Egit : Prevent a commit if not formatted correctly - eclipse

The company I work for gave me the project of moving their java project from CVS to Git.
For several reasons, they don't want to use another tool than Eclipse. So we're stuck with EGit.
I know it is possible to configure Eclipse to format code. But it seems like there is nothing that would prevent someone to use his own way of formatting the code.
So my question is, is it possible to refuse a commit with EGit if the code is not formatted correctly ? The reason behind this question is that we want to avoid conflicts due to the code format, which was a really big problem in CVS.
Thank you

I recommend setting the formatter and a save action to format code as a project-specific configuration. Then tracking the .settings directory in Git.
Because it's configured in the project and in version control, developers won't have to configure Eclipse themselves, it's automatic.
We have done this with several projects and if you do it from the start, you will never have any ill-formatted code or discussions about it.
If a developer is really reluctant and even goes as far as unchecking the project-specific formatter and using another one, maybe you should have a talk.
(By the way, a recommended option in the formatter is Never join already wrapped lines, because sometimes the formatter will do weird wrapping. This option makes it possible to have control over wrapping.)

An alternative to checking the code during the commit is a scenario where gerrit is used as review system. The developers would commit their code to gerrit instead of directly to the git repository. Gerrit can then trigger a build job on a Jenkins/Hudson server and that build job can run CheckStyle or any other format checking tool you prefer.
On successful check Jenkins could then also verify the change and merge it into the git repository (most projects prefer Jenkins to only verify the correctness of the code, and a human still needs to review the code afterwards). Commits failing the check would remain in gerrit (and a mail would go to the developer).
The advantage of this approach is that you can do much more than only style checks for each commit, especially run unit tests, static code analysis and code coverage. The major drawback is that you have to set up some more tools than just a git hook.

If you know a way to determine if the code is formatted correctly you can implement this in the hook pre-commit
This hook should be placed in .git/hooks
git comes with a sample, called pre-commit.sample, it either in the hooks directory already or you can find it in the /usr/share/git-core/templates/hooks/ (On Ubuntu).

Related

Struggling with managing my eclipse workspace and what to do about syncing it between two machines

I'm trying to sync my workspace with PC<---->Laptop. PC is windows, the laptop is ubuntu Linux. Both have 5.1 Mars eclipse version.
So far I've been using dropbox to sync in between but problems started occurring but managed to solve them. I was compiling classes with a newer version of java and the other eclipse didn't know what to do. Syncing with dropbox is really not an elegant way of doing this.
So now I'm trying out git, but so far I've been confused by it and how it works. I have managed to set the git plugin in the eclipse but not sure what to do next. The plugin is called EGit.
As far as I understand so far, it works like this? workspace--->local repo---->git repo? Then I would have to manually sync the code back on my laptop by entering the commands in terminal?
I already did push some stuff to my private repository, but that was on my laptop.
Is it possible to setup an easy way to sync the code? I know git is a good versioning system and a good way to keep the code updated? I'm a first year CS student and so far I don't have any complicated or large projects to manage with. I'm just looking for a nice way to sync the code. I guess having git setup is an ok way to go about it, but I'm overwhelmed by the features of git and not really grasping it.
Thanks for reading.
It would be a good idea to learn how to do it right. It's a better investment of your time than working on workarounds which only work in a certain situation or which are of limited use. Yes, you could use git for that. You do not really need the EGit plugin, just use the git command line, in my opinion that is easier. There are a bunch of great git tutorials out there. For the beginning the basic commands like git init, clone, pull, status, diff, add, commit, push are sufficient. You would need a central git repository, get a free GitHub account for that purpose.
Compiled classes should not be commited into your source repository. Add folders with any generated files to your .gitignore file.

Git: Automatically Commit on Publish or Restart of Web Aplication

When developing on my local, I would like to automatically commit all outstanding changes to Git every time I republishing my web project in Eclipse. This way I can get a good view of the steps that I took in my development activities. I will of course rebase before pushing to the public repository. I only want to use this for local history.
Some details:
Eclipse
Weblogic 10.3.5
Web Project
I am looking for a solution that will not require me to change the project itself, so any solution that requires changes to my Servlet class, or to the web.xml will not be satisfactory, although I guess I can do that as a last resort.
Additional Information
I have found that there is a Builders section under a project's properties. This can be configure to do whatever I want, but the only options seem to be to ether run it when manually building, during or after a clean (all of which will not commit often enough), or after an automatic build (which happens every time I save a file, making it way too often too be useful).
automatically commit all outstanding changes to Git every time I republish my project.
"Automatically" and "outstanding changes" cannot coexist in the same sentence without some details about the criteria which would define an "outstanding change": an "automatic" process wouldn't know when a change is supposed to be outstanding or not.
That means an "on demand" process might be easier to implement, and call when needed.
Plus the commit message might be important to refine, as it is a big part of having a "good view of the steps that I took in my development activities."
Whatever the Eclipse project is (here a WebLogic one), that process might simply be doing a add/commit through:
EGit commands (manually called through the EGit GUI, in order to fill-in a meaningful commit message)
or a script, and which would allows (if needed) for a post-commit hook to push that commit to a remote hosting service (like GitHub for instance), since the same commit with EGit would not trigger the post-commit hook.
Since this is supposed to be fully automatic, the other approach would be to use an ant script to trigger the "redeploy" of the weblogic app.
See for instance "Weblogic hot deployment during development (like WSSD/RAD)".
That ant script (using a wdeploy ant task) could then make sure the redeploy target depends on another ant target which would commit and push first (like in this gist).

Half-ignored files in VCS - is this supported?

I am using Eclipse and Subversion for Java development, and I find myself wishing for a feature in version control systems (one that is not available in SVN, to the best of my knowledge).
I would like my project settings files to be half-ignored. To be more precise, I want them to be available in VCS, I want merge to occur when someone checks in changes, but. I want my own changes ignored unless I very explicitly tell the system to take them.
This would allow me to have my local paths (and other settings) in my local configuration w/o screwing up other people's configuration. But, when I have a substantial change, I can still check it in (very very carefully, may be temporarily removing my other local changes) and have it delivered to other people.
Now, the actual question: is there any VCS that supports this feature? Or may be I am missing something in SVN? How do other people solve this problem in Eclipse?
Yes, Git support that feature through filter driver (a clean script can run upon commit, allowing you to clean the content from any of your changes if you want).
But another way would be to never version that setting file, and only version:
a template file
a value file
a script able to replace variables in the template files with the values from the value file, in order to generate the actual (and "private", as in "not versioned") setting file.
That way, you can modifying it at your heart's content without ever committing your changes.
.gitignore for git, .hgignore for mercurial and file paths and patterns can be added that will not be committed. There similar in SVN but i never worked out how to use it myself but my sysop did set it up form me.
git supports this with
git update-index --assume-unchanged <file>
and the complementary
git update-index --no-assume-unchanged <file>
See http://blog.pagebakers.nl/2009/01/29/git-ignoring-changes-in-tracked-files and http://kernel.org/pub/software/scm/git/docs/git-update-index.html#_options for more details.

Managing web project over multiple hosts with revision control

Greetings! :-)
I would like to describe a workflow strategy with some gaps in it, and I would be glad if you could fill in the gaps and otherwise give comments. If admins think that this does not validate as a question, then please delete away.
I am working on a webproject having files with PHP, Javascript (jQuery), HTML, CSS and postgresql code for in-database functions, table creation and configuration. All files are changed frequently. I use Apache.
This is what I want:
Introduce revision control.
Use build files for managing compilation and revision control.
Start using a proper IDE.
Be able to hack on my stationary and laptop with little time wasted on keeping code and IDE project configurations synchronized.
Have a setup for the project so some friends (approx 4-5) may join the project in the future.
This is what I am planning to start to use:
Bazaar for revision control and "project distribution".
Ant for build files.
Eclipse setup with proper plugins for managing Bazaar and Ant.
With Bazaar I intend to put code files, build files and even Eclipse project configuration files (configuration files of the project that I create in Eclipse to work with the webproject) under revision control. That way I can pull all that stuff from my stationary to my laptop via Bazaar.
Since I also put Eclipse's project conf files under revision control, I expect that I can without hazzle immediately open the Eclipse project directly on my laptop. So even if I make modifications to the project settings in Eclipse this should also be synchronized over laptop and host.
But I do have a few questions. Do you know how I should use bazaar so that I am notified or stopped when I try to modify the code on my stationary but have forgotten to push/check-in modifications from my laptop?
Also how should I setup Bazaar so that others can easily join the project in the future? I dont like using a service like launchpad, and would like my stationary to be the server. Is it not a bit risky to do it through ssh because I would have to create a new user account on my stationary each time a new user wants to join in?
Thoughts? Comments? It would be appreciated.
On the first question, you should consider using "checkouts", also called bound branches. That makes bzr behave more like svn in that every commit automatically goes to the "server" and you can't forget to push. Of course, bzr can't really detect if you forget to commit something.
On the second question, you can set up a bzr server that runs over HTTP/DAV and uses the web server's authentication methods. However, if you don't really like other people using your machine as a server, you might want to consider using a totally distributed approach, where your codevelopers publish their own branches and you pull in the things you want.
The Bazaar documentation is quite good and has the details on these topics.

How to actually use a source control system?

So I get that most of you are frowning at me for not currently using any source control. I want to, I really do, now that I've spent some time reading the questions / answers here. I am a hobby programmer and really don't do much more than tinker, but I've been bitten a couple of times now not having the 'time machine' handy...
I still have to decide which product I'll go with, but that's not relevant to this question.
I'm really struggling with the flow of files under source control, so much so I'm not even sure how to pose the question sensibly.
Currently I have a directory hierarchy where all my PHP files live in a Linux Environment. I edit them there and can hit refresh on my browser to see what happens.
As I understand it, my files now live in a different place. When I want to edit, I check it out and edit away. But what is my substitute for F5? How do I test it? Do I have to check it back in, then hit F5? I admit to a good bit of trial and error in my work. I suspect I'm going to get tired of checking in and out real quick for the frequent small changes I tend to make. I have to be missing something, right?
Can anyone step me through where everything lives and how I test along the way, while keeping true to the goal of having a 'time machine' handy?
Eric Sink has a great series of posts on source control basics. His company (Sourcegear) makes a source control tool called Vault, but the how-to is generally pretty system agnostic.
Don't edit your code on production.
Create a development environment, with the appropriate services (apache w/mod_php).
The application directory within your dev environment is where you do your work.
Put your current production app in there.
Commit this directory to the source control tool. (now you have populated source control with your application)
Make changes in your new development environment, hitting F5 when you want to see/test what you've changed.
Merge/Commit your changes to source control.
Actually, your files, while stored in a source repository (big word for another place on your hard drive, or a hard drive somewhere else), can also exist on your local machine, too, just where they exist now.
So, all files that aren't checked out would be marked as "read only", if you are using VSS (not sure about SVN, CVS, etc). So, you could still run your website by hitting "F5" and it will reload the files where they currently are. If you check one out and are editing it, it becomes NOT read only, and you can change it.
Regardless, the web server that you are running will load readonly/writable files with the same effect.
You still have all the files on your hard drive, ready for F5!
The difference is that you can "checkpoint" your files into the repository. Your daily life doesn't have to change at all.
You can do a "checkout" to the same directory where you currently work so that doesn't have to change. Basically your working directory doesn't need to change.
This is a wildly open ended question because how you use a SCM depends heavily on which SCM you choose. A distributed SCM like git works very differently from a centralized one like Subversion.
svn is way easier to digest for the "new user", but git can be a little more powerful and improve your workflow. Subversion also has really great docs and tool support (like trac), and an online book that you should read:
http://svnbook.red-bean.com/
It will cover the basics of source control management which will help you in some way no matter which SCM you ultimately choose, so I recommend skimming the first few chapters.
edit: Let me point out why people are frowning on you, by the way: SCM is more than simply a "backup of your code". Having "timemachine" is nothing like an SCM. With an SCM you can go back in your change history and see what you actually changed and when which is something you'll never get with blobs of code. I'm sure you've asked yourself on more than one occasion: "how did this code get here?" or "I thought I fixed that bug"-- if you did, thats why you need SCM.
You don't "have" to change your workflow in a drastic way. You could, and in some cases you should, but that's not something version control dictates.
You just use the files as you would normally. Only under version control, once you reach a certain state of "finished" or at least "working" (solved an issue in your issue tracker, finished a certain method, tweaked something, etc), you check it in.
If you have more than one developer working on your codebase, be sure to update regularly, so you're always working against a recent (merged) version of the code.
Here is the general workflow that you'd use with a non-centralized source control system like CVS or Subversion: At first you import your current project into the so-called repository, a versioned storage of all your files. Take care only to import hand-generated files (source, data files, makefiles, project files). Generated files (object files, executables, generated documentation) should not be put into the repository.
Then you have to check out your working copy. As the name implies, this is where you will do all your local edits, where you will compile and where you will point your test server at. It's basically the replacement to where you worked at before. You only need to do these steps once per project (although you could check out multiple working copies, of course.)
This is the basic work cycle: At first you check out all changes made in the repository into your local working copy. When working in a team, this would bring in any changes other team members made since your last check out. Then you do your work. When you've finished with a set of work, you should check out the current version again and resolve possible conflicts due to changes by other team members. (In a disciplined team, this is usually not a problem.) Test, and when everything works as expected you commit (check in) your changes. Then you can continue working, and once you've finished again, check out, resolve conflicts, and check in again. Please note that you should only commit changes that were tested and work. How often you check in is a matter of taste, but a general rule says that you should commit your changes at least once at the end of your day. Personally, I commit my changes much more often than that, basically whenever I made a set of related changes that pass all tests.
Great question. With source control you can still do your "F5" refresh process. But after each edit (or a few minor edits) you want to check your code in so you have a copy backed up.
Depending on the source control system, you don't have to explicitly check out the file each time. Just editing the file will check it out. I've written a visual guide to source control that many people have found useful when grokking the basics.
I would recommend a distributed version control system (mercurial, git, bazaar, darcs) rather than a centralized version control system (cvs, svn). They're much easier to setup and work with.
Try mercurial (which is the VCS that I used to understand how version control works) and then if you like you can even move to git.
There's a really nice introductory tutorial on Mercurial's homepage: Understanding Mercurial. That will introduce you to the basic concepts on VCS and how things work. It's really great. After that I suggest you move on to the Mercurial tutorials: Mercurial tutorial page, which will teach you how to actually use Mercurial. Finally, you have a free ebook that is a really great reference on how to use Mercurial: Distributed Revision Control with Mercurial
If you're feeling more adventurous and want to start off with Git straight away, then this free ebook is a great place to start: Git Magic (Very easy read)
In the end, no matter what VCS tool you choose, what you'll end up doing is the following:
Have a repository that you don't manually edit, it only for the VCS
Have a working directory, where you make your changes as usual.
Change what you like, press F5 as many times as you wish. When you like what you've done and think you would like to save the project the way it is at that very moment (much like you would do when you're, for example, writing something in Word) you can then commit your changes to the repository.
If you ever need to go back to a certain state in your project you now have the power to do so.
And that's pretty much it.
If you are using Subversion, you check out your files once . Then, whenever you have made big changes (or are going to lunch or whatever), you commit them to the server. That way you can keep your old work flow by pressing F5, but every time you commit you save a copy of all the files in their current state in your SVN-repository.
Depends on the source control system you use. For example, for subversion and cvs your files can reside in a remote location, but you always check out your own copy of them locally. This local copy (often referred to as the working copy) are just regular files on the filesystem with some meta-data to let you upload your changes back to the server.
If you are using Subversion here's a good tutorial.
Depending on the source control system, 'checkout' may mean different things. In the SVN world, it just means retrieving (could be an update, could be a new file) the latest copy from the repository. In the source-safe world, that generally means updating the existing file and locking it. The text below uses the SVN meaning:
Using PHP, what you want to do is checkout your entire project/site to a working folder on a test apache site. You should have the repository set up so this can happen with a single checkout, including any necessary sub folders. You checkout your project to set this up one time.
Now you can make your changes and hit F5 to refresh as normal. When you're happy with a set of changes to support a particular fix or feature, you can commit in as a unit (with appropriate comments, of course). This puts the latest version in the repository.
Checking out/committing one file at a time would be a hassle.
A source control system is generally a storage place for your files and their history and usually separate from the files you're currently working on. It depends a bit on the type of version control system but suppose you're using something CVS-like (like subversion), then all your files will live in two (or more) places. You have the files in your local directory, the so called "working copy" and one in the repository, which can be located in another local folder, or on another machine, usually accessed over the network. Usually, after the first import of your files into the repository you check them out under a working folder where you continue working on them. I assume that would be the folder where your PHP files now live.
Now what happens when you've checked out a copy and you made some non-trivial changes that you want to "save"? You simply commit those changes in your working copy to the version control system. Now you have a history of your changes. Should you at any point wish to go back to the version at which you committed those changes, then you can simply revert your working copy to an older revision (the name given to the set of changes that you commit at once).
Note that this is all very CVS/SVN-specific, as GIT would work slightly different. I'd recommend starting with subversion and reading the first few chapters of the very excellent SVN Book to get you started.
This is all very subjective depending on the the source control solution that you decide to use. One that you will definitely want to look into is Subversion.
You mentioned that you're doing PHP, but are you doing it in a Linux environment or Windows? It's not really important, but what I typically did when I worked in a PHP environment was to have a production branch and a development branch. This allowed me to configure a cron job (a scheduled task in Windows) for automatically pulling from the production-ready branch for the production server, while pulling from the development branch for my dev server.
Once you decide on a tool, you should really spend some time learning how it works. The concepts of checking in and checking out don't apply to all source control solutions, for example. Either way, I'd highly recommend that you pick one that permits branching. This article goes over a great (in my opinion) source control model to follow in a production environment.
Of course, I state all this having not "tinkered" in years. I've been doing professional development for some time and my techniques might be overkill for somebody in your position. Not to say that there's anything wrong with that, however.
I just want to add that the system that I think was easiest to set up and work with was Mercurial. If you work alone and not in a team you just initialize it in your normal work folder and then go on from there. The normal flow is to edit any file using your favourite editor and then to a checkin (commit).
I havn't tried GIT but I assume it is very similar. Monotone was a little bit harder to get started with. These are all distributed source control systems.
It sounds like you're asking about how to use source control to manage releases.
Here's some general guidance that's not specific to websites:
Use a local copy for developing changes
Compile (if applicable) and test your changes before checking in
Run automated builds and tests as often as possible (at least daily)
Version your daily builds (have some way of specifying the exact bits of code corresponding to a particular build and test run)
If possible, use separate branches for major releases (or have a development and a release branch)
When necessary, stabilize your code base (define a set of tests such that passing all of those tests means you are confident enough in the quality of your product to release it, then drive toward 0 test failures, i.e. ban any checkins to the release branch other than fixes for the outstanding issues)
When you have a build which has the features you want and has passed all of the necessary tests, deploy it.
If you have a small team, a stable product, a fast build, and efficient, high-quality tests then this entire process might be 100% automated and could take place in minutes.
I recommend Subversion. Setting up a repository and using it is actually fairly trivial, even from the command line. Here's how it would go:
if you haven't setup your repo (repository)
1) Make sure you've got Subversion installed on your server
$ which svn
/usr/bin/svn
which is a tool that tells you the path to another tool. if it returns nothing that tool is not installed on your system
1b) If not, get it
$ apt-get install subversion
apt-get is a tool that installs other tools onto your system
If that's not the right name for subversion in apt, try this
$ apt-cache search subversion
or this
$ apt-cache search svn
Find the right package name and install it using apt-get install packagename
2) Create a new repository on your server
$ cd /path/to/directory/of/repositories
$ svnadmin create my_repository
svnadmin create reponame creates a new repository in the present working directory (pwd) with the name reponame
You are officially done creating your repository
if you have an existing repo, or have finished setting it up
1) Make sure you've got Subversion installed on your local machine per the instructions above
2) Check out the repository to your local machine
$ cd /repos/on/your/local/machine
$ svn co svn+ssh://www.myserver.com/path/to/directory/of/repositories/my_repository
svn co is the command you use to check out a repository
3) Create your initial directory structure (optional)
$ cd /repos/on/your/local/machine
$ cd my_repository
$ svn mkdir branches
$ svn mkdir tags
$ svn mkdir trunk
$ svn commit -m "Initial structure"
svn mkdir runs a regular mkdir and creates a directory in the present working directory with the name you supply after typing svn mkdir and then adds it to the repository.
svn commit -m "" sends your changes to the repository and updates it. Whatever you place in the quotes after -m is the comment for this commit (make it count!).
The "working copy" of your code would go in the trunk directory. branches is used for working on individual projects outside of trunk; each directory in branches is a copy of trunk for a different sub project. tags is used more releases. I suggest just focusing on trunk for a while and getting used to Subversion.
working with your repo
1) Add code to your repository
$ cd /repos/on/your/local/machine
$ svn add my_new_file.ext
$ svn add some/new/directory
$ svn add some/directory/*
$ svn add some/directory/*.ext
The second to last line adds every file in that directory. The last line adds every file with the extension .ext.
2) Check the status of your repository
$ cd /repos/on/your/local/machine
$ svn status
That will tell you if there are any new files, and updated files, and files with conflicts (differences between your local version and the version on the server), etc.
3) Update your local copy of your repository
$ cd /repos/on/your/local/machine
$ svn up
Updating pulls any new changes from the server you don't already have
svn up does care what directory you're in. If you want to update your entire repository, makre sure you're in the root directory of the repository (above trunk)
That's all you really need to know to get started. For more information I recommend you check out the Subversion Book.