Equinox/p2/Discovery

Description

The purpose of the P2 Discovery mechanism is to provide a simplified and branded front-end for the P2 provisioning platform. Discovery can be used as a

• tool, to display and install from existing P2 repositories
• tool, to display and install from catalogs that point to P2 repositories
• framework, to build branded installer UIs

Branded presentation of a P2 repository

In this mode discovery acts as an alternative front-end to the P2 install UI without advanced features such as update site selection, grouping etc. All displayed meta-data comes from a single P2 repository. This is mainly useful for providing a UI for installing and updating extensions in RCP applications where all relevant features and meta-data are available from a single repository.

Catalog presentation of several P2 repositories with custom meta-data

In this mode discovery displays a catalog of items that point to an installable feature and P2 repository where that feature is available. This supports installing extensions where the the displayed meta-data is potentially different from what is presented in the P2 repository and has more details that are relevant at install time (e.g. price, screenshot, update sites).

Existing Implementations

• Mylyn Connector Discovery: Catalog presentation of Mylyn task repository connectors.

• Subversive SVN Team Provider Connector Discovery: Catalog presentation of Subversive extensions.

• Eclipse Marketplace Client: Custom catalog that is accessed through a web service.

Getting Discovery

Binaries

The Equinox P2 Discovery feature is available from the Helios and platform update sites:

• http://download.eclipse.org/releases/staging/
• http://download.eclipse.org/eclipse/updates/3.6milestones/

Sources

Sources are in the P2 CVS repository: Instructions for getting started

• org.eclipse.equinox.p2.discovery: Core data model.
• org.eclipse.equinox.p2.discovery.compatibility: Support for extension-point based catalogs.
• org.eclipse.equinox.p2.tests.discovery: Tests.
• org.eclipse.equinox.p2.ui.discovery: Discovery commands, wizard and viewer. P2 integration.

Integrating Discovery

• Displaying a P2 repository:

Catalog catalog = new Catalog();
catalog.setEnvironment(DiscoveryCore.createEnvironment());
catalog.setVerifyUpdateSiteAvailability(false);

// add strategy for retrieving remote catalog
RepositoryDiscoveryStrategy strategy = new RepositoryDiscoveryStrategy();
strategy.addLocation(new URI("http://location/of/p2/repo"));
catalog.getDiscoveryStrategies().add(strategy);

CatalogConfiguration configuration = new CatalogConfiguration();
configuration.setShowTagFilter(false);

DiscoveryWizard wizard = new DiscoveryWizard(catalog, configuration);
WizardDialog dialog = new WizardDialog(WorkbenchUtil.getShell(), wizard);
dialog.open();

• Displaying a directory:

Catalog catalog = new Catalog();
catalog.setEnvironment(DiscoveryCore.createEnvironment());
catalog.setVerifyUpdateSiteAvailability(false);

// look for descriptors from installed bundles
catalog.getDiscoveryStrategies().add(new BundleDiscoveryStrategy());

// look for remote descriptor
RemoteBundleDiscoveryStrategy remoteDiscoveryStrategy = new RemoteBundleDiscoveryStrategy();
remoteDiscoveryStrategy.setDirectoryUrl("http://location/of/directory.xml");
catalog.getDiscoveryStrategies().add(remoteDiscoveryStrategy);

CatalogConfiguration configuration = new CatalogConfiguration();
configuration.setShowTagFilter(false);

DiscoveryWizard wizard = new DiscoveryWizard(catalog, configuration);
WizardDialog dialog = new WizardDialog(WorkbenchUtil.getShell(), wizard);
dialog.open();

Extending Discovery

All discovery classes are in internal packages and marked as x-internal. Still discovery is designed with extensibility in mind and integrators are encouraged to provide feedback.

The discovery core is designed to allow clients to implement custom strategies for populating catalogs.

AbstractDiscoveryStrategy: Base class for implementing strategies that populate catalogs. Reference implementations are RemoteBundleDiscoveryStrategy (extension point based catalog) and RepositoryDiscoveryStrategy (P2 repository based catalog).

The UI is composed of extensible components.

DiscoveryWizard: Provides a wizard based workflow for installing extensions that embeds CatalogViewer in a wizard page.

CatalogViewer: A list based viewer with custom controls for displaying and installing catalog items.

Plan

Discovery will be shipped as part of Helios. The first version is expected for Helios M6.

All discovery bugs

• bug 301475: [publisher] Integrate branding icon in the metadata