opencolor/src/meta_proxy.js

A collection of functions to parse Open Color files, construct them via code and write them

'use strict'
import ParserError from './parser_error'
import metaValue from './meta_value'

/**
 * @ignore
 */
function makeArrayUnique (inp) { // http://stackoverflow.com/questions/1960473/unique-values-in-an-array
  let a = []
  for (var i = 0, l = inp.length; i < l; i++) {
    if (a.indexOf(inp[i]) === -1) {
      a.push(inp[i])
    }
  }
  return a
}

/**
 * MetaProxy is a way to store and retrieve metadata in various ways
 * Specifically, it handles the fallback to look up metadata on references if the proxy itself
 * doesn't have that data.
 *
 */
export default class MetaProxy {
  /*
   * @param parent reference to the parent object
   */
  constructor (parent) {
    this.parent = parent
    this._hash = {}
    this._data = []
  }
  /**
   * Get a metadatum by key or by index
   * @param {string|number} key key to lookup
   * @return metadatum or undefined.
   * @example
   * metaproxy.get('oct/backgroundColor');
   * @example
   * metaproxy.get(0);
   */
  get (key) {
    let result = null
    if (typeof key === 'string') {
      result = this._hash[key]
    } else {
      result = this._data[key]
    }
    if (!result) {
      if (this.parent.type === 'Reference') {
        result = this.parent.resolved().metadata.get(key)
      }
    }
    return result
  }
  /**
   * Set a metadatum by key
   * @param {string} key
   * @param {string|number|boolean|colorvalue|reference} value
   *
   */
  set (key, value) {
    value = metaValue(value)
    this.addParent(value)
    this._data.push(value)
    this._hash[key] = value
  }

  /**
   * Add self as parent if element is a reference. You probably don't need this.
   * @param {Reference|*} element
   */
  addParent (element) {
    if (element['refName']) {
      element.parent = this.parent
    }
  }

  /**
   * Add metadata by bulk via a hash.
   * @param {object} metadata
   */
  add (metadata) {
    Object.keys(metadata).forEach((key) => {
      if (!key.match(/\//)) {
        throw (new ParserError("Metadata keys must contain at least one slash. (Failed at ''" + key + "')", {}))
      }
      this.set(key, metadata[key])
    }, this)
  }

  /**
   * Get all metadata keys, including keys on references
   * @param {boolean} onlyLocal if true, only local keys will be returned.
   * @return {Array} list of keys
   */
  keys (onlyLocal = false) {
    let localKeys = Object.keys(this._hash)
    let remoteKeys = []
    if (!onlyLocal && this.parent.type === 'Reference') {
      remoteKeys = this.parent.resolved().metadata.keys()
    }
    return makeArrayUnique(localKeys.concat(remoteKeys))
  }
  /**
   * Return a string representation. this only uses local metadata.
   * @return {string} stringified metadata
   */
  toString () {
    return JSON.stringify(this._hash, '  ')
  }
}