check.jcarr.wit.com/chrome/load_time_data.js

213 lines
7.2 KiB
JavaScript

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/**
* @fileoverview This file defines a singleton which provides access to all data
* that is available as soon as the page's resources are loaded (before DOM
* content has finished loading). This data includes both localized strings and
* any data that is important to have ready from a very early stage (e.g. things
* that must be displayed right away).
*
* Note that loadTimeData is not guaranteed to be consistent between page
* refreshes (https://crbug.com/740629) and should not contain values that might
* change if the page is re-opened later.
*/
/** @type {!LoadTimeData} */ var loadTimeData;
// Expose this type globally as a temporary work around until
// https://github.com/google/closure-compiler/issues/544 is fixed.
/** @constructor */
function LoadTimeData(){}
(function() {
'use strict';
LoadTimeData.prototype = {
/**
* Sets the backing object.
*
* Note that there is no getter for |data_| to discourage abuse of the form:
*
* var value = loadTimeData.data()['key'];
*
* @param {Object} value The de-serialized page data.
*/
set data(value) {
expect(!this.data_, 'Re-setting data.');
this.data_ = value;
},
/**
* Returns a JsEvalContext for |data_|.
* @returns {JsEvalContext}
*/
createJsEvalContext: function() {
return new JsEvalContext(this.data_);
},
/**
* @param {string} id An ID of a value that might exist.
* @return {boolean} True if |id| is a key in the dictionary.
*/
valueExists: function(id) {
return id in this.data_;
},
/**
* Fetches a value, expecting that it exists.
* @param {string} id The key that identifies the desired value.
* @return {*} The corresponding value.
*/
getValue: function(id) {
expect(this.data_, 'No data. Did you remember to include strings.js?');
var value = this.data_[id];
expect(typeof value != 'undefined', 'Could not find value for ' + id);
return value;
},
/**
* As above, but also makes sure that the value is a string.
* @param {string} id The key that identifies the desired string.
* @return {string} The corresponding string value.
*/
getString: function(id) {
var value = this.getValue(id);
expectIsType(id, value, 'string');
return /** @type {string} */ (value);
},
/**
* Returns a formatted localized string where $1 to $9 are replaced by the
* second to the tenth argument.
* @param {string} id The ID of the string we want.
* @param {...(string|number)} var_args The extra values to include in the
* formatted output.
* @return {string} The formatted string.
*/
getStringF: function(id, var_args) {
var value = this.getString(id);
if (!value)
return '';
var args = Array.prototype.slice.call(arguments);
args[0] = value;
return this.substituteString.apply(this, args);
},
/**
* Returns a formatted localized string where $1 to $9 are replaced by the
* second to the tenth argument. Any standalone $ signs must be escaped as
* $$.
* @param {string} label The label to substitute through.
* This is not an resource ID.
* @param {...(string|number)} var_args The extra values to include in the
* formatted output.
* @return {string} The formatted string.
*/
substituteString: function(label, var_args) {
var varArgs = arguments;
return label.replace(/\$(.|$|\n)/g, function(m) {
assert(m.match(/\$[$1-9]/), 'Unescaped $ found in localized string.');
return m == '$$' ? '$' : varArgs[m[1]];
});
},
/**
* Returns a formatted string where $1 to $9 are replaced by the second to
* tenth argument, split apart into a list of pieces describing how the
* substitution was performed. Any standalone $ signs must be escaped as $$.
* @param {string} label A localized string to substitute through.
* This is not an resource ID.
* @param {...(string|number)} var_args The extra values to include in the
* formatted output.
* @return {!Array<!{value: string, arg: (null|string)}>} The formatted
* string pieces.
*/
getSubstitutedStringPieces: function(label, var_args) {
var varArgs = arguments;
// Split the string by separately matching all occurrences of $1-9 and of
// non $1-9 pieces.
var pieces = (label.match(/(\$[1-9])|(([^$]|\$([^1-9]|$))+)/g) ||
[]).map(function(p) {
// Pieces that are not $1-9 should be returned after replacing $$
// with $.
if (!p.match(/^\$[1-9]$/)) {
assert(
(p.match(/\$/g) || []).length % 2 == 0,
'Unescaped $ found in localized string.');
return {value: p.replace(/\$\$/g, '$'), arg: null};
}
// Otherwise, return the substitution value.
return {value: varArgs[p[1]], arg: p};
});
return pieces;
},
/**
* As above, but also makes sure that the value is a boolean.
* @param {string} id The key that identifies the desired boolean.
* @return {boolean} The corresponding boolean value.
*/
getBoolean: function(id) {
var value = this.getValue(id);
expectIsType(id, value, 'boolean');
return /** @type {boolean} */ (value);
},
/**
* As above, but also makes sure that the value is an integer.
* @param {string} id The key that identifies the desired number.
* @return {number} The corresponding number value.
*/
getInteger: function(id) {
var value = this.getValue(id);
expectIsType(id, value, 'number');
expect(value == Math.floor(value), 'Number isn\'t integer: ' + value);
return /** @type {number} */ (value);
},
/**
* Override values in loadTimeData with the values found in |replacements|.
* @param {Object} replacements The dictionary object of keys to replace.
*/
overrideValues: function(replacements) {
expect(
typeof replacements == 'object',
'Replacements must be a dictionary object.');
for (var key in replacements) {
this.data_[key] = replacements[key];
}
}
};
/**
* Checks condition, displays error message if expectation fails.
* @param {*} condition The condition to check for truthiness.
* @param {string} message The message to display if the check fails.
*/
function expect(condition, message) {
if (!condition) {
console.error(
'Unexpected condition on ' + document.location.href + ': ' + message);
}
}
/**
* Checks that the given value has the given type.
* @param {string} id The id of the value (only used for error message).
* @param {*} value The value to check the type on.
* @param {string} type The type we expect |value| to be.
*/
function expectIsType(id, value, type) {
expect(
typeof value == type, '[' + value + '] (' + id + ') is not a ' + type);
}
expect(!loadTimeData, 'should only include this file once');
loadTimeData = new LoadTimeData;
})();