Allow POST instead of GET in piwik.php

[anonymous-matomo-user]

The current Javascript and tagging allows Urls up to 2083 Bytes with IE6 and IE7. They can not GET longer Urls… Once piwik uses more variables to track customizable user / page /etc.- segmentation, this might become a problem.
Current implementations of professional tools have the same limitations in their Javascript and data collection server interfaces. What about generating an Iframe in the page, POSTing the data in that Iframe instead of just generating a pixel request?
The server script piwik.php can be changed easily to handle POST as well as GET, the Javascript implementation might be developed as an optional script.

[mattab]

This seems overkill; why would you need to track more than 2k urls? Plus the iframe solution is not really something we are ready to implement (not industry standard, more a hack).
plus POSTing data is meant to be an “action”, something the user clicked or validated.
Thanks for feedback anyway

[robocoder]

With the new piwik.js, we might consider using XmlHttpRequest (or IE equivalent ActiveX objects) — for Web 2.0 goodness — and JSON. This would permit more complex data for custom_vars and allow for non-image responses, eg server generated idvisitor.

[robocoder]

In [3231], fixes #5721, refs #1460 - add .setRequestMethod("POST") to piwik.js

Use cases:

• workaround GET request length limit
• workaround mod_security or .htaccess rules that block request containing "http"

Notes:

• subject to same origin policy

[robocoder]

In [3238], the XmlHttpRequest is now asynchronous.

[mattab]

See also #2321