eclipse_newsletter/2013/september/content/en_article4.php - gerrit/www.eclipse.org/community - Git at Google

 <?php
 /*******************************************************************************
  * Copyright (c) 2015 Eclipse Foundation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *    Eric Poirier (Eclipse Foundation) - Initial implementation
  *******************************************************************************/
 ?>


 <h1 class="article-title"><?php echo $pageTitle; ?></h1>

   <p>With the arrival of the Kepler release it’s time for a fresh look
     at the how the latest Eclipse tooling makes contributing to Eclipse
     easier and more fun than ever. Read on for a step-by-step guide how
     to setup a workspace for contributing changes to Eclipse using Git,
     Gerrit and Hudson.</p>

   <h2>Registering an Eclipse.org Account</h2>
   <p>Before we can get started we need to create an account on
     Eclipse.org.</p>
   <ol>
     <li><a href="https://dev.eclipse.org/site_login/createaccount.php">Register
         an account on Eclipse.org</a>
     <ul>
       <li>This account is used to access the Eclipse web properties such
         as the Wiki, Bugzilla as well as the code review system Gerrit.
         In order to contribute source code we need to review and sign
         the <a href="http://www.eclipse.org/legal/CLA.php">Eclipse.org
           Contributor License Agreement</a> and setup our account in
         Gerrit.
       </li>
     </ul></li>
     <li>Login to the <a
       href="https://dev.eclipse.org/site_login/?takemeback=https://projects.eclipse.org/user/login/sso">Eclipse
         projects forge</a> and complete the Contributor License
       Agreement
     </li>
     <li>Login to Gerrit and <a
       href="https://git.eclipse.org/r/login/settings/http-password">define
         a username</a></li>
     <li><a href="https://git.eclipse.org/r/login/settings/ssh-keys">Upload
         your public ssh-key</a> to Gerrit for authentication</li>
   </ol>

   <h2>Installing the Tools</h2>
   <p>
     All the tools we need are conveniently available as part of the <a
       href="http://www.eclipse.org/downloads/packages/eclipse-rcp-and-rap-developers/keplerr">Eclipse
       Kepler RCP and RAP Developers package</a>. We can also install the
     tools from their respective p2 repositories into any Eclipse
     instance using Install New Software from the Help menu:
   </p>
   <ul>
     <li><a href="http://eclipse.org/egit/">EGit</a> p2 repository -
       http://download.eclipse.org/egit/updates
     <ul>
       <li>Eclipse Git Team Provider</li>
       <li>Task Focused Interface for Eclipse Git Team Provider</li>
     </ul></li>
     <li><a href="http://eclipse.org/mylyn/">Mylyn</a> p2 repository -
       http://download.eclipse.org/mylyn/latest
     <ul>
       <li>Mylyn Tasks Connector: Bugzilla</li>
       <li>Mylyn Context Connector: Eclipse IDE</li>
       <li>Mylyn Builds Connector: Hudson/Jenkins</li>
       <li>Mylyn Reviews Connector: Gerrit</li>
       <li>Mylyn Version Connector: Git</li>
     </ul></li>
   </ul>

   <p>Some projects release frequently so installing directly from the
     project repositories has the benefit of getting the latest version.
     This tutorial is based on Mylyn 3.9.1 (Kepler SR1) which is
     available from the repository above.</p>

   <h2>Overview</h2>
   <p>Throughout the tutorial we’ll follow the typical steps for
     submitting a contribution to Eclipse.org. We’ll be using the Mylyn
     project as an example but the process is similar for most Eclipse
     projects:</p>
   <ol>
     <li>Querying the Eclipse.org Bugzilla for tasks</li>
     <li>Activating a Bugzilla task</li>
     <li>Committing and pushing a change to Git</li>
     <li>Monitoring the triggered build on Hudson</li>
     <li>Completing the resulting Gerrit code review</li>
   </ol>
   <p>We can complete the entire process from within the Eclipse IDE
     using the Eclipse tools provided by the Eclipse platform, EGit and
     Mylyn.</p>

   <h2>Querying Bugzilla</h2>
   <p>
     As a first step, we will look for a task in Bugzilla to work on. All
     Eclipse project use Bugzilla to track defects and requests for
     enhancements so it’s a good place to start. To make tasks from
     Bugzilla available in Eclipse we open the <i>Task List</i> view
     which is provided by Mylyn and right click to select <i>New > Query</i>
     from the context menu. The Eclipse.org Bugzilla repository is
     already pre-configured so we can select it and advance to the next
     page where we choose <i>Create query using form</i>. On the form
     page we enter a title and select <i>Mylyn Tasks</i> under <i>Product</i>
     and enter <i>helpwanted</i> under <i>Keywords</i>. <br /> <img
       src="/community/eclipse_newsletter/2013/september/images/septarticle4.1.png"
       alt="edit query" /><br />
     <br />


   <p>
     Queries are a personalized view of Bugzilla. They bring tasks we are
     interested in into the IDE and enable us to work with them. The
     query we created adds all tasks for the Mylyn Tasks project to the <i>Task
       List</i> that have been flagged by committers indicating that help
     from the community is desired. For this tutorial, we choose <a
       href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=325673">bug
       325673</a> which is about changing the default summary when
     creating new tasks with Mylyn but we could have picked any open
     task. We double click the task in the task list which opens a rich
     editor where we can review the description, comments, attachments
     and other details.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.2.png"
     alt="edit query" width="600" />
   <br />
   <br />

   <p>
     It’s good practice to state intention on a bug before starting to
     work on it to make others aware of our activity. In order to submit
     tasks we have to enter our account credentials by clicking the <i>Eclipse.org</i>
     link in the header of the Task Editor.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.3.png"
     alt="bugzilla repository settings" />
   <br />
   <br />

   <p>
     We can then refresh the task in the editor by clicking the <i>Synchronize
       Incoming Changes</i> button in the editor toolbar on the top
     right, enter a comment and submit our change.
   </p>

   <h2>Getting Source Code</h2>
   <p>Before we can start working on the task that we selected we need to
     get the source code. The Mylyn Tasks source code is hosted in a Git
     repository and managed by Gerrit.


   <p>
     To connect to the Eclipse.org Gerrit server we go back to the <i>Task
       List</i> and create another query for code reviews. We right click
     and select <i>New > Query</i> again. This time we have to use <i>Add
       Task Repository</i> and select <i>Gerrit Code Review</i> from the
     list. The server drop-down offers <i>Eclipse.org Reviews</i> as a
     template or we can enter <a
       href="https://git.eclipse.org/r/#/q/status:open,n,z">https://git.eclipse.org/r</a>
     as the server location. We also need to uncheck <i>Anonymous</i> and
     enter our Eclipse.org credentials.
   </p>
   <br />
   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.4.png"
     alt="gerrit repository settings" />
   <br />
   <br />

   <p>
     Back in the query dialog we enter a title and leave the default <i>My
       changes</i> selected. The query in the <i>Task List</i> will bring
     in our code reviews. If we haven’t submitted any code reviews, yet,
     it will remain empty initially.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.5.png"
     alt="query parameters" />
   <br />
   <br />

   <p>
     The next step is to import source code from Gerrit. Under <i>File >
       Import</i> we select <i>Projects from Git</i> and select <i>Gerrit</i>
     from the list on the next page. The selection page shows all Git
     repositories hosted on the Eclipse.org Gerrit instance. Since we
     want to contribute a change to Mylyn Tasks we select the <i>mylyn/org.eclipse.mylyn.tasks</i>
     repository.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.6.png"
     alt="source git repository" />
   <br />
   <br />

   <p>
     We can leave the defaults on the next pages and continue through the
     wizard. The repository is automatically cloned and we can select all
     projects to import on the last page. If an error is displayed that
     the SSH key is invalid or missing it needs to be generated first in
     the Eclipse preferences under <i>General > Network Connections >
       SSH2</i> and uploaded to Gerrit as described at the start of the
     tutorial.
   </p>

   <p>
     Once all projects have been imported we can get rid of the API
     baseline errors by opening the Eclipse preferences and selecting the
     <i>Plug-in Development > API Baselines</i> page and setting <i>Missing
       API baseline</i> to <i>Ignore</i>.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.7.png"
     alt="query parameters" />
   <br />
   <br />

   <h2>Working on Tasks</h2>
   <p>Back to our task at hand. We open the task in the task editor and
     use the blue ball button in the top left of the Task Editor to
     activate the task. Activating indicates that we are now working on
     the task.</p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.8.png"
     alt="new task" />
   <br />
   <br />

   <p>
     The features of Mylyn’s task-focused interface are beyond the scope
     of this tutorial. In short, as we edit code and navigate the source
     code Mylyn monitors interactions and builds a degree-of-interest
     model for the active task. We can now focus views such as the <i>Package
       Explorer</i> using the <i>Focus on Active Task</i> button from a
     view’s toolbar. Based on our interactions, focusing filters all
     elements that are not relevant to the task at hand dramatically
     reducing information overload and distraction. We can always go back
     to seeing everything by de-selecting the focus button in the
     toolbar.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.9.png"
     alt="package explorer" />
   <br />
   <br />

   <p>
     Assuming that we have made the necessary code changes for the task
     we are working on and verified our changes locally we are ready to
     commit to the Git repository. Right clicking and selecting <i>Team >
       Commit</i> on a file brings up the commit dialog where we can
     provide a message describing the change. By default this is
     populated with the bug ID, summary and task URL of the active task.
     This automatically enables traceability between the task and change
     in the version control system.
   </p>

   <p>
     The commit dialog has an option to automatically generate a <i>Change-Id</i>
     which is used by Gerrit to track the change. If we want to update
     the commit later Gerrit can relate the changes based on the change
     ID. We can leave the default which is replaced by a generated,
     unique ID as soon we commit.
   </p>

   <p>
     Another important setting in the dialog is the <i>Add Signed-off</i>
     by toolbar button that adds another header to the commit message.
     The <i>Signed-off-by</i> header confirms that we are acting in
     agreement with the <a href="http://www.eclipse.org/legal/CLA.php">terms
       of the Eclipse.org CLA</a> and enables committers to later accept
     our contribution.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.10.png"
     alt="commit changes to git repository" />
   <br />
   <br />

   <p>
     Once we select <i>Commit</i> and <i>Push</i> the change is committed
     to our local clone of the Git repository and then pushed to the
     remote Git repository which in our case is a Gerrit server.
   </p>

   <p>
     When importing repositories from Gerrit the Eclipse Git integration
     creates a configuration that pushes to <i>refs/for/master</i>. This
     is a special location defined by Gerrit that causes every change to
     be staged in a new branch for verification and code reviewed before
     it is merged into the master branch.
   </p>

   <h2>Monitoring Builds</h2>
   <p>The Mylyn Tasks project has configured a job on a Hudson server
     that runs as code reviews are created or updated in Gerrit. Every
     time a new branch is detected a build is automatically triggered to
     verify the change. As soon as the builds completes Hudson comments
     and votes on the code review.</p>

   <p>
     To view Hudson build results in Eclipse we have to add the
     Eclipse.org Hudson server first. Typing <i>Builds</i> into <i>Quick
       Access</i> in the main toolbar opens the Builds view.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.11.png"
     alt="builds" />
   <br />
   <br />

   <p>
     We use the <i>New Builds Server</i> button in the toolbar and select
     Hudson from the list of server types. On the next page we enter the
     URL of the Hudson server <a
       href="https://hudson.eclipse.org/sandbox/">https://hudson.eclipse.org/hudson/</a>
     and <i>Refresh</i>.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.12.png"
     alt="build server properties" />
   <br />
   <br />

   <p>
     The selected build plans are now shown in the <i>Builds</i> view and
     we can monitor the results in the <i>Builds</i> view without
     switching to the browser.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.13.png"
     alt="builds" />
   <br />
   <br />

   <h2>Getting Feedback</h2>

   <p>
     We now go back to the <i>Task List</i> and use the <i>Synchronize
       Changed</i> button in the toolbar to make the code review we just
     created visible in Eclipse. A little popup notification is displayed
     and the review is decorated with a blue arrow indicating that it has
     changes that we haven’t yet looked at. Opening the code review
     displays a rich editor similar to the <i>Task Editor</i> for
     Bugzilla. We can review the changes, called patch sets, and the
     review comments.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.14.png"
     alt="review comments" />
   <br />
   <br />

   <p>When we refresh the code review editor we notice that the review
     has received one vote already. The +1 in the Verified category is
     from Hudson indicating that the all tests passed. Now we need one or
     more people to review and approve the actual code change. Anyone who
     has an Eclipse.org account can participate in code reviews and cast
     their votes but in order to pass the code review a +2 is required.
     On Eclipse.org only committers or the respective project have the
     right to vote +2.</p>

   <p>
     We can explicitly add people in the <i>Code Reviewers</i> section if
     we know their Eclipse.org account ID or we can wait for someone to
     pick up the change. Committers are expected to monitor code reviews
     for their project and should respond within a few days. If nobody
     reacts to the code review it sometimes help to post the URL of the
     code review on the corresponding Bugzilla task explicitly asking for
     a review.
   </p>

   <p>While this workflow is described from the perspective of a
     contributor it’s important to know that committers would follow the
     exact same workflow and post their changes to Gerrit so other
     committers or members from the community can provide feedback before
     a change is merged.</p>

   <h2>Reviewing Code</h2>

   <p>
     The first step to review the code in the IDE is to open the code
     review from the <i>Task List</i>. The content under review is listed
     in the <i>Patch Sets</i> section. Each patch set corresponds to one
     commit on the Gerrit server and is tracked in a separate Git branch.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.15.png"
     alt="patch sets" />
   <br />
   <br />

   <p>
     Double clicking a file from a patch set opens an editor that shows
     the base revision on the left and the proposed changes on the right.
     Comments are added by selecting any line, right clicking and
     selecting <i>Add Comment</i>. Initially, comments are saved as
     drafts and are not visible to others.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.16.png"
     alt="comment" />
   <br />
   <br />

   <p>
     After we have added comments we need to vote on the overall change
     and publish comments to make them visible to everyone. To do that we
     select <i>Publish</i> from the review editor which open a dialog.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.17.png"
     alt="publish comment" />
   <br />
   <br />

   <p>
     The <i>IP Clean</i> flag indicates that all requirements of the
     Eclipse IP process such as a valid CLA and copyright headers in
     changed files have been met. Only committers can set that flag. The
     same applies to the <i>Code Review</i> category. Only project
     committers have permission to vote +2 and submit the review as a
     last step.
   </p>

   <img
     src="/community/eclipse_newsletter/2013/september/images/septarticle4.18.png"
     alt="review merge" />
   <br />
   <br />

   <p>Once a review is submitted by a committer, the most recent patch
     set on the review is merged into the master branch by Gerrit. This
     completes the contribution cycle and the new feature is now part of
     Mylyn.</p>

   <h2>Further Reading</h2>
   <ul>
     <li><a href="http://wiki.eclipse.org/Mylyn/Contributor_Reference">Mylyn
         Contributor Reference</a></li>
   </ul>

 <div class="bottomitem">
   <h3>About the Authors</h3>

   <div class="row">
     <div class="col-sm-12">
       <div class="row">
         <div class="col-sm-8">
           <img class="author-picture"
         src="/community/eclipse_newsletter/2013/september/images/steffen75.jpg"
         alt="Steffen Pingel" />
         </div>
         <div class="col-sm-16">
           <p class="author-name">
         Steffen Pingel<br />
         <a target="_blank" href="http://www.tasktop.com/">Tasktop</a>
       </p>
       <ul class="author-link">
         <li><a target="_blank"
           href="http://tasktop.com/blog/author/steffenpingel">Blog</a></li>
         <li><a target="_blank" href="https://twitter.com/steffen_pingel">Twitter</a></li>
       </ul>
         </div>
       </div>
     </div>
   </div>
 </div>

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	<?php
	/*******************************************************************************
	* Copyright (c) 2015 Eclipse Foundation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* Eric Poirier (Eclipse Foundation) - Initial implementation
	*******************************************************************************/
	?>


	<h1 class="article-title"><?php echo $pageTitle; ?></h1>

	<p>With the arrival of the Kepler release it’s time for a fresh look
	at the how the latest Eclipse tooling makes contributing to Eclipse
	easier and more fun than ever. Read on for a step-by-step guide how
	to setup a workspace for contributing changes to Eclipse using Git,
	Gerrit and Hudson.</p>

	<h2>Registering an Eclipse.org Account</h2>
	<p>Before we can get started we need to create an account on
	Eclipse.org.</p>
	<ol>
	<li><a href="https://dev.eclipse.org/site_login/createaccount.php">Register
	an account on Eclipse.org</a>
	<ul>
	<li>This account is used to access the Eclipse web properties such
	as the Wiki, Bugzilla as well as the code review system Gerrit.
	In order to contribute source code we need to review and sign
	the <a href="http://www.eclipse.org/legal/CLA.php">Eclipse.org
	Contributor License Agreement</a> and setup our account in
	Gerrit.
	</li>
	</ul></li>
	<li>Login to the <a
	href="https://dev.eclipse.org/site_login/?takemeback=https://projects.eclipse.org/user/login/sso">Eclipse
	projects forge</a> and complete the Contributor License
	Agreement
	</li>
	<li>Login to Gerrit and <a
	href="https://git.eclipse.org/r/login/settings/http-password">define
	a username</a></li>
	<li><a href="https://git.eclipse.org/r/login/settings/ssh-keys">Upload
	your public ssh-key</a> to Gerrit for authentication</li>
	</ol>

	<h2>Installing the Tools</h2>
	<p>
	All the tools we need are conveniently available as part of the <a
	href="http://www.eclipse.org/downloads/packages/eclipse-rcp-and-rap-developers/keplerr">Eclipse
	Kepler RCP and RAP Developers package</a>. We can also install the
	tools from their respective p2 repositories into any Eclipse
	instance using Install New Software from the Help menu:
	</p>
	<ul>
	<li><a href="http://eclipse.org/egit/">EGit</a> p2 repository -
	http://download.eclipse.org/egit/updates
	<ul>
	<li>Eclipse Git Team Provider</li>
	<li>Task Focused Interface for Eclipse Git Team Provider</li>
	</ul></li>
	<li><a href="http://eclipse.org/mylyn/">Mylyn</a> p2 repository -
	http://download.eclipse.org/mylyn/latest
	<ul>
	<li>Mylyn Tasks Connector: Bugzilla</li>
	<li>Mylyn Context Connector: Eclipse IDE</li>
	<li>Mylyn Builds Connector: Hudson/Jenkins</li>
	<li>Mylyn Reviews Connector: Gerrit</li>
	<li>Mylyn Version Connector: Git</li>
	</ul></li>
	</ul>

	<p>Some projects release frequently so installing directly from the
	project repositories has the benefit of getting the latest version.
	This tutorial is based on Mylyn 3.9.1 (Kepler SR1) which is
	available from the repository above.</p>

	<h2>Overview</h2>
	<p>Throughout the tutorial we’ll follow the typical steps for
	submitting a contribution to Eclipse.org. We’ll be using the Mylyn
	project as an example but the process is similar for most Eclipse
	projects:</p>
	<ol>
	<li>Querying the Eclipse.org Bugzilla for tasks</li>
	<li>Activating a Bugzilla task</li>
	<li>Committing and pushing a change to Git</li>
	<li>Monitoring the triggered build on Hudson</li>
	<li>Completing the resulting Gerrit code review</li>
	</ol>
	<p>We can complete the entire process from within the Eclipse IDE
	using the Eclipse tools provided by the Eclipse platform, EGit and
	Mylyn.</p>

	<h2>Querying Bugzilla</h2>
	<p>
	As a first step, we will look for a task in Bugzilla to work on. All
	Eclipse project use Bugzilla to track defects and requests for
	enhancements so it’s a good place to start. To make tasks from
	Bugzilla available in Eclipse we open the <i>Task List</i> view
	which is provided by Mylyn and right click to select <i>New > Query</i>
	from the context menu. The Eclipse.org Bugzilla repository is
	already pre-configured so we can select it and advance to the next
	page where we choose <i>Create query using form</i>. On the form
	page we enter a title and select <i>Mylyn Tasks</i> under <i>Product</i>
	and enter <i>helpwanted</i> under <i>Keywords</i>. <br /> <img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.1.png"
	alt="edit query" /><br />
	<br />


	<p>
	Queries are a personalized view of Bugzilla. They bring tasks we are
	interested in into the IDE and enable us to work with them. The
	query we created adds all tasks for the Mylyn Tasks project to the <i>Task
	List</i> that have been flagged by committers indicating that help
	from the community is desired. For this tutorial, we choose <a
	href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=325673">bug
	325673</a> which is about changing the default summary when
	creating new tasks with Mylyn but we could have picked any open
	task. We double click the task in the task list which opens a rich
	editor where we can review the description, comments, attachments
	and other details.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.2.png"
	alt="edit query" width="600" />
	<br />
	<br />

	<p>
	It’s good practice to state intention on a bug before starting to
	work on it to make others aware of our activity. In order to submit
	tasks we have to enter our account credentials by clicking the <i>Eclipse.org</i>
	link in the header of the Task Editor.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.3.png"
	alt="bugzilla repository settings" />
	<br />
	<br />

	<p>
	We can then refresh the task in the editor by clicking the <i>Synchronize
	Incoming Changes</i> button in the editor toolbar on the top
	right, enter a comment and submit our change.
	</p>

	<h2>Getting Source Code</h2>
	<p>Before we can start working on the task that we selected we need to
	get the source code. The Mylyn Tasks source code is hosted in a Git
	repository and managed by Gerrit.


	<p>
	To connect to the Eclipse.org Gerrit server we go back to the <i>Task
	List</i> and create another query for code reviews. We right click
	and select <i>New > Query</i> again. This time we have to use <i>Add
	Task Repository</i> and select <i>Gerrit Code Review</i> from the
	list. The server drop-down offers <i>Eclipse.org Reviews</i> as a
	template or we can enter <a
	href="https://git.eclipse.org/r/#/q/status:open,n,z">https://git.eclipse.org/r</a>
	as the server location. We also need to uncheck <i>Anonymous</i> and
	enter our Eclipse.org credentials.
	</p>
	<br />
	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.4.png"
	alt="gerrit repository settings" />
	<br />
	<br />

	<p>
	Back in the query dialog we enter a title and leave the default <i>My
	changes</i> selected. The query in the <i>Task List</i> will bring
	in our code reviews. If we haven’t submitted any code reviews, yet,
	it will remain empty initially.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.5.png"
	alt="query parameters" />
	<br />
	<br />

	<p>
	The next step is to import source code from Gerrit. Under <i>File >
	Import</i> we select <i>Projects from Git</i> and select <i>Gerrit</i>
	from the list on the next page. The selection page shows all Git
	repositories hosted on the Eclipse.org Gerrit instance. Since we
	want to contribute a change to Mylyn Tasks we select the <i>mylyn/org.eclipse.mylyn.tasks</i>
	repository.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.6.png"
	alt="source git repository" />
	<br />
	<br />

	<p>
	We can leave the defaults on the next pages and continue through the
	wizard. The repository is automatically cloned and we can select all
	projects to import on the last page. If an error is displayed that
	the SSH key is invalid or missing it needs to be generated first in
	the Eclipse preferences under <i>General > Network Connections >
	SSH2</i> and uploaded to Gerrit as described at the start of the
	tutorial.
	</p>

	<p>
	Once all projects have been imported we can get rid of the API
	baseline errors by opening the Eclipse preferences and selecting the
	<i>Plug-in Development > API Baselines</i> page and setting <i>Missing
	API baseline</i> to <i>Ignore</i>.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.7.png"
	alt="query parameters" />
	<br />
	<br />

	<h2>Working on Tasks</h2>
	<p>Back to our task at hand. We open the task in the task editor and
	use the blue ball button in the top left of the Task Editor to
	activate the task. Activating indicates that we are now working on
	the task.</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.8.png"
	alt="new task" />
	<br />
	<br />

	<p>
	The features of Mylyn’s task-focused interface are beyond the scope
	of this tutorial. In short, as we edit code and navigate the source
	code Mylyn monitors interactions and builds a degree-of-interest
	model for the active task. We can now focus views such as the <i>Package
	Explorer</i> using the <i>Focus on Active Task</i> button from a
	view’s toolbar. Based on our interactions, focusing filters all
	elements that are not relevant to the task at hand dramatically
	reducing information overload and distraction. We can always go back
	to seeing everything by de-selecting the focus button in the
	toolbar.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.9.png"
	alt="package explorer" />
	<br />
	<br />

	<p>
	Assuming that we have made the necessary code changes for the task
	we are working on and verified our changes locally we are ready to
	commit to the Git repository. Right clicking and selecting <i>Team >
	Commit</i> on a file brings up the commit dialog where we can
	provide a message describing the change. By default this is
	populated with the bug ID, summary and task URL of the active task.
	This automatically enables traceability between the task and change
	in the version control system.
	</p>

	<p>
	The commit dialog has an option to automatically generate a <i>Change-Id</i>
	which is used by Gerrit to track the change. If we want to update
	the commit later Gerrit can relate the changes based on the change
	ID. We can leave the default which is replaced by a generated,
	unique ID as soon we commit.
	</p>

	<p>
	Another important setting in the dialog is the <i>Add Signed-off</i>
	by toolbar button that adds another header to the commit message.
	The <i>Signed-off-by</i> header confirms that we are acting in
	agreement with the <a href="http://www.eclipse.org/legal/CLA.php">terms
	of the Eclipse.org CLA</a> and enables committers to later accept
	our contribution.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.10.png"
	alt="commit changes to git repository" />
	<br />
	<br />

	<p>
	Once we select <i>Commit</i> and <i>Push</i> the change is committed
	to our local clone of the Git repository and then pushed to the
	remote Git repository which in our case is a Gerrit server.
	</p>

	<p>
	When importing repositories from Gerrit the Eclipse Git integration
	creates a configuration that pushes to <i>refs/for/master</i>. This
	is a special location defined by Gerrit that causes every change to
	be staged in a new branch for verification and code reviewed before
	it is merged into the master branch.
	</p>

	<h2>Monitoring Builds</h2>
	<p>The Mylyn Tasks project has configured a job on a Hudson server
	that runs as code reviews are created or updated in Gerrit. Every
	time a new branch is detected a build is automatically triggered to
	verify the change. As soon as the builds completes Hudson comments
	and votes on the code review.</p>

	<p>
	To view Hudson build results in Eclipse we have to add the
	Eclipse.org Hudson server first. Typing <i>Builds</i> into <i>Quick
	Access</i> in the main toolbar opens the Builds view.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.11.png"
	alt="builds" />
	<br />
	<br />

	<p>
	We use the <i>New Builds Server</i> button in the toolbar and select
	Hudson from the list of server types. On the next page we enter the
	URL of the Hudson server <a
	href="https://hudson.eclipse.org/sandbox/">https://hudson.eclipse.org/hudson/</a>
	and <i>Refresh</i>.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.12.png"
	alt="build server properties" />
	<br />
	<br />

	<p>
	The selected build plans are now shown in the <i>Builds</i> view and
	we can monitor the results in the <i>Builds</i> view without
	switching to the browser.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.13.png"
	alt="builds" />
	<br />
	<br />

	<h2>Getting Feedback</h2>

	<p>
	We now go back to the <i>Task List</i> and use the <i>Synchronize
	Changed</i> button in the toolbar to make the code review we just
	created visible in Eclipse. A little popup notification is displayed
	and the review is decorated with a blue arrow indicating that it has
	changes that we haven’t yet looked at. Opening the code review
	displays a rich editor similar to the <i>Task Editor</i> for
	Bugzilla. We can review the changes, called patch sets, and the
	review comments.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.14.png"
	alt="review comments" />
	<br />
	<br />

	<p>When we refresh the code review editor we notice that the review
	has received one vote already. The +1 in the Verified category is
	from Hudson indicating that the all tests passed. Now we need one or
	more people to review and approve the actual code change. Anyone who
	has an Eclipse.org account can participate in code reviews and cast
	their votes but in order to pass the code review a +2 is required.
	On Eclipse.org only committers or the respective project have the
	right to vote +2.</p>

	<p>
	We can explicitly add people in the <i>Code Reviewers</i> section if
	we know their Eclipse.org account ID or we can wait for someone to
	pick up the change. Committers are expected to monitor code reviews
	for their project and should respond within a few days. If nobody
	reacts to the code review it sometimes help to post the URL of the
	code review on the corresponding Bugzilla task explicitly asking for
	a review.
	</p>

	<p>While this workflow is described from the perspective of a
	contributor it’s important to know that committers would follow the
	exact same workflow and post their changes to Gerrit so other
	committers or members from the community can provide feedback before
	a change is merged.</p>

	<h2>Reviewing Code</h2>

	<p>
	The first step to review the code in the IDE is to open the code
	review from the <i>Task List</i>. The content under review is listed
	in the <i>Patch Sets</i> section. Each patch set corresponds to one
	commit on the Gerrit server and is tracked in a separate Git branch.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.15.png"
	alt="patch sets" />
	<br />
	<br />

	<p>
	Double clicking a file from a patch set opens an editor that shows
	the base revision on the left and the proposed changes on the right.
	Comments are added by selecting any line, right clicking and
	selecting <i>Add Comment</i>. Initially, comments are saved as
	drafts and are not visible to others.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.16.png"
	alt="comment" />
	<br />
	<br />

	<p>
	After we have added comments we need to vote on the overall change
	and publish comments to make them visible to everyone. To do that we
	select <i>Publish</i> from the review editor which open a dialog.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.17.png"
	alt="publish comment" />
	<br />
	<br />

	<p>
	The <i>IP Clean</i> flag indicates that all requirements of the
	Eclipse IP process such as a valid CLA and copyright headers in
	changed files have been met. Only committers can set that flag. The
	same applies to the <i>Code Review</i> category. Only project
	committers have permission to vote +2 and submit the review as a
	last step.
	</p>

	<img
	src="/community/eclipse_newsletter/2013/september/images/septarticle4.18.png"
	alt="review merge" />
	<br />
	<br />

	<p>Once a review is submitted by a committer, the most recent patch
	set on the review is merged into the master branch by Gerrit. This
	completes the contribution cycle and the new feature is now part of
	Mylyn.</p>

	<h2>Further Reading</h2>
	<ul>
	<li><a href="http://wiki.eclipse.org/Mylyn/Contributor_Reference">Mylyn
	Contributor Reference</a></li>
	</ul>

	<div class="bottomitem">
	<h3>About the Authors</h3>

	<div class="row">
	<div class="col-sm-12">
	<div class="row">
	<div class="col-sm-8">
	<img class="author-picture"
	src="/community/eclipse_newsletter/2013/september/images/steffen75.jpg"
	alt="Steffen Pingel" />
	</div>
	<div class="col-sm-16">
	<p class="author-name">
	Steffen Pingel<br />
	<a target="_blank" href="http://www.tasktop.com/">Tasktop</a>
	</p>
	<ul class="author-link">
	<li><a target="_blank"
	href="http://tasktop.com/blog/author/steffenpingel">Blog</a></li>
	<li><a target="_blank" href="https://twitter.com/steffen_pingel">Twitter</a></li>
	</ul>
	</div>
	</div>
	</div>
	</div>
	</div>

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