Development tools

XF2 provides developers with a number of built in tools you can use to expedite development of add-ons and we'll go through some of these below.

Debug mode

Debug mode can be enabled in your config.php which will allow you to access certain development tools in the Admin CP (such as creating routes, permissions, admin navigation etd.) and it will also enable an output at the bottom of every page which details how long the page took to process, how many queries were executed to render the page and how much memory was used. A tooltip containing information about the current controller, action and template name is available on hover. You can also click on the time output and this will give you a detailed look at exactly what queries ran and the stack trace that led to that query being executed.

You can enable debug mode by adding the following to config.php:

$config['debug'] = true;

Enabling development mode

Development mode is a special mode, activated in your config.php file which will trigger XF to automatically write out your development files to your _output directory. This mode needs to be enabled for filesystem template editing to be enabled. As development mode will be writing files to your file system it is important to ensure you have the appropriate file permissions in place. This may vary depending on environment, but a typical configuration would be to ensure that for any add-on you are working on, you have its _output directory set chmod to 0777. For example, if you are working on an add-on with an ID of Demo, its development output will be written out to src/addons/Demo/_output and therefore that directory will need to be fully writable.

Enabling development mode, also enables debug mode automatically.

To enable development mode, add the following lines to your config.php file:

$config['development']['enabled'] = true;
$config['development']['defaultAddOn'] = 'SomeCompany/MyAddOn';

The defaultAddOn value is optional, but adding that will automatically populate the specified add-on in the XF Admin CP when creating new content which will be associated to an add-on.

In addition to the above, you may find it necessary to add some additional configuration, especially if you are using more than one XF installation.

$config['enableMail'] = false;

This will disable all mail from being sent from your board. This is especially important if you are using a copy of live data with real users and real email addresses (though we would advise against this!).

As an alternative to disabling mail directly, you may want to consider using a service such as This provides you with a free mailbox that will receive all emails sent from your board, which is very useful for testing any emails your new add-on may be sending.

$config['cookie']['prefix'] = 'anything_';

If you're using two or more XF installs on the same domain, you may experience issues with cookies being overwritten, which is caused by the installations sharing the same cookie prefix. It's therefore recommended to ensure you change the cookie prefix for each XF install you have set up. Without doing that, you will experience issues, for example, getting logged out of one XF install when logging into another.

Development commands

XF 2.0 ships with a number of general development and add-on CLI commands which are aimed to help you develop more efficiently or even possibly automate/script some common processes.

In this section we'll go through some of the common tools and explain what they do.

Add-on specific commands

Creating a new add-on


$ php cmd.php xf-addon:create

The xf-addon:create command is how to initially set up and create a new add-on. Once it runs, all you need to answer are some basic questions:

  • Enter an ID for this add-on
  • Enter a title
  • Enter a version ID (e.g. 1000010)
  • Enter a version string (e.g. 1.0.0 Alpha)

You will then be given the option to create the add-on and write out its addon.json file, and asked some questions about whether you want to add a Setup.php file.

Export _data .XML files


$ php cmd.php xf-addon:export [addon_id]

This command is what you will use to export all of your add-on's data to XML files inside the _data directory. It exports the data from what is currently in the database (rather than from the development output files).

Bump your add-on version


$ php cmd.php xf-addon:bump-version [addon_id] --version-id 1020370 --version-string 1.2.3

This command takes the add-on ID for your add-on, the new version ID and the new version string. This enables you to bump the version of your add-on in a single step, without having to perform upgrades and rebuilds yourself. The options above are optional, and if they are not provided you will be prompted for them. If you only specify the version ID, we will try and infer the correct version string from that automatically if it matches our Recommended version ID format. Once the command completes, it updates the addon.json file automatically and the database with the correct version details.

Sync your addon.json to the database


$ php cmd.php xf-addon:sync-json [addon_id]

Sometimes you might prefer to edit the JSON file directly with certain details. This could be the version, or a new icon, or a change of title or description. Changing the JSON in this way can cause the add-on system to believe there are pending changes or that the add-on is upgradeable. A rebuild or upgrade can be a destructive operation if you haven't yet exported your current data. Therefore, running this command is recommended as a way of importing that data in without affecting your existing data.

Validate your addon.json file


$ php cmd.php xf-addon:validate-json [addon_id]

If you'd like to check your JSON file contains the correct content and in the correct format, you can now validate it. The validator will check that the content can be decoded, that it contains all of the correct required fields (such as title and version ID) and also checks for the presence of the optional keys (such as description and icon). If any keys are missing, you will be offered to have the issues fixed for you. We also check to see if there are any unexpected fields within the JSON file. These may be deliberate or represent typos. You can run the command manually or the command will be run automatically while building your release.

Run a specific Setup step

Sometimes it's useful to check that your Setup class steps function correctly, without having to go through the process of uninstalling and reinstalling.

There are three commands which help with this. These commands will only work with Setup classes that are built using the default StepRunner traits.

Run an install step


$ php cmd.php xf-addon:install-step [addon_id] [step]

Run an upgrade step


$ php cmd.php xf-addon:upgrade-step [addon_id] [version] [step]

Run an uninstall step


$ php cmd.php xf-addon:uninstall-step [addon_id] [step]

Building an add-on release

Once all of the hard work has been done, it's a shame to have to go through a number of other processes before you can actually release it. Even the process of collecting all of the files into the correct place and creating the ZIP file manually can be time consuming and prone to errors. We can take care of that automatically, including generating the hashes.json file, with one simple command.


$ php cmd.php xf-addon:build-release [addon_id]

When you run this command, it will first run the xf-addon:export command before then collecting all of your files together into a temporary _build directory and writing them to a ZIP file. The finished ZIP will also include the hashes.json file. Once the ZIP has been created it will be saved to your _releases directory named and named <ADDON ID>-<VERSION STRING>.zip.

Customizing the build process

Aside from just creating the release ZIP there may be additional files you wish to include in your ZIP, other more advanced build processes you want to run such as minifying or concatenating JS or running certain shell commands. All of this can be taken care of in your build.json file. This is a typical build.json file:

    "additional_files": [
    "minify": [
    "rollup": {
        "js/demo/portal/ab-rollup.js": [
    "exec": [
        "echo '{title} version {version_string} ({version_id}) has been built successfully!' > 'src/addons/Demo/Portal/_build/built.txt'"

If you have assets, such as JavaScript, which need to be served outside of your add-on directory, you can tell the build process to copy files or directories using the additional_files array within build.json. During development it isn't always feasible to keep files outside of your add-on directory, so if you prefer, you can keep the files in your add-on _files directory instead. When copying the additional files, we will check there first.

If you ship some JS files with your add-on, you may want to minify those files for performance reasons. You can specify which files you want to minify right inside your build.json. You can list these as an array or you can just specify it as '*' which will just minify everything in your js directory as long as that path has JS files within it after copying the additional files to the build. Any files minified will automatically have a suffix of .min.js instead of .js and the original files will still be in the package.

You may prefer to roll up your multiple JS files into a single file. If you do, you can use the rollup array to define that. The key is the resulting combined filename, and the items within that array are the paths to the JS files that will be combined into a single file.

Finally, you may have certain processes that need to be run just before the package is built and finalised. This could be any combination of things. Ultimately, if it is a command that can be run from the shell (including PHP scripts) then you can specify it here. The example above is of course fairly useless, but it does at least demonstrate that certain placeholders can be used. These placeholders are replaced with scalar values you can get from the XF\AddOn\AddOn object which is generally any value available in the addon.json file, or the AddOn entity.

Development commands

There are actually quite a few development related commands, but only the two most important ones are being covered here.

To use any of these commands, you must have development mode enabled in your config.php file.


Both of the following commands can potentially cause data loss if there is a situation whereby the database and _output directory become out of sync. It is always recommended to use a VCS (Version Control System) such as GitHub to mitigate the impact of such mistakes.

Import development output


$ php cmd.php xf-dev:import --addon [addon_id]

Running this command will import all of the development output files from your add-on _output directory into the database.

Export development output


$ php cmd.php xf-dev:export --addon [addon_id]

This will export all data currently associated to your add-on in the database to files within your _output directory.

Debugging code

It should be possible to set up your favourite debugger tool (XDebug, Zend Debugger etc.) to work with XF2. Though, sometimes, debugging code can be as rudimentary as just quickly seeing what value (or value type) a variable holds at a given time.

Dump a variable

PHP of course has a tool built-in to handle this. You'll likely know it as var_dump(). XF ships with two replacements for this:


The simple version mostly just dumps out the value of a variable in plain text. For example, if you just use it to dump the value of an array, you will see an output at the top of the page like this:

array(2) {
  ["user_id"] => int(1)
  ["username"] => string(5) "Admin"

This is actually the same output as a standard var_dump, but slightly modified for readability and wrapped inside <pre> tags to ensure whitespace is maintained when rendering.

The alternative is actually a component named VarDumper from the Symfony project. It outputs HTML, CSS and JS to create a much more functional and potentially easier to read output. It allows you to collapse certain sections, and for certain values which can output a considerable amount of data, such as objects, it can collapse those sections automatically.