postcss-rs / astexplorer

A web tool to explore the ASTs generated by various parsers.

CSS AST explorer

The ast explorer is not active since 2021/8/22, this fork just update postcss to the latest version for better debug experence

Paste or drop css code into the editor and inspect the generated AST on https://postcss-rs.github.io/astexplorer/

The AST explorer provides following css parsers:

• [cssom][]
• [csstree][]
• [postcss][] + [postcss-safe-parser][] & [postcss-scss][]
• [rework][]

Transforms

Since future syntax is supported, the AST explorer is a useful tool for developers who want to create AST transforms. In fact, following transformers are included so you can prototype your own plugins:

• [postcss][]

How to add a new parser

1. Go to website/.
2. Install the new parser as dependency: yarn add theParser (or npm install -S theParser)
3. Copy one of the existing examples in src/parsers/{language}.
4. Adjust the code as necessary:

• Update metadata.
• Load the right parser (loadParser).
• Call the right parsing method with the right/necessary options in parse.
• Implement the nodeToRange method (this is for highlighting).
• Implement the getNodeName method (this is for quick look through the tree).
• Implement opensByDefault method for auto-expansion of specific properties.
• Define _ignoredProperties set or implement forEachProperty generator method for filtering.
• Provide a renderSettings method if applicable.

How to add a new transformer

0. Go to website/.
1. Install the new transformer as dependency.
2. Copy one of the existing examples in src/parsers/{language}/transformers.
3. Adjust the code as necessary:

• Update metadata and defaultParserID.
• Load the right transformer (loadTransformer).
• Call the transformation method in transform.
• Change sample transformation code in codeExample.txt.

Build your own version for development

1. Clone the repository.
2. Go to website/.
3. Install all dependencies with yarn install (you can run npm install as well).

Run yarn run build for the final minimized version. Run yarn run watch for incremental builds.

Run yarn start to start a simple static webserver.