ical.js-one.com/lib/ical/stringify.js

[](http://travis-ci.org/mozilla-comm/ical.js)

ICAL.stringify = (function() {
  'use strict';

  var LINE_ENDING = '\r\n';
  var DEFAULT_TYPE = 'text';

  var design = ICAL.design;
  var helpers = ICAL.helpers;

  /**
   * Convert a full jCal Array into a ical document.
   *
   * @param {Array} jCal document.
   * @return {String} ical document.
   */
  function stringify(jCal) {
    if (!jCal[0] || jCal[0] !== 'icalendar') {
      throw new Error('must provide full jCal document');
    }

    // 1 because we skip the initial element.
    var i = 1;
    var len = jCal.length;
    var result = '';

    for (; i < len; i++) {
      result += stringify.component(jCal[i]) + LINE_ENDING;
    }

    return result;
  }

  /**
   * Converts an jCal component array into a ICAL string.
   * Recursive will resolve sub-components.
   *
   * Exact component/property order is not saved all
   * properties will come before subcomponents.
   *
   * @param {Array} component jCal fragment of a component.
   */
  stringify.component = function(component) {
    var name = component[0].toUpperCase();
    var result = 'BEGIN:' + name + LINE_ENDING;

    var props = component[1];
    var propIdx = 0;
    var propLen = props.length;

    for (; propIdx < propLen; propIdx++) {
      result += stringify.property(props[propIdx]) + LINE_ENDING;
    }

    var comps = component[2];
    var compIdx = 0;
    var compLen = comps.length;

    for (; compIdx < compLen; compIdx++) {
      result += stringify.component(comps[compIdx]) + LINE_ENDING;
    }

    result += 'END:' + name;
    return result;
  }

  /**
   * Converts a single property to a ICAL string.
   *
   * @param {Array} property jCal property.
   */
  stringify.property = function(property) {
    var name = property[0].toUpperCase();
    var jsName = property[0];
    var params = property[1];

    var line = name;

    var paramName;
    for (paramName in params) {
      if (params.hasOwnProperty(paramName)) {
        line += ';' + paramName.toUpperCase();
        line += '=' + stringify.propertyValue(params[paramName]);
      }
    }

    // there is no value so return.
    if (property.length === 3) {
      // if no params where inserted and no value
      // we given we must add a blank value.
      if (!paramName) {
        line += ':';
      }
      return line;
    }

    var valueType = property[2];

    var propDetails;
    var multiValue = false;
    var isDefault = false;

    if (jsName in design.property) {
      propDetails = design.property[jsName];

      if ('multiValue' in propDetails) {
        multiValue = propDetails.multiValue;
      }

      if ('defaultType' in propDetails) {
        if (valueType === propDetails.defaultType) {
          isDefault = true;
        }
      } else {
        if (valueType === DEFAULT_TYPE) {
          isDefault = true;
        }
      }
    } else {
      if (valueType === DEFAULT_TYPE) {
        isDefault = true;
      }
    }

    // push the VALUE property if type is not the default
    // for the current property.
    if (!isDefault) {
      // value will never contain ;/:/, so we don't escape it here.
      line += ';VALUE=' + valueType.toUpperCase();
    }

    line += ':';

    if (multiValue) {
      line += stringify.multiValue(
        property.slice(3), multiValue, valueType
      );
    } else {
      line += stringify.value(property[3], valueType);
    }

    return ICAL.helpers.foldline(line);
  }

  /**
   * Handles escaping of property values that may contain:
   *
   *    COLON (:), SEMICOLON (;), or COMMA (,)
   *
   * If any of the above are present the result is wrapped
   * in double quotes.
   *
   * @param {String} value raw value.
   * @return {String} given or escaped value when needed.
   */
  stringify.propertyValue = function(value) {

    if ((helpers.unescapedIndexOf(value, ',') === -1) &&
        (helpers.unescapedIndexOf(value, ':') === -1) &&
        (helpers.unescapedIndexOf(value, ';') === -1)) {

      return value;
    }

    return '"' + value + '"';
  }

  /**
   * Converts an array of ical values into a single
   * string based on a type and a delimiter value (like ",").
   *
   * @param {Array} values list of values to convert.
   * @param {String} delim used to join the values usually (",", ";", ":").
   * @param {String} type lowecase ical value type
   *  (like boolean, date-time, etc..).
   *
   * @return {String} ical string for value.
   */
  stringify.multiValue = function(values, delim, type) {
    var result = '';
    var len = values.length;
    var i = 0;

    for (; i < len; i++) {
      result += stringify.value(values[i], type);
      if (i !== (len - 1)) {
        result += delim;
      }
    }

    return result;
  }

  /**
   * Processes a single ical value runs the associated "toICAL"
   * method from the design value type if available to convert
   * the value.
   *
   * @param {String|Numeric} value some formatted value.
   * @param {String} type lowecase ical value type
   *  (like boolean, date-time, etc..).
   * @return {String} ical value for single value.
   */
  stringify.value = function(value, type) {
    if (type in design.value && 'toICAL' in design.value[type]) {
      return design.value[type].toICAL(value);
    }
    return value;
  }

  return stringify;

}());