@marp-team/marpit/lib/helpers/inline_style.js

The skinny framework for creating slide deck from Markdown

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _postcss = _interopRequireDefault(require("postcss"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } return target; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

/**
 * InlineStyle helper class.
 *
 * This is the declarative builder of an inline style using PostCSS. The output
 * string by `toString()` is sanitized unexpected declarations.
 *
 * @module
 * @alias module:helpers/inline_style
 */
class InlineStyle {
  /**
   * Create an InlineStyle instance.
   *
   * @function constructor
   * @param {Object|String|InlineStyle} [initialDecls] The initial declarations.
   */
  constructor(initialDecls) {
    this.decls = {};

    if (initialDecls) {
      if (initialDecls instanceof InlineStyle || typeof initialDecls === 'string') {
        const root = _postcss.default.parse(initialDecls.toString(), {
          from: undefined
        });

        root.each(node => {
          if (node.type === 'decl') this.decls[node.prop] = node.value;
        });
      } else {
        this.decls = _objectSpread({}, initialDecls);
      }
    }
  }
  /**
   * Delete declaration.
   *
   * @param {string} prop A property name of declaration.
   * @returns {InlineStyle} Returns myself for chaining methods.
   */


  delete(prop) {
    delete this.decls[prop];
    return this;
  }
  /**
   * Set declaration.
   *
   * @param {string} prop A property name of declaration.
   * @param {string} value A value of declaration.
   * @returns {InlineStyle} Returns myself for chaining methods.
   */


  set(prop, value) {
    this.decls[prop] = value;
    return this;
  }
  /**
   * Build a string of declarations for the inline style.
   *
   * The unexpected declarations will strip to prevent a style injection.
   */


  toString() {
    let built = '';

    for (const prop of Object.keys(this.decls)) {
      let parsed;

      try {
        parsed = _postcss.default.parse(`${prop}:${this.decls[prop]}`, {
          from: undefined
        });
      } catch (e) {// A declaration that have value it cannot parse will ignore.
      }

      if (parsed) {
        parsed.each(node => {
          if (node.type !== 'decl' || node.prop !== prop) node.remove();
        });
        built += `${parsed.toString()};`;
      }
    }

    return built;
  }

}

exports.default = InlineStyle;