Information for Developers

From PKP Wiki
Revision as of 12:45, 13 May 2013 by Jmacgreg (Talk | contribs)

Jump to: navigation, search

Managing Contributions

PKP code development, including external contributions, is managed between Bugzilla and Github. We prefer that issues be opened as either bugs or feature requests in Bugzilla, and that fixes are submitted as pull requests via Github, but we do still accept patches uploaded to Bugzilla itself if you do not want to submit via Github pull request.

Identifying an Issue

You can access our Bugzilla database here. We welcome any bug reports and feature requests, so long as they are understandably written and flagged correctly (mostly an issue of setting the severity between enhancement; trivial; minor; normal; major; critical; or blocker levels, although you can also set the priority as well if you'd like). You can see a great set of bug-writing guidelines here.

You are also advised to search for similar reports to avoid duplication.

Contributing Code

Contributing via Github

Contributing code via Github is our preferred method. Please see and for extensive instructions on the ins and outs of working with git repositories.

To contribute code back to us, feel free to submit a pull request from git.

If you are working against a particular entry in our Bugzilla database, use the following format for commit messages:

   *1234* My Commit Description

...where the 1234 is the bug ID from Bugzilla. This allows Bugzilla to track back to the commits made in that entry and helps us assemble release notes consistently.

Contributing Patches

If you cannot or do not want to contribute via Github, you can upload patches directly to bug reports. We're always happy to receive patches, whether for contribution to a project or for general community availability on the forums. The one thing we do ask is that you provide the patch in Unified Diff format. If you are using our git instructions to work with the application codebase (highly recommended), you can create unified diffs via git using the following command:

git diff -u ./ > patch.diff

... which will find all differences in the working directory and recursively, and write them to a file called patch.diff.

Applying Patches

Patching Manually

If you want to apply a patch manually, whether from Bugzilla or from Github, download it to your development environment, and from the application's root directory and run

patch -p0 < ./path/to/patch.diff

The --dry-run option to the patch tool allows you to safely test the patch to see if it will apply cleanly, and if not, where the conflicts will arise.

For more Windows (and general) information, also see this forum thread.

Patching from Github

You can grab "patches" from Github by finding that particular commit's has and cherry-picking it:

First, find the hash for the commit you want to apply locally. The hash is the last string in the commit's URL, for example for the commit found at it would be "4aba081d35133c1ee9a9e1f3b9166ca5db5fd48d".

Next, make sure your local repository is up to date (NB that this does not automatically merge all new remote commits to your repository, it just stores them locally):

git fetch 

Then, cherry-pick the commit you want to apply by hash:

git cherry-pick 4aba081d35133c1ee9a9e1f3b9166ca5db5fd48d

Setting up a flexible development environment

NB: This is not a beginner's installation/configuration tutorial. We only highlight a few important differences from a standard installation as a help for experienced PKP, database, PHP and web server users.

Install and Configure Databases

  • There is nothing special to the database installation. Use your OS' standard installation procedure to install the necessary databases you want to test in parallel.
  • Edit to switch the database connection.

Install and Configure supported PHP versions

  • Download or build the PHP binaries you want to test (newer versions can be downloaded from or are part of the standard OS distributions, older versions must be built from source).
  • You'll need the thread-safe version if you want to test mod_php in Apache.
  • Install all binaries and configuration separately. Do not create any shared files or configuration (separate php.ini, separate installation directories).
  • On Windows:
    • Get the PHP zip arquive distributions where available and unzip them into separate folders.
    • XAMPP has lots of old Windows binaries if the version you look for is no longer officially supported on
    • Download the thread-safe VC6 version as VC9 versions are not compatible with Apache.
    • Do not install DLL files in C:\WINDOWS or any other directory on the path.
    • Do not install any registry keys.
    • Do not configure any shared environment variables.
  • Exception: Install PEAR in a central folder that is accessible by all PHP versions. Install necessary PEAR dependencies (e.g. PHPUnit, etc.) - see separate documentation on this Wiki for that.
  • Edit the development php.ini files as required:
    • extension_dir must point to the absolute path of the version specific extension binaries
    • enable extensions required by PKP software (e.g. database client, GD, etc.)
    • optional: error_reporting, display_errors, log_errors, error_log, max_execution_time, xdebug
  • Test all PHP installations separately: /path/to/php -c /path/to/php.ini -v (This should discover most problems with wrong extension paths).

Install and Configure Apache

We use Apache so that we can test CGI, FCGI and Module configurations in parallel. Install Apache 2.2 (standard distribution for your OS). Then get and install mod_fcgid as explained on the linked web pages.

All the magic lies in Apache's httpd.conf. Here's the Windows version. It should be easy to adapt that to your specific OS:

#General CGI Support
<IfDefine CGI>
    LoadModule cgi_module modules/
    AddHandler application/x-httpd-php .php
#General FCGI Support
<IfDefine FCGI>
    LoadModule fcgid_module modules/
    AddHandler fcgid-script .php
    <Directory "C:/path/to/your/pkp/doc/root">
        Options +ExecCGI
#PHP 4.3 support
<IfDefine PHP43>
    <IfDefine CGI>
        Action application/x-httpd-php "/php-cgi/php.exe"
        ScriptAlias /php-cgi/ "C:/path/to/php43/"
        <Directory "C:/path/to/php43">
            Order allow,deny
            Allow from
#PHP 5.2 support
<IfDefine PHP52>
    <IfDefine MODULE>
        LoadFile "C:/path/to/php52/php5ts.dll"
        LoadFile "C:/path/to/php52/libmysql.dll" # This is required (PHP52 only) otherwise PHP might load libmysql.dll from MySQL's own bin
        LoadModule php5_module "C:/path/to/php52/php5apache2_2.dll"
        PHPIniDir "C:/path/to/php52"
    <IfDefine FCGI>
        FcgidWrapper "C:/path/to/php52/php-cgi.exe" .php
    <IfDefine CGI>
        Action application/x-httpd-php "/php-cgi/php-cgi.exe"
        ScriptAlias /php-cgi/ "C:/path/to/php52/"
        <Directory "C:/path/to/php52">
            Order allow,deny
            Allow from
#PHP 5.3 support
<IfDefine PHP53>
    <IfDefine MODULE>
        LoadFile "C:/path/to/php53/php5ts.dll"
        LoadModule php5_module "C:/path/to/php53/php5apache2_2.dll"
        PHPIniDir "C:/path/to/php53"
    <IfDefine FCGI>
        FcgidWrapper "C:/path/to/php53/php-cgi.exe" .php
    <IfDefine CGI>
        Action application/x-httpd-php "/php-cgi/php-cgi.exe"
        ScriptAlias /php-cgi/ "C:/path/to/php53/"
        <Directory "C:/path/to/php53">
            Order allow,deny
            Allow from
DocumentRoot "C:/path/to/your/pkp/doc/root"
<Directory "C:/path/to/your/pkp/doc/root">
    Options +FollowSymLinks
    AllowOverride All
    Order allow,deny
    Allow from all

Now all you need to switch configurations is starting Apache like this:


A few examples:

http -DPHP43 -DCGI
http -DPHP53 -DFCGI