Extract variable references from Handlebars templates.

import barhandles from 'barhandles';

barhandles.extract('{{foo.bar}}', callback);
// Callback will be invoked with ['foo', 'bar'], false

barhandles.extract('{{#with foo}}{{bar}}{{/with}}', callback);
// Callback will be invoked with ['foo', 'bar'], false

barhandles.extract('{{#each foo}}{{bar}}{{/each}}', callback);
// Callback will be invoked with ['foo', '#', 'bar'], false

barhandles.extract('{{#with foo}}{{#each bar}}{{../baz}}{{/each}}{{/with}}', callback);
// Callback will be invoked with ['foo','baz'], false

The second parameter passed to the callback is only present in version 0.4.0 and upwards. It indicates if the field is considered to be optional. Barhandles by default assumes everything is required. Only in case of conditional sections such as when using {{#if}}…{{/if}} it will mark attributs to be optional.

Barhandles also allows you to generate a hierarchical schema from your object model.

barhandlers.extractSchema('{{foo.bar}}');

will produce:

{
  "foo": {
    "_type": "object",
    "_optional": false,
    "bar": {
      "_type": "any",
      "_optional": false
    }
  }
}  

• v0.7.0: Add support for subexpressions, migrate to Typescript
• v0.4.3: Bug fixes
• v0.4.1: Add support for adding behaviour of other directives
• v0.4.0: Support for {{#if}} and optionals.
• v0.3.0: Support for extracting a schema.
• v0.2.0: Initial version