Concept

OpenOffice.org Developer's Guide

Extensions

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• Extension Manager

• Extension Repositories
• The Active Extension
• Updating Extensions
• Processing Extensions
• Packaging Notes For Bundled Extensions
• Deployment Items
• Installing Extensions for All or a Single User
• Extension Manager in OpenOffice.org
• unopkg
• Location of Installed Extensions
• Extension Layers

• Checklist for Writing Extensions
• File Format
• description.xml

• Description of XML Elements
• Localized XML Elements
• Example

• Display Name
• Icon
• Extension Description
• Extension Identifiers
• Extension Versions
• Target Platform
• Simple License
• Dependencies
• Publisher Information
• System Integration
• Online Update of Extensions

• Running Online - Update
• Concept
• Example Scenario for Providing Updates
• Migration of Update Information
• Description of the Update Information
• Description of Atom Feed
• Examples

• Options Dialog

• Creating the GUI of the Options Page
• Saving and Reading Data for the Options Page
• Defining the Usage of Options Pages

• Adding a Leaf to an Existing Node
• Adding Several Leaves
• Grouping of Leaves
• Adding Nodes
• Adding Several Nodes
• Absolute Position of Leaves
• Grouping of Nodes
• Assigning Nodes to Modules
• Defining a Module
• Absolute Position of Nodes

• The Options Dialog of the Extension Manager

• Help Content

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The actual download location of an update is contained in the update information which is typically a xml file which is hosted on a server. Every update information contains only information for exactly one extension. The most important information are the location of the update and the version of this extension.

The Extension Manager needs to get hold of the update information in order to decide if the respective extension is a valid update. For example, it only makes sense to take a version into account that is greater than the version of the already installed extension. The information where the update information is located is contained in the description.xml of each extension. In particular the children of the <update-information> element, contain URLs which reference the update information. The Extension Manager uses these URL to download the update information and later uses the information in the update information to download the respective extension.

In case that an extension does not contain a description.xml or the description.xml does not contain the <update-information> element, the Extension Manager uses a default location to get update information. This location is build-in, and is therefore determined by the publisher of OpenOffice.org. Currently this information is contained in the version.(ini|rc) of the the office installation.

Now the attentive reader may be wondering, because it was mentioned before that the update information only contain information for just one extension. How come that just one built-in URL can be used to get information for multiple extensions? The answer is that there is a way to bundle several update information in one piece of data. This is done by using an XML atom feed which can reference multiple update information. For example a feed could reference multiple update information, which refer all to an extension with the same Id but have different versions. It could also contain references to update information of distinct extensions (different Id). Then the Extensions Manager will pick out the information it needs.

Not only the built-in URL can reference an atom feed but also every extension.

Content on this page is licensed under the Public Documentation License (PDL).