InstallVersion Object

This is an archived page. It's not actively maintained.

Parts of this page show the use of the XPInstall API. The majority of this API is now deprecated and as of Gecko 1.9 no longer available. Extension, Theme, and plug-in developers must switch away from install.js based packages to the new packaging scheme with an install.rdf manifest. In particular plugin developers should see how to package a plugin as an extension.


You use InstallVersion objects to contain version information for software.


This object and its methods are used both when triggering a download, to see whether a particular version needs to be installed, and when installing the software.

The init() method associates a particular version with an InstallVersion object, the toString() method converts versions in various formats to a string, and the compareTo() method compares these string and indicates the relationship between the two versions. Each of the version parameters is also available as a separate property of the InstallVersion object.