org.apache.shindig.gadgets.features

Class FeatureRegistry

java.lang.Object

org.apache.shindig.gadgets.features.FeatureRegistry

Direct Known Subclasses:

TestFeatureRegistry

public class FeatureRegistry
extends Object

Mechanism for loading feature.xml files from a location keyed by a String. That String might be the location of a text file which in turn contains other feature file locations; a directory; or a feature.xml file itself.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FeatureRegistry.FeatureBundle
static class	FeatureRegistry.LookupResult

Field Summary

Fields

Modifier and Type	Field and Description
static String	CACHE_NAME
static com.google.common.base.Splitter	CRLF_SPLITTER
static String	FILE_SCHEME
static String	RESOURCE_SCHEME

Constructor Summary

Constructors

Constructor and Description
FeatureRegistry(FeatureResourceLoader resourceLoader, CacheProvider cacheProvider, List<String> features, FeatureFileSystem fileSystem) Construct a new FeatureRegistry, using resourceLoader to load actual resources, and loading data from the list of features provided, each of which points to a directory (whose .xml files will be scanned), file (interpreted as feature.xml), or resource (interpreted as feature.xml).
FeatureRegistry(FeatureResourceLoader resourceLoader, CacheProvider cacheProvider, List<String> features, FeatureFileSystem fileSystem, String repository)

Method Summary

Methods

Modifier and Type	Method and Description
Set<String>	getAllFeatureNames() Helper method, returns all known feature names.
FeatureRegistry.LookupResult	getAllFeatures() Returns all known FeatureResources in dependency order, as described in getFeatureResources.
FeatureRegistry.LookupResult	getFeatureResources(GadgetContext ctx, Collection<String> needed, List<String> unsupported) Helper method retrieving feature resources, including transitive dependencies.
FeatureRegistry.LookupResult	getFeatureResources(GadgetContext ctx, Collection<String> needed, List<String> unsupported, boolean transitive) For the given list of needed features, retrieves all the FeatureResource objects that contain their content and, if requested, that of their transitive dependencies.
List<String>	getFeatures(Collection<String> needed) Calculates and returns a dependency-ordered (as in getFeatureResources) list of features included directly or transitively from the specified list of needed features.
String	getRepository()
protected void	loadFeature(Uri parent, String xml, Map<String,org.apache.shindig.gadgets.features.FeatureRegistry.FeatureNode> featureMapBuilder) Method that loads gadget features.
protected String	makeCacheKey(Collection<String> needed, GadgetContext ctx, List<String> unsupported)
protected com.google.common.collect.ImmutableMap<String,org.apache.shindig.gadgets.features.FeatureRegistry.FeatureNode>	register(List<String> resourceList) Reads and registers all of the features in the directory, or the file, specified by the given resourceKey.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CACHE_NAME

public static final String CACHE_NAME

See Also:

Constant Field Values

RESOURCE_SCHEME

public static final String RESOURCE_SCHEME

See Also:

Constant Field Values

FILE_SCHEME

public static final String FILE_SCHEME

See Also:

Constant Field Values

CRLF_SPLITTER

public static final com.google.common.base.Splitter CRLF_SPLITTER

Constructor Detail

FeatureRegistry

@Inject
public FeatureRegistry(FeatureResourceLoader resourceLoader,
                      CacheProvider cacheProvider,
                      List<String> features,
                      FeatureFileSystem fileSystem)
                throws GadgetException

Construct a new FeatureRegistry, using resourceLoader to load actual resources, and loading data from the list of features provided, each of which points to a directory (whose .xml files will be scanned), file (interpreted as feature.xml), or resource (interpreted as feature.xml).

Parameters:

resourceLoader -

features -

Throws:

GadgetException

FeatureRegistry

public FeatureRegistry(FeatureResourceLoader resourceLoader,
               CacheProvider cacheProvider,
               List<String> features,
               FeatureFileSystem fileSystem,
               String repository)
                throws GadgetException

Throws:

GadgetException

Method Detail

getRepository

public String getRepository()

register

protected com.google.common.collect.ImmutableMap<String,org.apache.shindig.gadgets.features.FeatureRegistry.FeatureNode> register(List<String> resourceList)
                                                                                                                           throws GadgetException

Reads and registers all of the features in the directory, or the file, specified by the given resourceKey. Invalid features or invalid paths will yield a GadgetException. All features registered by this method must be valid (well-formed XML, resource references all return successfully), and each "batch" of registered features must be able to be assimilated into the current features tree in a valid fashion. That is, their dependencies must all be valid features as well, and the dependency tree must not contain circular dependencies.

Parameters:

resourceList - The files or directories to load the feature from. If feature.xml is passed in directly, it will be loaded as a single feature. If a directory is passed, any features in that directory (recursively) will be loaded. If res://*.txt or res:*.txt is passed, we will look for named resources in the text file. If path is prefixed with res:// or res:, the file is treated as a resource, and all references are assumed to be resources as well. Multiple locations may be specified by separating them with a comma.

Throws:

GadgetException - If any of the files can't be read, are malformed, or invalid.

getFeatureResources

public FeatureRegistry.LookupResult getFeatureResources(GadgetContext ctx,
                                               Collection<String> needed,
                                               List<String> unsupported,
                                               boolean transitive)

For the given list of needed features, retrieves all the FeatureResource objects that contain their content and, if requested, that of their transitive dependencies. Resources are returned in order of their place in the dependency tree, with "bottom"/ depended-on resources returned before those that depend on them. Resource objects within a given feature are returned in the order specified in their corresponding feature.xml file. In the case of a dependency tree "tie" eg. A depends on [B, C], B and C depend on D - resources are returned in the dependency order specified in feature.xml. Fills the "unsupported" list, if provided, with unknown features in the needed list.

Parameters:

ctx - Context for the request.

needed - List of all needed features.

unsupported - If non-null, a List populated with unknown features from the needed list.

Returns:

LookupResult object that may be used to render the needed features.

getFeatureResources

public FeatureRegistry.LookupResult getFeatureResources(GadgetContext ctx,
                                               Collection<String> needed,
                                               List<String> unsupported)

Helper method retrieving feature resources, including transitive dependencies.

Parameters:

ctx - Context for the request.

needed - List of all needed features.

unsupported - If non-null, a List populated with unknown features from the needed list.

Returns:

List of FeatureResources that may be used to render the needed features.

getAllFeatures

public FeatureRegistry.LookupResult getAllFeatures()

Returns all known FeatureResources in dependency order, as described in getFeatureResources. Returns only GADGET-context resources. This is a convenience method largely for calculating JS checksum.

Returns:

List of all known (RenderingContext.GADGET) FeatureResources.

getFeatures

public List<String> getFeatures(Collection<String> needed)

Calculates and returns a dependency-ordered (as in getFeatureResources) list of features included directly or transitively from the specified list of needed features. This API ignores any unknown features among the needed list.

Parameters:

needed - List of features for which to obtain an ordered dep list.

Returns:

Ordered list of feature names, as described.

getAllFeatureNames

public Set<String> getAllFeatureNames()

Helper method, returns all known feature names.

Returns:

All known feature names.

loadFeature

protected void loadFeature(Uri parent,
               String xml,
               Map<String,org.apache.shindig.gadgets.features.FeatureRegistry.FeatureNode> featureMapBuilder)
                    throws GadgetException

Method that loads gadget features.

Parameters:

parent - uri of parent

xml - xml to parse

Throws:

GadgetException

makeCacheKey

protected String makeCacheKey(Collection<String> needed,
                  GadgetContext ctx,
                  List<String> unsupported)