sphinxcontrib-drawio

Sphinx Extension adding the drawio-image and drawio-figure directives. These are equivalent to the standard image and figure directives, but accept the path to a .drawio file and additional options to control exporting of the diagram to a suitable image format.

Important: This extension does not work on readthedocs as RTD does not allow packages (e.g. drawio) to be installed. If you only require diagrams in a single format, you can consider using 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 configuration option to auto.

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

Installation

1. python3 -m pip install sphinxcontrib-drawio

2. In your sphinx config, add:

   extensions = [
       "sphinxcontrib.drawio"
   ]
   

3. Add the draw.io binary to $PATH. See Options: Binary Path for more details and alternative solutions.

4. If running headless, install Xvfb, e.g. via $ sudo apt install xvfb.

Options

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

Binary Path

• Formal Name: drawio_binary_path
• Default Value: None

This allows for a specific override for the binary location. By default, this chooses the drawio (or draw.io.exe) binary accessible in $PATH. However, if this file does not exist, it picks the platform-appropriate path:

• Windows: C:\Program Files\draw.io\draw.io.exe
• Linux: /opt/drawio/drawio or /opt/draw.io/drawio (older versions)
• MacOS: /Applications/draw.io.app/Contents/MacOS/draw.io.

Headless Mode

• 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.

Default Output Format

• Formal Name: drawio_builder_export_format
• Default Value: {}

This config option controls the default export file format for each Sphinx builder. It accepts a dictionary mapping builder names to image formats. The builder name should match the name of a Sphinx builder (e.g., "html", "latex"). Accepted values for the export format are "png", "jpg", "svg" and "pdf". If no format is set for a given builder, its preferred image format is used, that is, the first format listed in a builder's supported_image_types that draw.io is capable of exporting to (eg. SVG for HTML, PDF for LaTeX).

Default Export Scale

• Formal Name: drawio_default_export_scale
• Default Value: 100
• Possible Values: any positive integer

This config option sets the default export scale for all diagrams. This scales the size of the diagram. So if you take a diagram that by default would output a image with a resolution of 50x50 pixels and a scale of 200, you will obtain an image with a resolution that is approximately 100x100 pixels. By default draw.io usually outputs relatively low resolution images, so 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 export-width or export-height are set for an image, this option will have no effect on the generated image.

Default Transparency

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

This changes the background transparency for diagrams exported in png format. This will be overridden if the transparency is set for a individual diagram in the directive. If the output format isn't png, it will not affect the image exported.

Disable Verbose Electron

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

Electron's verbose logging is turned on by default to help troubleshoot certain errors produced by the drawio app, but can be disabled if it causes a logging conflict. This option only affects the output when the drawio app errors. See the Electron docs for more info.

Disable Shared Memory Usage

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

By default, Docker runs a container with a /dev/shm shared memory space of 64MB. This is typically too small for Chrome (Electron) and will cause Chrome to throw an error. Launching the browser with the --disable-dev-shm-usage flag will write shared memory files into /tmp instead of /dev/shm.

Disable GPU

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

By default, Chrome (Electron) uses GPU processes which can cause errors when running in environments that are not set up for it. This option disables those GPU processes and uses the CPU instead.

No Sandbox

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

This option may be needed to work in a docker container. You should probably only enable it if you are experiencing issues. See https://github.com/jgraph/drawio-desktop/issues/144 for more info.

Usage

The extension can be used through the drawio-image directive. For example:

.. drawio-image:: example.drawio
   :export-scale: 150

There's also a drawio-figure directive that mimics the figure directive:

.. drawio-figure:: example.drawio
   :format: png

   An example diagram

The directives can be configured with options to control the export of the draw.io diagram to a bitmap or vector image. These options are documented below.

Additionally, drawio-image accepts all of the options supported by the image directive. These options apply to the image as exported by draw.io. Similarly, drawio-figure accepts all options supported by the figure directive.

Format

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

This option controls the output file format of this specific directive.

Page Index

• 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 export. Note that an invalid page-index will revert to one of the other valid pages (draw.io binary functionality). page-name and page-index cannot coexist, if you set both options, an error will be reported.

Page Name

• Formal Name: :page-name:
• Default Value: value of :page-index:, else the first page
• Possible Values: any string

This option allows you to select a particular page by its name from a draw.io file to export. page-name and page-index cannot coexist, if you set both options, an error will be reported. If :page-name: is not found in the draw.io file, an error will be reported too.

Export Scale

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

This 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 pixels and a scale of 200, you will obtain an image with a resolution that is approximately 100x100 pixels. By default draw.io usually outputs relatively low-resolution images, so this setting can be used to remedy that. This overrides the drawio_default_export_scale set in conf.py for this specific diagram. If either export-width or export-height are set for a given image, export-scale will have no effect on the generated image.

Export Width

• Formal Name: :export-width:
• Possible Values: any positive integer

This fits the generated image into the specified width, preserving aspect ratio. When exporting to a bitmap image, this specifies the width in pixels. For PDF, a value of 100 corresponds to 1.00 inches.

Export Height

• Formal Name: :export-height:
• Possible Values: any positive integer

This fits the generated image into the specified height, preserving aspect ratio. When exporting to a bitmap image, this specifies the height in pixels. For PDF, a value of 100 corresponds to 1.00 inches.

Transparency

• 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 set 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