Multipart Command Implementation

• Key: STR-2772
• Type: New Feature
• Status: Open
• Priority: Minor
• Assignee: Unassigned
• Reporter: Niall Pemberton
• Component/s: Core
• Affects Version/s: 1.3.0
• Fix Version/s: 1.4.x

Environment

Operating System: other
Platform: Other

Description

I'm proposing that the multipart processing be separated out into a set of
Commands in a separate chain:

  <!-- ========== Mulitpart Processing chain ========== -->
  <chain name="process-multipart">

      <!-- Check if the request is a multipart request -->
      <command className="o.a.s.c.c.servlet.CheckIfMultipartRequest"/>

      <!-- Create the multipart handler -->
      <command className="o.a.s.c.c.CreateMultipartHandler"/>

      <!-- Wrap the multipart request -->
      <command className="o.a.s.c.c.servlet.WrapMultipartRequest"/>

      <!-- See if the Struts Multipart Handler can process the request -->
      <command className="o.a.s.c.c.servlet.StrutsMultipartHandler"/>

  </chain>

The main "process-action" chain would be modified to use a LookupCommand that
ignores the result of this new "process-multipart" chain. This will allow
multiple multipart handlers to be added to the chain, with the one that
actually handles the request returning "true" to stop processing of
the "process-multipart" chain (but not "process-action" chain).

This proposal has a number of benefits:

1) All mutlipart handling is now in Commands which can easily be configured

2) Removed request "wrapping" code from ComposableRequestProcessor - no need to
sub-class ComposableRequestProcessor to modify the "wrapping".

3) RequestUtils's static populate() method is redundant - all that code is now
in commands - making custom multipart (and form population) processing much
easier.

4) Multiple multipart handlers can be easily configured by simply adding
additional commands to the multipart chain.