js-index-jsonutils

Re: How do I parse JSON in a Share Component?

bjornd — Fri, 09 Sep 2011 19:44:57 GMT

The only thing I found was using the JsonUtils from SpringSurf: http://www.springsurf.org/sites/1.0.0.M3/spring-webscripts/spring-webscripts-documentation/reference/html/js-index.html#js-index-jsonutils

Thanks for the suggestion, but jsonUtils.toObject doesn't work in Alfresco, it produces instead "Expected collection or sequence. foo evaluated instead to freemarker.ext.beans.StringModel".

This is the logged error when the "Object" is received by freemarker.

If I use "eval()" instead, freemarker receives the intended object and everything works. But eval() is of course totally forbidden for the purposes of parsing JSON data in any serious project, so I was just wondering how everybody else deals with this?

Re: How do I parse JSON in a Share Component?

bjornd — Sat, 10 Sep 2011 15:38:15 GMT

The freemarker error message turned out to be a red herring. The object that was expected to be a JavaScript array was actually a Java object of the class org.json.JSONArray returned by jsonUtils.toObject. As documented, by the way, but still somewhat confusing. Java JSONArrays are not compatible with JavaScript arrays since element access is handled in a completely different way.

I solved my problem by including Douglas Crockford's public-domain parser in my code. I found it via the link at the bottom of the page http://www.json.org/js. This is how I use it:

var connector = remote.connect("alfresco");
var response = connector.get("/my/service/url");
var data = json_parse(response + "");‍‍‍

The response+"" thing on the last line converts the object returned by connector.get into a real JavaScript string. The original object is not a real JavaScript string, it lacks some of the standard string methods, which are used by the JSON parser.