Documentation/Nightly/Developers/FAQ/Extensions

Extensions

What is the Extensions Index ?

This page has been moved to read-the-docs.

What is an API Key ?

See http://en.wikipedia.org/wiki/Application_programming_interface_key

How to obtain an API key to submit on the extension server ?

In order to upload extensions on the slicer extensions server, it is required to:

1. Create an account on the extension server: http://slicer.kitware.com by clicking on the Register link in the top right corner



This image shows the top portion of http://slicer.kitware.com after it has been expanded by clicking the Register button.

2. Go to NA-MIC community and click on Join community

3. Retrieve your API key looking at your account details:

   1. Go to http://slicer.kitware.com. If needed, signin by clicking on Login in the top right corner.
   2. Click on your name in the top right corner.
   3. Click on My account.
   4. Click on API tab.

   5. Copy the API Key associated with Default application.

      1. There is currently a bug preventing api key containing non alpanumeric characters from being used.
         If your Default api key contain for example a /, try to delete the api key and regenerate one that is not containing "/" and is named Default.
         We are working on the issue to update the build system so that it properly escape "/" and also get in touch with Midas team so that api key containing just number and letter are generated.

Is --launch flag available for a MacOSX installed Slicer.app ?

On MacOSx, running Slicer with the --help argument does NOT list the usual launcher related options.

$ ./Slicer.app/Contents/MacOS/Slicer --help
Usage
 Slicer [options]
 
 Options
   --, --ignore-rest                     Ignores the rest of the labeled arguments following this flag. (default: false)
   -h, --help                            Display available command line arguments.
   [...]
   --version                             Displays version information and exits.

To provide some background information, when generating the package that will be distributed, an application bundle Slicer.app is created. As explained here, a bundle is a directory with a standardized hierarchical structure that holds executable code and the resources used by that code. It means that since all libraries contained within a bundle are referenced relatively to the location of either the CLI or the Slicer executable, the use of launcher does NOT make sens.

To help fixing-up the libraries, executables and plugins so that they reference each other in a relative way, CMake provides us with the BundleUtilities module.

This module is used in two situations:

1. Fixup of Slicer application itself. See SlicerCPack.cmake#L36-68 and SlicerCPackBundleFixup.cmake.in
2. Fixup of an extension package. See SlicerExtensionCPack.cmake#L126-143 and SlicerExtensionCPackBundleFixup.cmake.in

What is the difference between Documentation/Nightly/Modules and Documentation/Nightly/Extensions ?

As suggested by the namespace names:

• All module documentation pages should be located under Documentation/Nightly/Modules
• All extension documentation pages should be located under Documentation/Nightly/Extensions

For example, if an an extension named DoSomethingGreat bundles three modules ModuleA, ModuleB and ModuleC. The following pages should be created:

• Documentation/Nightly/Extensions/DoSomethingGreat
• Documentation/Nightly/Modules/ModuleA
• Documentation/Nightly/Modules/ModuleB
• Documentation/Nightly/Modules/ModuleC

In case your extension bundles only one module, the extension name is expected to match the module name. For example, if your extension is named DoSomethingAwesome, the associated module is expected to be named DoSomethingAwesome. The following pages will then be created:

• Documentation/Nightly/Extensions/DoSomethingAwesome
• Documentation/Nightly/Modules/DoSomethingAwesome

where page Extensions/DoSomethingAwesome redirect to page Modules/DoSomethingAwesome.

To setup a redirection, simply add the following text to page Extensions/DoSomethingAwesome:

#REDIRECT [[Documentation/Nightly/Modules/DoSomethingAwesome]]

For an example, see here

More details about redirection are available here: http://www.mediawiki.org/wiki/Help:Redirects

Which URL should be associated with EXTENSION_HOMEPAGE metadata ?

Extensions available through the Slicer Extensions Catalog are expected to have a page created under the Nightly documentation namespace. The corresponding URL should be associated with the EXTENSION_HOMEPAGE metadata.

For example:

• set(EXTENSION_HOMEPAGE "http://slicer.org/slicerWiki/index.php/Documentation/Nightly/Extensions/DoSomethingGreat")
• set(EXTENSION_HOMEPAGE "http://slicer.org/slicerWiki/index.php/Documentation/Nightly/Extensions/DoSomethingAwesome")

Note that this also apply for extension bundling only one module. Indeed, in this case the page will redirect to the appropriate module page. For example: http://www.slicer.org/slicerWiki/index.php/Documentation/Nightly/Extensions/SkullStripper

How to rename an extension to add new features ?

If you created an extension to perform Task1, but later on, your module is getting more generic and you add some other tasks, the name of your extension might change. In order to rename, your extension, you should:

• Remove your old extension from the ExtensionsIndex
• Then, submit your extension again (including new features) with a new name