Parsers

Eventvisor ships with built in YAML and JSON parsers. You can also provide a custom parser when project definitions use another format.

The built in implementations are published in @eventvisor/parsers and used by the CLI through @eventvisor/core. YAML writes preserve existing comments where possible, including changes made by promotion and other editorial operations.

Built-in parsers#

YAML#

By default, Eventvisor assumes all your definitions are written in YAML and no extra configuration is needed in that case:

module.exports = {
  tags: ['web'],
  // optional if value is "yml"
  parser: 'yml',
}

You can find an example project using YAML here.

JSON#

If we wish to use JSON files instead of YAMLs, we can do so by specifying the parser option:

module.exports = {
  tags: ['web'],
  // define the parser to use
  parser: 'json',
}

You can find an example project using JSON here.

Custom#

If you wish to define your events and attributes in some other language besides YAML and JSON, you can provide your own custom parser.

A parser declares its file extension and provides both parse and stringify functions. Eventvisor passes the current file path as an optional second argument. This allows a parser to preserve comments or formatting when it rewrites an existing definition.

Let's say we wish to use TOML files for our definitions.

We start by installing the @iarna/toml package:

$ npm install --save-dev @iarna/toml

Now we define a custom parser in our configuration:

const TOML = require('@iarna/toml')
module.exports = {
  tags: ['web'],
  parser: {
    extension: 'toml',
    parse: (content) => TOML.parse(content),
    stringify: (content) => TOML.stringify(content),
  },
}