View source for Documentation/4.3/FAQ/Extensions

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== What is an extension ? ==
{{:Documentation/{{documentation/version}}/Extensions/Description}}

== What is the extensions catalog ? ==
{{:Documentation/{{documentation/version}}/Extensions/Catalog}}

== Why there are no windows 32-bit extensions available ?==

* Win 32 has a very limited amount of memory available to an application. 
* Many registration and segmentation algorithms fail on that platform because they run out of memory, when used with state of large data.
* Some of these failures are just that, some can crash slicer. Even though the "real" failure is  caused by overextending the capabilities of the hardware (in a way the users fault), it appears to the user that Slicer does not work.
* If you search the archives of slicer-users there are several such complaints until we started to discourage people to use 32 bit.

Discussion: http://massmail.spl.harvard.edu/public-archives/slicer-users/2013/006703.html

== Should I install the nightly version to access to last extension updates ? ==

If the extension developers contributed updates for the current stable release, you don't have to install the nightly version of Slicer. You can simply update the extension. Consider reading [[#How_to_update_an_already_installed_extension.3F|How to update an already installed extension ?]].

On the other hand, if the extension developers stopped to maintain the version of their extension built against the stable release (so that we can use the latest feature that will be in the next Slicer release), downloading the nightly is the only way to get the latest version of the extension.

== How to update an already installed extension? ==

Assuming updates extensions are available for your version of Slicer, it is currently not possible without uninstalling the extension and re-installing it.

We are currently developing a mechanism allowing to either manually update or automatically suggest update. In the process of finalizing, reviewing and testing, the corresponding feature will be available in Slicer {{documentation/nextversion}}.

For more details, see [1][2] and [3]

[1] http://na-mic.org/Mantis/view.php?id=2089

[2] https://github.com/mwoehlke-kitware/Slicer/tree/REBASE-2089-update-extensions

[3] http://wiki.slicer.org/wiki/Documentation/Labs/ExtensionsFrameworkRoadmap

== How to manually install an extension ? ==

1) Get revision associated with your install or built Slicer. (Menu -> Help -> About)

2) Download extension matching your Slicer revision. Select operating system, bitness and enter revision on http://slicer.kitware.com/midas3/slicerappstore

3) Extract the archive (zip or tar.gz) in a folder. You should then have a folder like:

 /path/to/<slicer_revision>-<os>-<bitness>-<extension_name>-<extension_scm><extension_revision>-YYYY-MM-DD

containing folder like:

 lib/Slicer-X.Y/cli-modules
 lib/Slicer-X.Y/qt-loadable-modules
 lib/Slicer-X.Y/qt-scripted-modules

For more details: [[Documentation/{{documentation/version}}/Developers/DirectoryStructure]]

4) In the Module settings (Menu -> Edit -> Settings), add the path ending with <code>lib/Slicer-X.Y/{cli|qt-scripted|qt-loadable}-modules</code>