[JS2-1194] Some Portlets which contain 'document.write()' js calls (e.g. GWT-based portlet) is not rendered at first after adding the portlet.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.2.1
• Fix Version/s: 2.2.2
• Assignee: Woonsan Ko
• Reporter: Woonsan Ko
• Created: 28/Apr/10 09:22
• Updated: 25/May/10 09:19
• Resolved: 25/May/10 09:19

Description

This issue has been known for long time for client-side rendering modules, so there were some solutions.
However, we don't have any solution in JetUI yet.
GWT based portlet application should contain a js file, "...nocache.js", which contains "document.write()" calls. This call causes the weird page status after adding the portlet.

By the way, the Jetspeed-2 Desktop had a solution for this problem like the following:

• It retrieves the portlet rendered content from the /portlet pipeline.
• It inspects the content whether the content has <script> tags.
• If it contains a script tag with src attribute, it retrieves the real source content.
• It inspects each code line and replaces with the following rules:
  a) Replace "addEventListener|attachEvent" by a custom JS2 code:
  /\b([a-z_A-Z$]\w*)\s*\.\s*(addEventListener|attachEvent)\s*(/
  ==> "jetspeed.postload_" + methodNm + "(" + nodeRef + "," + script.substr(match.index + match[0].length)
  b) Replace "document.write()" by a custom JS2 code:
  /\b(document\s*.\s*write(ln)?)\s*(/
  ==> "jetspeed.postload_docwrite(" + script.substr(match.index + match[0].length)
  c) Replace "location.href = ..." by a custom JS2 code:
  /(;\s|\s+)([a-z_A-Z$][\w.])\s\.\s*(URL\s*|(location\s*(\.\s*href\s*) {0,1}

  ))=\s*(("[^"]"|'[^']'|[^;])[^;]*)/
  ==> "jetspeed.setdoclocation(" + match[2] + ', "' + memberExpr + '", (' + match[6] + '))' + script.substr(match.index + match[0].length)

• References: PortletWindow.src.js and core.src.js, APA-5, JS2-1063.

However, the solution provided by JS2 desktop has some caveats:

• Looks too hacky.
• If the script uses a different variable name for document, the current code could not detect it. (GWT does this: l = document; )

By the way, we could recommend some best practices for portlet development instead of fixing this problem inside JS2:

• A Portlet should not use "document.write()" calls; Instead, it is recommended to use Portlet 2.0 head contribution where possible.
• A Portlet should not use "addEventListener|attachEvent" calls; Instead, it is recommended to use higher level frameworks such as YUI3.
• It is not recommended for a Portlet to use "location.href = ...;".

Anyway, I don't have a clear idea to solve this problem yet.