michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsISupports.idl"
michael@0: #include "nsIRDFResource.idl"
michael@0: #include "nsIRDFLiteral.idl"
michael@0: #include "nsIRDFDataSource.idl"
michael@0: 
michael@0: 
michael@0: /**
michael@0:  * The RDF service interface. This is a singleton object which should be
michael@0:  * obtained from the <code>nsServiceManager</code>.
michael@0:  */
michael@0: [scriptable, uuid(BFD05261-834C-11d2-8EAC-00805F29F370)]
michael@0: interface nsIRDFService : nsISupports {
michael@0:     /**
michael@0:      * Construct an RDF resource from a single-byte URI. <code>nsIRDFService</code>
michael@0:      * caches resources that are in-use, so multiple calls to <code>GetResource()</code>
michael@0:      * for the same <code>uri</code> will return identical pointers. FindResource
michael@0:      * is used to find out whether there already exists a resource corresponding to that url.
michael@0:      */
michael@0:     nsIRDFResource GetResource(in AUTF8String aURI);
michael@0: 
michael@0:     /**
michael@0:      * Construct an RDF resource from a Unicode URI. This is provided
michael@0:      * as a convenience method, allowing automatic, in-line C++
michael@0:      * conversion from <code>nsString</code> objects. The <code>uri</code> will
michael@0:      * be converted to a single-byte representation internally.
michael@0:      */
michael@0:     nsIRDFResource GetUnicodeResource(in AString aURI);
michael@0: 
michael@0:     nsIRDFResource GetAnonymousResource();
michael@0: 
michael@0:     /**
michael@0:      * Construct an RDF literal from a Unicode string.
michael@0:      */
michael@0:     nsIRDFLiteral  GetLiteral(in wstring aValue);
michael@0: 
michael@0:     /**
michael@0:      * Construct an RDF literal from a PRTime.
michael@0:      */
michael@0:     nsIRDFDate     GetDateLiteral(in PRTime aValue);
michael@0: 
michael@0:     /**
michael@0:      * Construct an RDF literal from an int.
michael@0:      */
michael@0:     nsIRDFInt      GetIntLiteral(in long aValue);
michael@0: 
michael@0:     /**
michael@0:      * Construct an RDF literal from a data blob
michael@0:      */
michael@0:     [noscript] nsIRDFBlob getBlobLiteral(in const_octet_ptr aValue, in long aLength);
michael@0: 
michael@0:     boolean IsAnonymousResource(in nsIRDFResource aResource);
michael@0: 
michael@0:     /**
michael@0:      * Registers a resource with the RDF system, making it unique w.r.t.
michael@0:      * GetResource.
michael@0:      *
michael@0:      * An implementation of nsIRDFResource should call this in its
michael@0:      * Init() method if it wishes the resource to be globally unique
michael@0:      * (which is usually the case).
michael@0:      *
michael@0:      * @note that the resource will <i>not</i> be ref-counted by the
michael@0:      * RDF service: the assumption is that the resource implementation
michael@0:      * will call nsIRDFService::UnregisterResource() when the last
michael@0:      * reference to the resource is released.
michael@0:      *
michael@0:      * @note that the nsIRDFService implementation may choose to
michael@0:      * maintain a reference to the resource's URI; therefore, the
michael@0:      * resource implementation should ensure that the resource's URI
michael@0:      * (accessible via nsIRDFResource::GetValue(const char* *aURI)) is
michael@0:      * valid before calling RegisterResource(). Furthermore, the
michael@0:      * resource implementation should ensure that this pointer
michael@0:      * <i>remains</i> valid for the lifetime of the resource. (The
michael@0:      * implementation of the resource cache in nsIRDFService uses the
michael@0:      * URI maintained "internally" in the resource as a key into the
michael@0:      * cache rather than copying the resource URI itself.)
michael@0:      */
michael@0:     void RegisterResource(in nsIRDFResource aResource, in boolean aReplace);
michael@0: 
michael@0:     /**
michael@0:      * Called to notify the resource manager that a resource is no
michael@0:      * longer in use. This method should only be called from the
michael@0:      * destructor of a "custom" resource implementation to notify the
michael@0:      * RDF service that the last reference to the resource has been
michael@0:      * released, so the resource is no longer valid.
michael@0:      *
michael@0:      * @note As mentioned in nsIRDFResourceFactory::CreateResource(),
michael@0:      * the RDF service will use the result of
michael@0:      * nsIRDFResource::GetValue() as a key into its cache. For this
michael@0:      * reason, you must always un-cache the resource <b>before</b>
michael@0:      * releasing the storage for the <code>const char*</code> URI.
michael@0:      */
michael@0:     void UnregisterResource(in nsIRDFResource aResource);
michael@0: 
michael@0:     /**
michael@0:      * Register a <i>named data source</i>. The RDF service will call
michael@0:      * <code>nsIRDFDataSource::GetURI()</code> to determine the URI under
michael@0:      * which to register the data source.
michael@0:      *
michael@0:      * @note that the data source will <i>not</i> be refcounted by the
michael@0:      * RDF service! The assumption is that an RDF data source
michael@0:      * registers with the service once it is initialized (via
michael@0:      * <code>nsIRDFDataSource::Init()</code>), and unregisters when the
michael@0:      * last reference to the data source is released.
michael@0:      */
michael@0:     void RegisterDataSource(in nsIRDFDataSource aDataSource,
michael@0:                             in boolean          aReplace);
michael@0: 
michael@0:     /**
michael@0:      * Unregister a <i>named data source</i>. The RDF service will call
michael@0:      * <code>nsIRDFDataSource::GetURI()</code> to determine the URI under which the
michael@0:      * data source was registered.
michael@0:      */
michael@0:     void UnregisterDataSource(in nsIRDFDataSource aDataSource);
michael@0: 
michael@0:     /**
michael@0:      * Get the <i>named data source</i> corresponding to the URI. If a data
michael@0:      * source has been registered via <code>RegisterDataSource()</code>, that
michael@0:      * data source will be returned.
michael@0:      *
michael@0:      * If no data source is currently
michael@0:      * registered for the specified URI, and a data source <i>constructor</i>
michael@0:      * function has been registered via <code>RegisterDatasourceConstructor()</code>,
michael@0:      * the RDF service will call the constructor to attempt to construct a
michael@0:      * new data source. If construction is successful, the data source will
michael@0:      * be initialized via <code>nsIRDFDataSource::Init()</code>.
michael@0:      */
michael@0:     nsIRDFDataSource GetDataSource(in string aURI);
michael@0: 
michael@0:     /**
michael@0:      * Same as GetDataSource, but if a remote/XML data source needs to be
michael@0:      * constructed, then this method will issue a <b>blocking</b> Refresh
michael@0:      * call on that data source.
michael@0:      */
michael@0:     nsIRDFDataSource GetDataSourceBlocking(in string aURI);
michael@0: };
michael@0: 
michael@0: %{C++
michael@0: extern nsresult
michael@0: NS_NewRDFService(nsIRDFService** result);
michael@0: %}
michael@0: