Collaborating

Overview

Teaching: 25 min
Exercises: 0 min

Questions

• How can I use version control to collaborate with other people?

Objectives

• Clone a remote repository.

• Collaborate pushing to a common repository.

For the next step, get into pairs. One person will be the “Owner” and the other will be the “Collaborator”. The goal is that the Collaborator add changes into the Owner’s repository. We will switch roles at the end, so both persons will play Owner and Collaborator.

The Owner needs to give the Collaborator access. On GitHub, click the settings button on the right, then select Collaborators, and enter your partner’s username.

To accept access to the Owner’s repo, the Collaborator needs to go to https://github.com/notifications. Once there she can accept access to the Owner’s repo.

Next, the Collaborator needs to download a copy of the Owner’s repository to her machine. This is called “cloning a repo”. To clone the Owner’s repo into her Desktop folder, the Collaborator clicks Clone Respository from the File menu:

Then the Collaborator enters the URL or the Owner’s username/respository in the first line of the pop-up window. The Collaborator then makes sure the correct destination directory is set on her local machine. Then she clicks Clone.

The Collaborator can now make a change in her clone of the Owner’s repository, exactly the same way as we’ve been doing before via Excel or a text editor.

After committing the changes click the Push Origin tab at the top.

Take a look to the Owner’s repository on its GitHub website now (maybe you need to refresh your browser.) You should be able to see the new commit made by the Collaborator.

To download the Collaborator’s changes from GitHub, the Owner now clicks the Pull Origin button (or Fetch Origin and then Pull Origin).

Clicking the History tab will show the new changes locally.

Now the three repositories (Owner’s local, Collaborator’s local, and Owner’s on GitHub) are back in sync.

A Basic Collaborative Workflow

In practice, it is good to be sure that you have an updated version of the repository you are collaborating on, so you should git pull before making our changes. The basic collaborative workflow would be:

• update your local repo with git pull origin master,
• make your changes and stage them with git add,
• commit your changes with git commit -m, and
• upload the changes to GitHub with git push origin master

It is better to make many commits with smaller changes rather than of one commit with massive changes: small commits are easier to read and review.

Switch Roles and Repeat

Switch roles and repeat the whole process.

Review Changes

The Owner push commits to the repository without giving any information to the Collaborator. How can the Collaborator find out what has changed with command line? And on GitHub?

Solution

On the command line, the Collaborator can use git fetch origin master to get the remote changes into the local repository, but without merging them. Then by running git diff master origin/master the Collaborator will see the changes output in the terminal.

On GitHub, the Collaborator can go to their own fork of the repository and look right above the light blue latest commit bar for a gray bar saying “This branch is 1 commit behind Our-Repository:master.” On the far right of that gray bar is a Compare icon and link. On the Compare page the Collaborator should change the base fork to their own repository, then click the link in the paragraph above to “compare across forks”, and finally change the head fork to the main repository. This will show all the commits that are different.

Comment Changes in GitHub

The Collaborator has some questions about one line change made by the Owner and has some suggestions to propose.

With GitHub, it is possible to comment the diff of a commit. Over the line of code to comment, a blue comment icon appears to open a comment window.

The Collaborator posts its comments and suggestions using GitHub interface.

Version History, Backup, and Version Control

Some backup software can keep a history of the versions of your files. They also allows you to recover specific versions. How is this functionality different from version control? What are some of the benefits of using version control, Git and GitHub?

Key Points

• git clone copies a remote repository to create a local repository with a remote called origin automatically set up.