Graphviz Preview

An extension for Visual Studio Code to preview Graphviz (DOT) files.

Installation

You can install this extension from the Visual Studio Marketplace.

This extension requires Graphviz to be installed. Also, make sure that the extension can find the “dot” executable provided by Graphviz. Either make sure the directory containing the “dot” executable exists in the PATH or Path environment variable, or specify the path of the “dot” executable with graphvizPreview.dotPath configuration.

Usage

Open preview

Open the Command Palette (usually by pressing Ctrl + Shift + P), then select “Graphviz: Open Preview to the Side”.

Manipulate preview

There are three zooming modes: Fixed, Fit and Auto Fit.

• Fixed: The zoom ratio does not change when the source changes or the window size changes.
• Fit: The graph is scaled to align to the border of the visible view area.
• Auto Fit: When the view area is big enough to contain a 100% sized graph, the graph will be set a zoom ratio of 100%, otherwise the graph is scaled to fit into the view area.

Export graph

To export the generated graph, click the “Export” button on the top right corner.

Configuration

Make sure the extension can find the “dot” program. You can set graphvizPreview.dotPath option to the path of the dot executable, or make sure the directory containing the dot program is in your PATH environment variable.

To set the graphvizPreview.dotPath option, go to File → Preference → Settings.

Roadmap

• [x] Add border and shadow to indicate the graph border.
• [x] Allow user to save the generated graph.
• [x] Report error if the source is invalid.
• [x] Apply configuration change without restart.
• [x] Allow user to manipulate preview with keyboard.
• [x] Add CI integration.
• [ ] Add animation for zooming.
• [x] Take a new screenshot.
• [ ] Allow user to configure the default zoom mode.
• [x] Add a preview button for source editor.
• [x] Add cancellation support in scheduler.
• [ ] Support previewing source containing multiple graphs.
• [ ] Design a better icon.
• [x] Apply Content Security Policy to webview.
• [x] Support specifying a command-line array for the “dotPath” configuration so that we can use a wrapper for the “dot” program.
• [ ] Fix no-explicit-any errors.
• [ ] Fix no-use-before-define errors.
• [ ] Add focus indicator to preview controls.

Known issues

• After saving an untitled file, the preview becomes invalid.
• When the zoom ratio is too large, the graph may be at a wrong position.

FAQ

• Q: How do I change the layout engine?
  • A: Set graphvizPreview.dotExtraArgs configuration to ["-Glayout=<ENGINE>"], where <ENGINE> is the desired layout engine.