Method performTranslate

src/Encoder/SpellingAlphabet.js:162–196

* Performs encode or decode on given content. * @protected * @param {Chain} content * @param {boolean} isEncode True for encoding, false for decoding * @return {number[]|string|Uint8Array|Chain|Promise} Resulting content

(content, isEncode)

   * @return {number[]|string|Uint8Array|Chain|Promise} Resulting content
   */
  performTranslate (content, isEncode) {
    // Retrieve content string and normalize its whitespaces
    const string = StringUtil.normalizeWhitespaces(content.getString())

    // Alphabet characters
    const replacementMap = isEncode ? this._characterMap : this._wordMap
    const searchValues =
      Object.keys(replacementMap).sort((a, b) => b.length - a.length)

    let index = 0
    const resultValues = []

    while (index < string.length) {
      // Find next occurance in string
      const searchValue = searchValues.find(value =>
        string.substr(index, value.length).toLowerCase() === value.toLowerCase())

      if (searchValue !== undefined) {
        // Append char (in encode mode) or word (in decode mode) to result
        resultValues.push(replacementMap[searchValue])
        index += searchValue.length
      } else {
        const char = string.substr(index, 1)
        // Omit whitespaces when decoding
        if (isEncode || char !== ' ') {
          // Append foreign character to result
          resultValues.push(char)
        }
        index++
      }
    }

    // String together result
    return resultValues.join(isEncode ? ' ' : '')
  }

  /**
   * Triggered when a setting field has changed.