[optimization] add util method to escape/encode special charaters when redering JSON

[tunggad]

I have a template that renders JSON like following:

`import com.mongodb.DBObject;

`(  String msg, List<DBObject> dtdList )

{ "statusMsg" : "<span style="color: #ff0000;">${msg}</span>", // style=\"color: #ff0000;\" also does not work
  "dtdList" : "`tag _dtdList(dtdList)`" }

this JSON String is returned for a AJAX request to partial-updade two fragment of the page. The problem is, when this JSON String arrives at client side, jQuery can't parse/evaluate it to a proper JavaScript JSON object, because the values within "..." cantain special charaters (", \, etc.).

What i want to recommend is to add a util method for direct usage AND an option when invoking a tag which escape the special characters or HTML-encode the content so that the JSON String can be properly evaluated at client side.

As workaround for meanwhile i can write a util method by myself which does this job and give raw strings which i want to being HTML-encoded. But i will stuck, if i want to use template, because the render method will be called and it write the contents direct into stringbuilder, i dont get a chance to do some pre-processing before it gets written.

BTW: I was always doing this style of AJAX partical-update, when multiple page-fragments should be updated per AJAX. With Grails, i dont know, what for auto-magic the framework does underneath, but it always worked properly and i must not call escapse/encode explicitely. May be, because Grails has its own JSON builder, which handles all this job internally.

[branaway]

Can you use single quote for the style attribute? Can you show me what the acceptable raw string you'd like to see?

[branaway]

BTW, all method in the JavaExtension class is available in the news. It has a method named escapeJavaScript(). See if that is what you want.

{ 
"statusMsg" : "${escapeJavaScript("<span style=\"color: #ff0000;\">$[msg]$</span>")},   
}

[tunggad]

Hi Bing, you have right, normally, replacing all quotes by single quotes would be sufficient, if the content does not contain futher special character. But sometime you render a piece of content which is generated by lib like the following:

{ "statusMsg" : "<span style='color: #ff0000;'>successful saved</span>", "dtdList" : "    
<ul>
          <li>
      <h5 class="hideshowDTD {index:1}">playshop.commons.null</h5>
      <p id="json_1" class="hide">{ "_id" : { "$oid" : "4e009f816e25de6c4b22b4c6"} , "package" : "playshop.commons" ,      "class" : "General"}</p>
      <div class="align_right">
        <a href="#" class="loadDTD {index:1}">load</a> |
        <a href="#" class="hideshowDTD {index:1}">hide/show</a>
      </div>
    </li>
          <li>
      <h5 class="hideshowDTD {index:2}">playshop.commons.null</h5>
      <p id="json_2" class="hide">{ "_id" : { "$oid" : "4dff0f94214504366fa79660"} , "package" : "playshop.commons" ,  "class" : "Meta"}</p>
      <div class="align_right">
        <a href="#" class="loadDTD {index:2}">load</a> |
        <a href="#" class="hideshowDTD {index:2}">hide/show</a>
      </div>
    </li>
      </ul>" }

You see the JSON String whin the <p> elements? They are not handcoded by me, they are MongoDB documents, and serialized in JSON by Mongo Lib, i want to show them as text on UI. But i have no control over whether quote or single quote should be used.

I will try escapeJavaScript() right now, is it only available in newest version of Japid? But apart from this method we still have the problem when we want to invoke tag/template right?

[branaway]

The method is there from day one, since it's part of Play's own library, JavaExtensions. For tags, I guess you'll need to fix the problem in the tag itself. If you're using local method as opposed to tag, then the escapeJavaScript() can be used as well.

[tunggad]

ok, for the meantime we must satisfy ourself with consequent using of single quotes and manual escaping of special character. But i wish a comfortable and sotisphicated solution, like Grails JSON builder.

Using single quotes lead to other error, which i will report in next ticket.