Using Policy Files

Policy files allow a user to configure which version of a feature to update to when checking for updates.

Creating the Policy File

A sample policy file is shown below:

<update-policy>
  <url-map pattern="feature.id" url="http://hostname/update/nightly/site.xml"/>
</update-policy>

In this example, we save this to an XML file named "policy.xml". This is then placed next to the corresponding update site.xml. This effectively says "when I see feature with id x, instead go to update site y rather than the default". You can also use wildcards, such as feature.id.* if you have multiple features with the same prefix.

Using the Policy File

1. In Eclipse, navigate to Window > Preferences > Install/Update, and paste in the URL to the policy file (such as http://hostname/update/nightly/policy.xml).
2. Select "OK"
3. The next time you search for updates, it should use the new URL specified in the policy file.

An additional thought is to provide a preference page to allow the end user to choose which "release stream" they wish to subscribe to. In this case, there is a radio button that might specify "stable", "rc" and "nightly". Selecting one of these radio buttons would automatically set the policy file behind the scenes.