@emmetio/abbreviation

Emmet standalone abbreviation parser

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4,04658May 11, 2021Feb 15, 2010Minified + gzip package size for @emmetio/abbreviation in KB

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Emmet markup abbreviation parser

Parses given Emmet markup abbreviation into AST. Parsing is performed in two steps: first it tokenizes given abbreviation (useful for syntax highlighting in editors) and then tokens are analyzed and converted into AST nodes as plain, JSON-serializable objects.

Note that AST tree in most cases cannot be used directly for output: for example, AST node produced from .foo.bar element misses element name and contains two class attributes with foo and bar values (not a single class with foo bar value).

Usage

You can install it via npm:

npm install @emmetio/abbreviation

Then add it into your project:

import parse from '@emmetio/abbreviation';

const tree = parse('div#foo>span.bar*3');
/* {
    type: 'Abbreviation',
    children: [{
        type: 'AbbreviationNode',
        name: 'div',
        attributes: [...],
        children: [...]
    }]
} */

The returned tree contains AbbreviationNode items: a node with name, attributes and/or text content. E.g. an element that can be represented somehow. Repeated and grouped nodes like a>(b+c)*3 are automatically converted and duplicated as distinct AbbreviationNode with distinct .repeat property which identifies node in repeating sequence.

Abbreviation syntax

Emmet abbreviation element has the following basic parts:

name.class#id[attributes?, ...]{text value}*repeater/
  • name β€” element name, like div, span etc. Stored as node.name property.
  • [attributes] β€” list of attributes. Each attribute is stored as AbbreviationAttribute instance and can be accessed by node.getAttribute(name). Each attribute can be written in different formats:
    • attr β€” attribute with empty value.
    • attr=value β€” attribute with value. The value may contain any character except space or ].
    • attr="value" or attr='value' β€” attribute with value in quotes. Quotes are automatically removed. Expression values like attr={value} are supported and can be identified by valueType: "expression" property.
    • attr. β€” boolean attribute, e.g. attribute without value, like required in <input>.
    • !attr – implicit attribute, will be outputted if its value is not empty. Used as a placeholder to preserve attribute order in output.
    • ./non/attr/value β€” value for default attribute. In other words, anything that doesn’t match a attribute name characters. Can be a single- or double-quotted as well. Default attribute is stored with null as name and should be used later, for example, to resolve predefined attributes.
  • .class β€” shorthand for class attribute. Note that an element can have multiple classes, like .class1.class2.class3.
  • #id β€” shorthand for id attribute.
  • {text} β€” node’s text content
  • *N β€” element repeater, tells parser to create N copies of given node.
  • / β€” optional self-closing operator. Marks element with node.selfClosing = true.

Operators

Each element of abbreviation must be separated with any of these operators:

elem1+elem2>elem3
  • + β€” sibling operator, adds next element as a next sibling of current element in tree.
  • > β€” child operator, adds next element as a child of current element.
  • ^ β€” climb-up operator, adds next element as a child of current element’s parent node. Multiple climb-up operators are allowed, each operator moves one level up by tree.

Groups

A set of elements could be grouped using (), mostly for repeating and for easier elements nesting:

a>(b>c+d)*4+(e+f)

Groups can be optionally concatenated with + operator.

If you find any bugs or have a feature request, please open an issue on github!

The npm package download data comes from npm's download counts api and package details come from npms.io.