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 Resource modification hooks
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 <H2>
 Resource modification hooks</H2>
 <P >So far, we've assumed that resource API is being used to modify resources
 that are located in the user's file system.&nbsp; This is indeed the fundamental
 structure of the workspace, but it's also possible that a plug-in adds
 capabilities for manipulation of resources that are managed somewhere
 else.&nbsp; For example, the platform <a href="team.htm">Team support</a>
 plug-ins add the ability to work with resources that are under the management of
 a versioning repository.</P>

 <P > The resource API includes capabilities that have been added specifically
   to enable the team support plug-ins and plug-ins that implement repository providers
   using the team support.&nbsp; The following discussion covers the generic mechanism
   for registering resource hooks.&nbsp; See <a href="team_provider_repository.htm#hooks">Implementing
   a repository provider</a> for a discussion of how team uses these hooks.&nbsp;&nbsp;</P>

 <h3 >
 Resource move/delete hooks</h3>

 <P >
 This hook allows the team plug-in and its providers to control
     how resource moves and deletes are implemented.&nbsp; The hook includes the ability to prevent
 these operations from
     happening.&nbsp; Implementors can provide alternate implementations for
     moving or deleting files, folders, and projects.&nbsp;</P>

 <P >
 The team plug-in uses the <a href="../reference/extension-points/org_eclipse_core_resources_moveDeleteHook.html"><b>org.eclipse.core.resources.moveDeleteHook</b></a>
 extension point to register its hook:</P>

 <pre >&lt;extension point=&quot;org.eclipse.core.resources.moveDeleteHook&quot; id=&quot;MoveDeleteHook&quot;&gt;
 	&lt;moveDeleteHook class=&quot;org.eclipse.team.internal.core.MoveDeleteManager&quot;/&gt;
 &lt;/extension&gt;
 </pre>

 <P >
 The supplied class must implement <a href="../reference/api/org/eclipse/core/resources/team/IMoveDeleteHook.html"><b>IMoveDeleteHook</b></a>,
 which is called by the platform whenever a resource is moved or deleted.&nbsp;
 The team plug-in installs a move delete hook manager that can determine which
 team provider is managing a resource and invoke its specific hook.</P>

 <h3 >
 File modification validators</h3>

 <p>It's also possible that team repository providers will need to prevent or
 intervene in the editing or saving of a file. The team plug-in
 accomplishes this by using the extension point <a href="../reference/extension-points/org_eclipse_core_resources_fileModificationValidator.html"><b>org.eclipse.core.resources.fileModificationValidator</b></a>
 to register a validator that is called whenever a resource is to be modified.</p>

 <pre >&lt;extension point=&quot;org.eclipse.core.resources.fileModificationValidator&quot; id=&quot;FileValidator&quot;&gt;
 	&lt;fileModificationValidator class=&quot;org.eclipse.team.internal.core.FileModificationValidatorManager&quot;/&gt;
 &lt;/extension&gt;</pre>

 <P >The supplied class must implement <a href="../reference/api/org/eclipse/core/resources/team/FileModificationValidator.html"><b>FileModificationValidator</b></a>,
 which is called by the platform whenever a resource is saved or
 opened. The team plug-in installs a file modification manager that
 can determine which team provider is managing a resource and invoke its specific
 validator.</P>

 <h3 >General team hook</h3>
 <p>
 Repository providers sometimes need to hook into additional workspace operations
 in order to impose extra restrictions or customize workspace behavior.  The
 <a href="../reference/extension-points/org_eclipse_core_resources_teamHook.html"><b>org.eclipse.core.resources.teamHook</b></a>
 extension point provides some other special functions for team providers.  In particular,
 this hook allows a team provider to decide whether linked folders and files should
 be allowed for a given project.  Some repository systems have strict rules about the
 physical layout of projects on disk, and are not able to handle resources linked to
 arbitrary locations.</p>
 <p>
 The team hook also allows a repository provider to supply a
 <a href="runtime_jobs_rules.htm">scheduling rule</a>
 factory that will be used by all workspace operations.  Each time an API method is called
 that modifies the workspace in some way, a scheduling rule is obtained by the workspace.
 This scheduling rule prevents other threads from modifying those resources during
 the invocation of the API method.  If a repository provider is performing additional
 work inside a file modification validator or move/delete hook, the provider must
 also tell the workspace what additional scheduling rules it will need. See
 the section on <a href="resAdv_batching.htm">resource batching</a> for more
 details on how the workspace uses scheduling rules.
 </p>
 <P >The supplied class for the team hook must implement <a href="../reference/api/org/eclipse/core/resources/team/TeamHook.html"><b>TeamHook</b></a>.
 The team plug-in installs the single team hook that
 can determine which team provider is managing a resource and invoke its specific
 hook.</P>

 <blockquote>

   <P ><i>Note:&nbsp; All three of these team hooks are designed specifically
     for use by the team core plug-in.&nbsp; They are not intended for general use.&nbsp;
     Team providers should not install hooks using these extension points, but
     instead implement their hooks in their Repository Provider class.&nbsp;&nbsp;
     See <a href="team_provider_repository.htm#hooks">Team resource modification
     hooks</a> for more information about using these hooks.</i></P>

 </blockquote>


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	Resource modification hooks
	</TITLE>

	<link rel="stylesheet" type="text/css" HREF="../book.css">
	</HEAD>
	<body>
	<H2>
	Resource modification hooks</H2>
	<P >So far, we've assumed that resource API is being used to modify resources
	that are located in the user's file system.  This is indeed the fundamental
	structure of the workspace, but it's also possible that a plug-in adds
	capabilities for manipulation of resources that are managed somewhere
	else.  For example, the platform <a href="team.htm">Team support</a>
	plug-ins add the ability to work with resources that are under the management of
	a versioning repository.</P>

	<P > The resource API includes capabilities that have been added specifically
	to enable the team support plug-ins and plug-ins that implement repository providers
	using the team support.  The following discussion covers the generic mechanism
	for registering resource hooks.  See <a href="team_provider_repository.htm#hooks">Implementing
	a repository provider</a> for a discussion of how team uses these hooks.  </P>

	<h3 >
	Resource move/delete hooks</h3>

	<P >
	This hook allows the team plug-in and its providers to control
	how resource moves and deletes are implemented.  The hook includes the ability to prevent
	these operations from
	happening.  Implementors can provide alternate implementations for
	moving or deleting files, folders, and projects. </P>

	<P >
	The team plug-in uses the <a href="../reference/extension-points/org_eclipse_core_resources_moveDeleteHook.html"><b>org.eclipse.core.resources.moveDeleteHook</b></a>
	extension point to register its hook:</P>

	<pre ><extension point="org.eclipse.core.resources.moveDeleteHook" id="MoveDeleteHook">
	<moveDeleteHook class="org.eclipse.team.internal.core.MoveDeleteManager"/>
	</extension>
	</pre>

	<P >
	The supplied class must implement <a href="../reference/api/org/eclipse/core/resources/team/IMoveDeleteHook.html"><b>IMoveDeleteHook</b></a>,
	which is called by the platform whenever a resource is moved or deleted.
	The team plug-in installs a move delete hook manager that can determine which
	team provider is managing a resource and invoke its specific hook.</P>

	<h3 >
	File modification validators</h3>

	<p>It's also possible that team repository providers will need to prevent or
	intervene in the editing or saving of a file. The team plug-in
	accomplishes this by using the extension point <a href="../reference/extension-points/org_eclipse_core_resources_fileModificationValidator.html"><b>org.eclipse.core.resources.fileModificationValidator</b></a>
	to register a validator that is called whenever a resource is to be modified.</p>

	<pre ><extension point="org.eclipse.core.resources.fileModificationValidator" id="FileValidator">
	<fileModificationValidator class="org.eclipse.team.internal.core.FileModificationValidatorManager"/>
	</extension></pre>

	<P >The supplied class must implement <a href="../reference/api/org/eclipse/core/resources/team/FileModificationValidator.html"><b>FileModificationValidator</b></a>,
	which is called by the platform whenever a resource is saved or
	opened. The team plug-in installs a file modification manager that
	can determine which team provider is managing a resource and invoke its specific
	validator.</P>

	<h3 >General team hook</h3>
	<p>
	Repository providers sometimes need to hook into additional workspace operations
	in order to impose extra restrictions or customize workspace behavior. The
	<a href="../reference/extension-points/org_eclipse_core_resources_teamHook.html"><b>org.eclipse.core.resources.teamHook</b></a>
	extension point provides some other special functions for team providers. In particular,
	this hook allows a team provider to decide whether linked folders and files should
	be allowed for a given project. Some repository systems have strict rules about the
	physical layout of projects on disk, and are not able to handle resources linked to
	arbitrary locations.</p>
	<p>
	The team hook also allows a repository provider to supply a
	<a href="runtime_jobs_rules.htm">scheduling rule</a>
	factory that will be used by all workspace operations. Each time an API method is called
	that modifies the workspace in some way, a scheduling rule is obtained by the workspace.
	This scheduling rule prevents other threads from modifying those resources during
	the invocation of the API method. If a repository provider is performing additional
	work inside a file modification validator or move/delete hook, the provider must
	also tell the workspace what additional scheduling rules it will need. See
	the section on <a href="resAdv_batching.htm">resource batching</a> for more
	details on how the workspace uses scheduling rules.
	</p>
	<P >The supplied class for the team hook must implement <a href="../reference/api/org/eclipse/core/resources/team/TeamHook.html"><b>TeamHook</b></a>.
	The team plug-in installs the single team hook that
	can determine which team provider is managing a resource and invoke its specific
	hook.</P>

	<blockquote>

	<P ><i>Note:  All three of these team hooks are designed specifically
	for use by the team core plug-in.  They are not intended for general use.
	Team providers should not install hooks using these extension points, but
	instead implement their hooks in their Repository Provider class.
	See <a href="team_provider_repository.htm#hooks">Team resource modification
	hooks</a> for more information about using these hooks.</i></P>

	</blockquote>



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