gecko/rdf/base/nsIRDFService.idl

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2012-05-21 04:12:37 -07:00
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsISupports.idl"
#include "nsIRDFResource.idl"
#include "nsIRDFLiteral.idl"
#include "nsIRDFDataSource.idl"
/**
* The RDF service interface. This is a singleton object which should be
* obtained from the <code>nsServiceManager</code>.
*/
[scriptable, uuid(BFD05261-834C-11d2-8EAC-00805F29F370)]
interface nsIRDFService : nsISupports {
/**
* Construct an RDF resource from a single-byte URI. <code>nsIRDFService</code>
* caches resources that are in-use, so multiple calls to <code>GetResource()</code>
* for the same <code>uri</code> will return identical pointers. FindResource
* is used to find out whether there already exists a resource corresponding to that url.
*/
nsIRDFResource GetResource(in AUTF8String aURI);
/**
* Construct an RDF resource from a Unicode URI. This is provided
* as a convenience method, allowing automatic, in-line C++
* conversion from <code>nsString</code> objects. The <code>uri</code> will
* be converted to a single-byte representation internally.
*/
nsIRDFResource GetUnicodeResource(in AString aURI);
nsIRDFResource GetAnonymousResource();
/**
* Construct an RDF literal from a Unicode string.
*/
nsIRDFLiteral GetLiteral(in wstring aValue);
/**
* Construct an RDF literal from a PRTime.
*/
nsIRDFDate GetDateLiteral(in PRTime aValue);
/**
* Construct an RDF literal from an int.
*/
nsIRDFInt GetIntLiteral(in long aValue);
/**
* Construct an RDF literal from a data blob
*/
[noscript] nsIRDFBlob getBlobLiteral(in const_octet_ptr aValue, in long aLength);
boolean IsAnonymousResource(in nsIRDFResource aResource);
/**
* Registers a resource with the RDF system, making it unique w.r.t.
* GetResource.
*
* An implementation of nsIRDFResource should call this in its
* Init() method if it wishes the resource to be globally unique
* (which is usually the case).
*
* @note that the resource will <i>not</i> be ref-counted by the
* RDF service: the assumption is that the resource implementation
* will call nsIRDFService::UnregisterResource() when the last
* reference to the resource is released.
*
* @note that the nsIRDFService implementation may choose to
* maintain a reference to the resource's URI; therefore, the
* resource implementation should ensure that the resource's URI
* (accessible via nsIRDFResource::GetValue(const char* *aURI)) is
* valid before calling RegisterResource(). Furthermore, the
* resource implementation should ensure that this pointer
* <i>remains</i> valid for the lifetime of the resource. (The
* implementation of the resource cache in nsIRDFService uses the
* URI maintained "internally" in the resource as a key into the
* cache rather than copying the resource URI itself.)
*/
void RegisterResource(in nsIRDFResource aResource, in boolean aReplace);
/**
* Called to notify the resource manager that a resource is no
* longer in use. This method should only be called from the
* destructor of a "custom" resource implementation to notify the
* RDF service that the last reference to the resource has been
* released, so the resource is no longer valid.
*
* @note As mentioned in nsIRDFResourceFactory::CreateResource(),
* the RDF service will use the result of
* nsIRDFResource::GetValue() as a key into its cache. For this
* reason, you must always un-cache the resource <b>before</b>
* releasing the storage for the <code>const char*</code> URI.
*/
void UnregisterResource(in nsIRDFResource aResource);
/**
* Register a <i>named data source</i>. The RDF service will call
* <code>nsIRDFDataSource::GetURI()</code> to determine the URI under
* which to register the data source.
*
* @note that the data source will <i>not</i> be refcounted by the
* RDF service! The assumption is that an RDF data source
* registers with the service once it is initialized (via
* <code>nsIRDFDataSource::Init()</code>), and unregisters when the
* last reference to the data source is released.
*/
void RegisterDataSource(in nsIRDFDataSource aDataSource,
in boolean aReplace);
/**
* Unregister a <i>named data source</i>. The RDF service will call
* <code>nsIRDFDataSource::GetURI()</code> to determine the URI under which the
* data source was registered.
*/
void UnregisterDataSource(in nsIRDFDataSource aDataSource);
/**
* Get the <i>named data source</i> corresponding to the URI. If a data
* source has been registered via <code>RegisterDataSource()</code>, that
* data source will be returned.
*
* If no data source is currently
* registered for the specified URI, and a data source <i>constructor</i>
* function has been registered via <code>RegisterDatasourceConstructor()</code>,
* the RDF service will call the constructor to attempt to construct a
* new data source. If construction is successful, the data source will
* be initialized via <code>nsIRDFDataSource::Init()</code>.
*/
nsIRDFDataSource GetDataSource(in string aURI);
/**
* Same as GetDataSource, but if a remote/XML data source needs to be
* constructed, then this method will issue a <b>blocking</b> Refresh
* call on that data source.
*/
nsIRDFDataSource GetDataSourceBlocking(in string aURI);
};
%{C++
extern nsresult
NS_NewRDFService(nsIRDFService** result);
%}