This server will be upgraded at 3pm Sydney time on December 3rd (December 2nd, 8pm PST) and will be down for up to 30 minutes.
This documentation relates to the latest version of Confluence.
If you are using an earlier version, please go to the documentation home page and select the relevant version.

Component Plugins

Added by Mike Cannon-Brookes, last edited by Sarah Maddox on Nov 03, 2008  (view change)
All Versions
Click for all versions
Confluence 2.10 Documentation

Index
Component plugin modules are available in Confluence 1.4 and later

Component plugin modules enable you to add components to Confluence's internal component system (powered by Spring).

Component Plugin Module

Each component module adds a single object to Confluence's component management system.

Other plugins and objects within Confluence can then be autowired with your component. This is very useful for having a single component that is automatically passed to all of your other plugin modules (ie a Manager object).

Here is an example atlassian-plugin.xml file containing a single component module:

<atlassian-plugin name="Sample Component" key="confluence.extra.component">
    ...
    <component name="Keyed Test Component" 
        key="testComponent" 
        alias="bogusComponent"
        class="com.atlassian.confluence.plugin.descriptor.BogusComponent" />
    ...
</atlassian-plugin>
  • the name attribute represents how this component will be referred to in the interface.
  • the key attribute represents the internal, system name for your component.
  • the class attribute represents the class of the component to be created
  • the alias attribute represents the alias this component will be stored with. This element is optional, if not specified the module key will be used instead.

Accessing Your Components

Accessing your components is extremely simple.

Autowired Objects

If your object is being autowired (for example another plugin module or an XWork action), the easiest way to access a component is to add a basic Java setter method.

For example, if you use the above BogusComponent module your object would retrieve the component as follows:

public void setBogusComponent(BogusComponent bogusComponent)
{
    this.bogusComponent = bogusComponent;
}

Non-autowired Objects

If your object is not being autowired, you may need to retrieve the component explicitly. This is done via the ContainerManager like so:

BogusComponent bc = (BogusComponent) ContainerManager.getComponent("bogusComponent");

Notes

Some issues to be aware of when developing a component:

  • One component module can depend on another component module but be careful of circular references (ie A requires B, B requires A).
  • The component "namespace" is flat at the moment, so choose a sensible alias for your component.
Enter labels to add to this page:
Please wait 
Looking for a label? Just start typing.

Comments (6)

 

  1. Dec 06, 2005

    David Peterson [CustomWare] says:

    Another note would be that component modules do not unload correctly if they are...

    Another note would be that component modules do not unload correctly if they are in a plugin which is uploaded rather than being put into WEB-INF/lib. The plugin can be uploaded, but the web server will have to be restarted regardless, making it kind of pointless uploading it in the first place.

    See CONF-4014 to track this issue.

    1. Feb 15, 2006

      Dan Hardiker says:

      If you disable the plugin before uninstalling it, and then enabled it after inst...

      If you disable the plugin before uninstalling it, and then enabled it after installing it again it all works ok.

      Atlassian have been made aware of the issue and where it is likely to lie.

      1. Feb 15, 2006

        David Peterson [CustomWare] says:

        Nice find! Looking forward to this one being fixed.

        Nice find! Looking forward to this one being fixed.

  2. Feb 01, 2008

    Anonymous says:

    Looking forward to this fix -jake  dual action cleanse

    Looking forward to this fix

    -jake 

    dual action cleanse

  3. Feb 14, 2008

    Anonymous says:

    What is the scope for these components? On first glance they appear to have app...

    What is the scope for these components? On first glance they appear to have application scope.
    -m

    1. Feb 14, 2008

      David Peterson [CustomWare] says:

      I believe that is the case, however if you try to access a component published i...

      I believe that is the case, however if you try to access a component published in one plugin from a different plugin it won't work because the second plugin cannot access classes defined in the first plugin.

      Personally, I don't use components at all any more, partly for this reason. For singletons I use standard static classes and methods. If I need to communicate between plugins it gets trickier, but I have a couple of libraries to help there too. Contact me if you have to do that.

Add Comment