Writing New Templates

MultiQC is built around a templating system that uses the Jinja python package. This makes it very easy to create new report templates that fit your needs.

Core or plugin

If your template could be of use to others, it would be great if you could add it to the main MultiQC package. You can do this by creating a fork of the MultiQC GitHub repository, adding your template and then creating a pull request to merge your changes back to the main repository.

If it’s very specific template, you can create a new Python package which acts as a plugin. For more information about this, see the plugins documentation.

Creating a template skeleton

For a new template to be recognised by MultiQC, it must be a python submodule directory with a __init__.py file. This must be referenced in the setup.py installation script as an entry point.

You can see the bundled templates defined in this way:

entry_points = {
    'multiqc.templates.v1': [
        'default = multiqc.templates.default',
        'simple = multiqc.templates.simple',
        'geo = multiqc.templates.geo',
    ]
}

Note that these entry points can point to any Python modules, so if you’re writing a plugin module you can specify your module name instead. Just make sure that multiqc.templates.v1 is the same.

Once you’ve added the entry point, remember to install the package again:

pip install -e .

Using -e tells pip to softlink the plugin files instead of copying, so changes made whilst editing files will be reflected when you run MultiQC.

The __init__.py files must define two variables - the path to the template directory and the main jinja template file:

template_dir = os.path.dirname(__file__)
base_fn = 'base.html'

Child templates

The default MultiQC template contains a lot of code. Importantly, it includes 1448 lines of custom JavaScript (at time of writing) which powers the plotting and dynamic functions in the report. You probably don’t want to rewrite all of this for your template, so to make your life easier you can create a child template.

To do this, add an extra variable to your template’s __init__.py:

template_parent = 'default'

This tells MultiQC to use the template files from the default template unless a file with the same name is found in your child template. For instance, if you just want to add your own logo in the header of the reports, you can create your own header.html which will overwrite the default header.

Files within the default template have comments at the top explaining what part of the report they generate.

Extra init variables

There are a few extra variables that can be added to the __init__.py file to change how the report is generated.

Setting output_dir instructs MultiQC to put the report and it’s contents into a subdirectory. Set the string to your desired name. Note that this will be prefixed if -p/--prefix is set at run time.

Secondly, you can copy additional files with your report when it is generated. This is usually used to copy required images or scripts with the report. These should be a list of file or directory paths, relative to the __init__.py file. Directory contents will be copied recursively.

You can also override config options in the template. For example, setting the value of config.plots_force_flat can force the report to only have static image plots.

from multiqc.utils import config
 
output_subdir = 'multiqc_report'
copy_files = ['assets']
config.plots_force_flat = True

Jinja template variables

There are a number of variables that you can use within your Jinja template. Two namespaces are available - report and config. You can print these using the Jinja curly brace syntax, eg. {{ config.version }}. See the Jinja2 documentation for more information.

The default MultiQC template includes dependencies in the HTML so that the report is standalone. If you would like to do the same, use the include_file function. For example:

<script>
  {
    {
      include_file("js/jquery.min.js");
    }
  }
</script>
<img src="data:image/png;base64,{{ include_file('img/logo.png', b64=True) }}" />

Appendices

Custom plotting functions

If you don’t like the default plotting functions built into MultiQC, you can write your own! If you create a callable variable in a template called either bargraph or linegraph, MultiQC will use that instead. For example:

def custom_linegraph(plotdata, pconfig):
    return '<h1>Awesome line graph here</h1>'
linegraph = custom_linegraph
 
def custom_bargraph(plotdata, plotseries, pconfig):
    return '<h1>Awesome bar graph here</h1>'
bargraph = custom_bargraph

These particular examples don’t do very much, but hopefully you get the idea. Note that you have to set the variable linegraph or bargraph to your function.