messageFormatSelector.js

'use strict';

// NOTE: ADVANCED_OPTIMIZATIONS mode.
//
// This file is compiled with Closure compiler's ADVANCED_OPTIMIZATIONS flag! Be wary of using
// constructs incompatible with that mode.

/* global $interpolateMinErr: false */
/* global isFunction: false */
/* global noop: false */

/**
 * @constructor
 * @private
 */
function MessageSelectorBase(expressionFn, choices) {
  var self = this;
  this.expressionFn = expressionFn;
  this.choices = choices;
  if (choices['other'] === undefined) {
    throw $interpolateMinErr('reqother', '“other” is a required option.');
  }
  this.parsedFn = function(context) { return self.getResult(context); };
  this.parsedFn['$$watchDelegate'] = function $$watchDelegate(scope, listener, objectEquality) {
    return self.watchDelegate(scope, listener, objectEquality);
  };
  this.parsedFn['exp'] = expressionFn['exp'];
  this.parsedFn['expressions'] = expressionFn['expressions'];
}

MessageSelectorBase.prototype.getMessageFn = function getMessageFn(value) {
  return this.choices[this.categorizeValue(value)];
};

MessageSelectorBase.prototype.getResult = function getResult(context) {
  return this.getMessageFn(this.expressionFn(context))(context);
};

MessageSelectorBase.prototype.watchDelegate = function watchDelegate(scope, listener, objectEquality) {
  var watchers = new MessageSelectorWatchers(this, scope, listener, objectEquality);
  return function() { watchers.cancelWatch(); };
};

/**
 * @constructor
 * @private
 */
function MessageSelectorWatchers(msgSelector, scope, listener, objectEquality) {
  var self = this;
  this.scope = scope;
  this.msgSelector = msgSelector;
  this.listener = listener;
  this.objectEquality = objectEquality;
  this.lastMessage = undefined;
  this.messageFnWatcher = noop;
  var expressionFnListener = function(newValue, oldValue) { return self.expressionFnListener(newValue, oldValue); };
  this.expressionFnWatcher = scope['$watch'](msgSelector.expressionFn, expressionFnListener, objectEquality);
}

MessageSelectorWatchers.prototype.expressionFnListener = function expressionFnListener(newValue, oldValue) {
  var self = this;
  this.messageFnWatcher();
  var messageFnListener = function(newMessage, oldMessage) { return self.messageFnListener(newMessage, oldMessage); };
  var messageFn = this.msgSelector.getMessageFn(newValue);
  this.messageFnWatcher = this.scope['$watch'](messageFn, messageFnListener, this.objectEquality);
};

MessageSelectorWatchers.prototype.messageFnListener = function messageFnListener(newMessage, oldMessage) {
  if (isFunction(this.listener)) {
    this.listener.call(null, newMessage, newMessage === oldMessage ? newMessage : this.lastMessage, this.scope);
  }
  this.lastMessage = newMessage;
};

MessageSelectorWatchers.prototype.cancelWatch = function cancelWatch() {
  this.expressionFnWatcher();
  this.messageFnWatcher();
};

/**
 * @constructor
 * @extends MessageSelectorBase
 * @private
 */
function SelectMessage(expressionFn, choices) {
  MessageSelectorBase.call(this, expressionFn, choices);
}

function SelectMessageProto() {}
SelectMessageProto.prototype = MessageSelectorBase.prototype;

SelectMessage.prototype = new SelectMessageProto();
SelectMessage.prototype.categorizeValue = function categorizeSelectValue(value) {
  return (this.choices[value] !== undefined) ? value : 'other';
};

/**
 * @constructor
 * @extends MessageSelectorBase
 * @private
 */
function PluralMessage(expressionFn, choices, offset, pluralCat) {
  MessageSelectorBase.call(this, expressionFn, choices);
  this.offset = offset;
  this.pluralCat = pluralCat;
}

function PluralMessageProto() {}
PluralMessageProto.prototype = MessageSelectorBase.prototype;

PluralMessage.prototype = new PluralMessageProto();
PluralMessage.prototype.categorizeValue = function categorizePluralValue(value) {
  if (isNaN(value)) {
    return 'other';
  } else if (this.choices[value] !== undefined) {
    return value;
  } else {
    var category = this.pluralCat(value - this.offset);
    return (this.choices[category] !== undefined) ? category : 'other';
  }
};