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Orion/Documentation/Developer Guide/Simple plugin example
This page explains how to write a plugin for Orion. It's intended for developers who want to extend Orion's functionality.
Contents
What's a plugin?
A plugin is basically just an HTML file that knows how to connect to the Orion client. A plugin can be hosted on any web server. Plugins are written in HTML and JavaScript.
In order to be useful, a plugin should provide one or more services. When Orion needs a service contributed by a plugin, it loads the plugin inside an IFrame.
Orion currently supports a small set of extension points — service types that plugins can contribute to, in order to customize the client and add more functionality. These include:
- Adding more commands to the editor toolbar
- Adding more commands to the navigator view
- Adding content assist for new file types
- Adding syntax highlighting rules for new file types
What you need
Every plugin must include the following JavaScript libraries:
- OpenAjax: defined in OpenAjaxManagedHub-all.js
- Orion Provider API: defined in plugin.js
The easiest way to satisfy these is to get orion-plugin.js, which is a minified file that includes both of them. You can then copy-paste its contents into a <script> tag in your plugin, or load it externally like so:
<script src="orion-plugin.js" />
Writing the plugin
Let's make a plugin that adds a button to the toolbar of the Orion editor. When clicked, it will reverse the selected text in the editor. This is not a very useful feature, but it'll be a good introduction to the concepts involved.
Creating the plugin HTML file
- Create a new HTML file called reversePlugin.html with the following content:
<!DOCTYPE html> <html> <head> <meta charset="UTF-8" /> <title>Reverse Plugin</title> </head> <body></body> </html>
- What we have now isn't a plugin yet. It's just a bare-bones HTML file. The next step is to include the API we'll need to talk to Orion.
- Grab the orion-plugin.js file (see What you need) and put it in the same folder as reversePlugin.html. Then add this inside the <head> tags of the HTML file:
<script src="orion-plugin.js" />
- Next, we'll add some code that exposes a service to Orion. Add the following, again inside the <head> tags:
<script> window.onload = function() { var provider = new eclipse.PluginProvider(); var serviceImpl = { /* TODO */ }; var serviceProperties = { /* TODO */ }; provider.registerServiceProvider("editorAction", serviceImpl, serviceProperties); provider.connect(); } </script>
- At this point, we've got an honest-to-goodness Orion plugin, albeit one that doesn't do anything. Let's go over the various parts in detail:
- var provider = new eclipse.PluginProvider() — TODO
Optionally, an object giving metadata about the plugin can be provided as an argument to the constructor. - var serviceImpl — This object gives the implementation of our service, the part that will do the actual work.
When someone requests our service — for example, by calling getService() on a ServiceReference object — our plugin will be loaded into an IFrame, and our service becomes available for use. The function-typed properties of the serviceImpl object define the methods of our service that people can call. - var serviceProperties — Every service provider can supply properties, which is an object that holds metadata about the service provider. Orion stores these properties when a plugin is installed (?), and they can later be queried without causing the plugin to be loaded.
Properties are often used to filter out service providers that are irrelevant to a particular task. For example, if you're writing a service provider for content assist, you'd specify what file types your provider applies to in its properties. The content assist loader then only loads plugins that provide content assist for the particular file type being edited. This is important because plugin load can be an expensive operation, so we want to avoid doing it if possible. - provider.registerServiceProvider("editorAction", serviceImpl, serviceProperties); — TODO
- provider.connect(); — TODO
- var provider = new eclipse.PluginProvider() — TODO
- Now we'll fill in the serviceImpl and serviceProperties objects with the actual details of the service that our plugin will provide.
TODO
- Before continuing, make sure that reversePlugin.html looks like this:
<!DOCTYPE html> <html> <head> <meta charset="UTF-8" /> <title>Reverse Plugin</title> <script> window.onload = function() { var provider = new eclipse.PluginProvider(); var serviceImpl = { run: function(text) { return text.split("").reverse().join(""); } }; var serviceProperties = { name: "Reverse Text", key: ["e", true] }; provider.registerServiceProvider("editorAction", serviceImpl, serviceProperties); provider.connect(); } </script> </head> <body></body> </html>
Testing the plugin
First we need to host our plugin somewhere.
- If you have a personal web server available, you can copy reversePlugin.html and orion-plugin.js there.
- If you're using Orionhub, you can put the plugin in a new folder in your Orionhub workspace. Then create a Site Configuration in Orion that launches your folder. See Launching your project as a website.
- You can also use http://mamacdon.github.com/m6/reverse/reversePlugin.html
Once you've got a URL for reversePlugin, you can install it:
- Go to http://yourOrionServer/add-extension.html#http://yourPluginServer/reversePlugin.html.
- You'll be prompted to install the plugin. Click Yes.
Now let's try it out.
- In Orion, go to the navigator and create a new file called test.txt.
- Click on test.txt to open the editor.
- You'll see a new button on the editor toolbar:
Image - Select some text, click the button, and it should be reversed.
Examples
Here are some existing plugins we've written. View their source code to see how they work:
- http://orionhub.org/plugins/sampleCommandsPlugin.html
- Contributes several sample actions to the Orion navigator by using the fileCommands service type.
- http://orionhub.org/plugins/htmlSyntaxHighlightPlugin.html
- Contributes syntax highlighting support for HTML files by using the ISyntaxHighlight service type.
- http://bokowski.github.com/format-js.html
- Contributes a "Beautify JS" button to the editor toolbar by using the editorAction service type.
- http://mamacdon.github.com/m6/uglify/uglify-plugin.html
- Contributes an "Uglify JS" button to the editor toolbar byusing the editorAction service type.
See also
- Installing a plugin
- eclipse.PluginProvider JSdoc