Sphinx Extension to add the drawio directive to include draw.io diagrams.

Important: This extension does not work on readthedocs as RTD does not allow packages (e.g. drawio) to be installed. It would be better to use editable SVGs or PNGs, accessible through draw.io's File > Export menu.

The drawio-desktop package does not run without an x-server (e.g. when in a CI environment), see this issue. The workaround is to install xvfb and set the drawio_headless config to auto.

If any other of the draw.io CLI tool's options are wanted, please file an issue.

1. python3 -m pip install sphinxcontrib-drawio
2. In your sphinx config:

extensions = [
    "sphinxcontrib.drawio"
]

3. Add the binary to $PATH. For Windows add C:\Program Files\draw.io and on Linux add /opt/draw.io/.
4. (if running headless), sudo apt install xvfb

These values are placed in the conf.py of your sphinx project.

• Formal Name: drawio_output_format
• Default Value: "png"
• Possible Values: "png", "jpg", or "svg"

This config option controls the output file format which will be placed inside the generated HTML. More file formats are available but not exposed, please file an issue if you wish to add another file format.

This value is ignored in PDF (LaTeX) output, instead always using the PDF output format.

• Formal Name: drawio_binary_path
• Default Value: None

This allows for a specific override for the binary location. By default, this gets chosen depending on the OS (Linux, Mac, or Windows) to the default install path of the draw.io program.

• Formal Name: drawio_headless
• Default Value: "auto"
• Possible Values: True, False, or "auto"

This config option controls the behaviour of running the Xvfb server. It is necessary because draw.io will not work without an X-server, see this issue.

The auto mode will detect whether the program is running in a headless environment through the $DISPLAY environment variable, and act as if it were set to True. If not running on Linux, or the $DISPLAY environment variable contains some value (i.e. running in an X-server on a developer's machine), it will act as it it were set to False.

Setting the value to True will start a virtual X framebuffer through the Xvfb command before running any draw.io commands, and stop it afterwards.

Setting the value to False will run the draw.io binary as normal.

• Formal Name: drawio_default_scale
• Default Value: 1

This config option sets the default scale for all diagrams. This simply scales the size of the diagram. So if you take a diagram that by default would output a image with a resolution of 50x50 and a scale of 2, you will get a image with a resolution that is approximately 100x100. By default draw.io usually outputs relatively low resolution images, this setting can be used to remedy that. This setting will get automatically overridden if the scale is set for a individual diagram in the directive. If either width or height are set for a image, scale will have no effect on the generated image.

• Formal Name: drawio_default_transparency
• Default Value: False
• Possible Values: True or False

This changes the background transparency for diagrams exported to png files. Will get overridden if the transparency is set for a individual diagram in the directive. If the output format isn't png, it will not effect the image generated.

The extension can be used through the drawio directive, as per below:

.. drawio:: example.drawio

The directive can also be configured with a variety of options. Most of these options are ignored as they do not work in PDF output.

• Formal Name: :format:
• Default Value: "png"
• Possible Values: "png", "jpg", or "svg"

This option controls the output file format of this specific directive. It provides similar functionality to that of the drawio_output_format config option but at a more granular level.

This value is ignored in PDF (LaTeX) output, instead always using the PDF output format.

• Formal Name: :alt:

This option sets the img tag's alt attribute. For more information on its functionality, see the Mozilla web documentation.

• Formal Name: :align:
• Possible Values: "left", "center", or "right"

This option allows control over the alignment of the image on the page.

• Formal Name: :page-index:
• Default Value: 0
• Possible Values: any integer

This option allows you to select a particular page from a draw.io file to create the image from. Note: an invalid page-index will revert to one of the other valid pages (draw.io binary functionality)

• Formal Name: :scale:
• Default Value: drawio_default_scale set in conf.py
• Possible Values: any positive integer

This simply scales the size of the output image. So if you take a diagram that by default would output a image with a resolution of 50x50 and a scale of 2, you will get a image with a resolution that is approximately 100x100. By default draw.io usually outputs relatively low resolution images, this setting can be used to remedy that. This overrides the drawio_default_scale set in conf.py for this specific diagram. If either width or height are set for a given image, scale will have no effect on the generated image.

• Formal Name: :transparency:
• Default Value: drawio_default_transparency set in conf.py
• Possible Values: "true" or "false"

This changes the background transparency for diagrams exported to png files. Will override drawio_default_transparency which was st in conf.py for this specific diagram. If this setting is specified while the output format is not png it will have no effect on the generated image