M7350/base/docs/html/guide/topics/manifest/provider-element.jd
2024-09-09 08:52:07 +00:00

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page.title=<provider>
@jd:body
<dl class="xml">
<dt>syntax:</dt>
<dd><pre class="stx">&lt;provider android:<a href="#auth">authorities</a>="<i>list</i>"
android:<a href="#enabled">enabled</a>=["true" | "false"]
android:<a href="#exported">exported</a>=["true" | "false"]
android:<a href="#gprmsn">grantUriPermissions</a>=["true" | "false"]
android:<a href="#icon">icon</a>="<i>drawable resource</i>"
android:<a href="#init">initOrder</a>="<i>integer</i>"
android:<a href="#label">label</a>="<i>string resource</i>"
android:<a href="#multi">multiprocess</a>=["true" | "false"]
android:<a href="#nm">name</a>="<i>string</i>"
android:<a href="#prmsn">permission</a>="<i>string</i>"
android:<a href="#proc">process</a>="<i>string</i>"
android:<a href="#rprmsn">readPermission</a>="<i>string</i>"
android:<a href="#sync">syncable</a>=["true" | "false"]
android:<a href="#wprmsn">writePermission</a>="<i>string</i>" &gt;
. . .
&lt;/provider&gt;</pre></dd>
<dt>contained in:</dt>
<dd><code><a href="{@docRoot}guide/topics/manifest/application-element.html">&lt;application&gt;</a></code></dd>
<dt>can contain:</dt>
<dd><code><a href="{@docRoot}guide/topics/manifest/meta-data-element.html">&lt;meta-data&gt;</a></code>
<br/><code><a href="{@docRoot}guide/topics/manifest/grant-uri-permission-element.html">&lt;grant-uri-permission&gt;</a></code></dd>
<dt>description:</dt>
<dd>Declares a content provider &mdash; a subclass of
{@link android.content.ContentProvider} &mdash; that supplies structured
access to data managed by the application. All content providers that
are part of the application must be represented by {@code &lt;provider&gt;}
elements in the manifest file. The system cannot see, and therefore will
not run, any that are not declared. (You need to declare only
those content providers that you develop as part of your application,
not those developed by others that your application uses.)
<p>
The Android system identifies content providers by the authority part
of a {@code content:} URI. For example, suppose that the following URI
is passed to <code>{@link android.content.ContentResolver#query
ContentResolver.query()}</code>:
<p style="margin-left: 2em">{@code content://com.example.project.healthcareprovider/nurses/rn}</p>
<p>
The {@code content:} scheme identifies the data as belonging to a content
provider and the authority ({@code com.example.project.healthcareprovider})
identifies the particular provider. The authority therefore must be unique.
Typically, as in this example, it's the fully qualified name of a
ContentProvider subclass. The path part of a URI may be used by a content
provider to identify particular data subsets, but those paths are not
declared in the manifest.
</p>
<p>
For information on using and developing content providers, see a separate document,
<a href="{@docRoot}guide/topics/providers/content-providers.html">Content Providers</a>.
</p></dd>
<dt>attributes:</dt>
<dd><dl class="attr">
<dt><a name="auth"></a>{@code android:authorities}</dt>
<dd>A list of one or more URI authorities that identify data under the purview
of the content provider.
Multiple authorities are listed by separating their names with a semicolon.
To avoid conflicts, authority names should use a Java-style naming convention
(such as {@code com.example.provider.cartoonprovider}). Typically, it's the name
of the ContentProvider subclass.
<p>
There is no default. At least one authority must be specified.
</p></dd>
<dt><a name="enabled"></a>{@code android:enabled}</dt>
<dd>Whether or not the content provider can be instantiated by the system &mdash;
"{@code true}" if it can be, and "{@code false}" if not. The default value
is "{@code true}".
<p>
The <code><a href="{@docRoot}guide/topics/manifest/application-element.html">&lt;application&gt;</a></code> element has its own
<code><a href="{@docRoot}guide/topics/manifest/application-element.html#enabled">enabled</a></code> attribute that applies to all
application components, including content providers. The
<code><a href="{@docRoot}guide/topics/manifest/application-element.html">&lt;application&gt;</a></code> and {@code &lt;provider&gt;}
attributes must both be "{@code true}" (as they both
are by default) for the content provider to be enabled. If either is
"{@code false}", the provider is disabled; it cannot be instantiated.
</p></dd>
<dt><a name="exported"></a>{@code android:exported}</dt>
<dd>Whether or not the content provider can be used by components of other
applications &mdash; "{@code true}" if it can be, and "{@code false}" if not.
If "{@code false}", the provider is available only to components of the
same application or applications with the same user ID. The default value
is "{@code true}".
<p>
You can export a content provider but still limit access to it with the
<code><a href="{@docRoot}guide/topics/manifest/provider-element.html#prmsn">permission</a></code> attribute.
</p></dd>
<dt><a name="gprmsn"></a>{@code android:grantUriPermissions}</dt>
<dd>Whether or not those who ordinarily would not have permission to
access the content provider's data can be granted permission to do so,
temporarily overcoming the restriction imposed by the
<code><a href="{@docRoot}guide/topics/manifest/provider-element.html#rprmsn">readPermission</a></code>,
<code><a href="{@docRoot}guide/topics/manifest/provider-element.html#wprmsn">writePermission</a></code>, and
<code><a href="{@docRoot}guide/topics/manifest/provider-element.html#prmsn">permission</a></code> attributes
&mdash;
"{@code true}" if permission can be granted, and "{@code false}" if not.
If "{@code true}", permission can be granted to any of the content
provider's data. If "{@code false}", permission can be granted only
to the data subsets listed in
<code><a href="{@docRoot}guide/topics/manifest/grant-uri-permission-element.html">&lt;grant-uri-permission&gt;</a></code> subelements,
if any. The default value is "{@code false}".
<p>
Granting permission is a way of giving an application component one-time
access to data protected by a permission. For example, when an e-mail
message contains an attachment, the mail application may call upon the
appropriate viewer to open it, even though the viewer doesn't have general
permission to look at all the content provider's data.
</p>
<p>
In such cases, permission is granted by
<code>{@link android.content.Intent#FLAG_GRANT_READ_URI_PERMISSION}</code>
and <code>{@link android.content.Intent#FLAG_GRANT_WRITE_URI_PERMISSION}</code>
flags in the Intent object that activates the component. For example, the
mail application might put {@code FLAG_GRANT_READ_URI_PERMISSION} in the
Intent passed to {@code Context.startActivity()}. The permission is specific
to the URI in the Intent.
</p>
<p>
If you enable this feature, either by setting this attribute to "{@code true}"
or by defining <code><a href="{@docRoot}guide/topics/manifest/grant-uri-permission-element.html">&lt;grant-uri-permission&gt;</a></code>
subelements, you must call
<code>{@link android.content.Context#revokeUriPermission
Context.revokeUriPermission()}</code> when a covered URI is deleted from
the provider.
</p>
<p>
See also the <code><a href="{@docRoot}guide/topics/manifest/grant-uri-permission-element.html">&lt;grant-uri-permission&gt;</a></code>
element.
</p></dd>
<dt><a name="icon"></a>{@code android:icon}</dt>
<dd>An icon representing the content provider.
This attribute must be set as a reference to a drawable resource containing
the image definition. If it is not set, the icon specified for the application
as a whole is used instead (see the <code><a href="{@docRoot}guide/topics/manifest/application-element.html">&lt;application&gt;</a></code>
element's <code><a href="{@docRoot}guide/topics/manifest/application-element.html#icon">icon</a></code> attribute).</dd>
<dt><a name="init"></a>{@code android:initOrder}</dt>
<dd>The order in which the content provider should be instantiated,
relative to other content providers hosted by the same process.
When there are dependencies among content providers, setting this
attribute for each of them ensures that they are created in the order
required by those dependencies. The value is a simple integer,
with higher numbers being initialized first.</dd>
<dt><a name="label"></a>{@code android:label}</dt>
<dd>A user-readable label for the content provided.
If this attribute is not set, the label set for the application as a whole is
used instead (see the <code><a href="{@docRoot}guide/topics/manifest/application-element.html">&lt;application&gt;</a></code> element's
<code><a href="{@docRoot}guide/topics/manifest/application-element.html#label">label</a></code> attribute).
<p>
The label should be set as a reference to a string resource, so that
it can be localized like other strings in the user interface.
However, as a convenience while you're developing the application,
it can also be set as a raw string.
</p></dd>
<dt><a name="multi"></a>{@code android:multiprocess}</dt>
<dd>Whether or not an instance of the content provider can be created in
every client process &mdash; "{@code true}" if instances can run in multiple
processes, and "{@code false}" if not. The default value is "{@code false}".
<p>
Normally, a content provider is instantiated in the process of the
application that defined it. However, if this flag is set to "{@code true}",
the system can create an instance in every process where there's a client
that wants to interact with it, thus avoiding the overhead of interprocess
communication.
</p></dd>
<dt><a name="nm"></a>{@code android:name}</dt>
<dd>The name of the class that implements the content provider, a subclass of
{@link android.content.ContentProvider}. This should be a fully qualified
class name (such as, "{@code com.example.project.TransportationProvider}").
However, as a shorthand, if the first character of the name is a period,
it is appended to the package name specified in the
<code><a href="{@docRoot}guide/topics/manifest/manifest-element.html">&lt;manifest&gt;</a></code> element.
<p>
There is no default. The name must be specified.
</p></dd>
<dt><a name="prmsn"></a>{@code android:permission}</dt>
<dd>The name of a permission that clients must have to read or write the
content provider's data. This attribute is a convenient way of setting a
single permission for both reading and writing. However, the
<code><a href="#rprmsn">readPermission</a></code> and
<code><a href="#wprmsn">writePermission</a></code> attributes take precedence
over this one. If the <code><a href="{@docRoot}guide/topics/manifest/provider-element.html#rprmsn">readPermission</a></code>
attribute is also set, it controls access for querying the content provider.
And if the <code><a href="#wprmsn">writePermission</a></code> attribute is set,
it controls access for modifying the provider's data.
<p>
For more information on permissions, see the
<a href="{@docRoot}guide/topics/manifest/manifest-intro.html#sectperm">Permissions</a>
section in the introduction and a separate document,
<a href="{@docRoot}guide/topics/security/security.html">Security and
Permissions</a>.
</p></dd>
<dt><a name="proc"></a>{@code android:process}</dt>
<dd>The name of the process in which the content provider should run. Normally,
all components of an application run in the default process created for the
application. It has the same name as the application package. The
<code><a href="{@docRoot}guide/topics/manifest/application-element.html">&lt;application&gt;</a></code> element's
<code><a href="{@docRoot}guide/topics/manifest/application-element.html#proc">process</a></code>
attribute can set a different
default for all components. But each component can override the default
with its own {@code process} attribute, allowing you to spread your
application across multiple processes.
<p>
If the name assigned to this attribute begins with a colon (':'), a new
process, private to the application, is created when it's needed and
the activity runs in that process.
If the process name begins with a lowercase character, the activity will run
in a global process of that name, provided that it has permission to do so.
This allows components in different applications to share a process, reducing
resource usage.
</p></dd>
<dt><a name="rprmsn"></a>{@code android:readPermission}</dt>
<dd>A permission that clients must have to query the content provider.
See also the <code><a href="#prmsn">permission</a></code> and
<code><a href="#wprmsn">writePermission</a></code> attributes.</dd>
<dt><a name="sync"></a>{@code android:syncable}</dt>
<dd>Whether or not the data under the content provider's control
is to be synchronized with data on a server &mdash; "{@code true}"
if it is to be synchronized, and "{@ code false}" if not.</dd>
<dt><a name="wprmsn"></a>{@code android:writePermission}</dt>
<dd>A permission that clients must have to make changes to the data
controlled by the content provider.
See also the <code><a href="#prmsn">permission</a></code> and
<code><a href="#rprmsn">readPermission</a></code> attributes.</dd>
</dl></dd>
<!-- ##api level indication## -->
<dt>introduced in:</dt>
<dd>API Level 1</dd>
<dt>see also:</dt>
<dd><a href="{@docRoot}guide/topics/providers/content-providers.html">Content Providers</a></dd>
</dl>