lodash/lodash.template/index.js

/**
 * lodash 4.1.1 (Custom Build) <https://lodash.com/>
 * Build: `lodash modularize exports="npm" -o ./`
 * Copyright 2012-2016 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2016 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <https://lodash.com/license>
 */
var arrayMap = require('lodash._arraymap'),
    assignInWith = require('lodash.assigninwith'),
    keys = require('lodash.keys'),
    reInterpolate = require('lodash._reinterpolate'),
    rest = require('lodash.rest'),
    templateSettings = require('lodash.templatesettings'),
    toString = require('lodash.tostring');

/** Used as references for various `Number` constants. */
var MAX_SAFE_INTEGER = 9007199254740991;

/** `Object#toString` result references. */
var errorTag = '[object Error]',
    funcTag = '[object Function]',
    genTag = '[object GeneratorFunction]';

/** Used to match empty string literals in compiled template source. */
var reEmptyStringLeading = /\b__p \+= '';/g,
    reEmptyStringMiddle = /\b(__p \+=) '' \+/g,
    reEmptyStringTrailing = /(__e\(.*?\)|\b__t\)) \+\n'';/g;

/** Used to match [ES template delimiters](http://ecma-international.org/ecma-262/6.0/#sec-template-literal-lexical-components). */
var reEsTemplate = /\$\{([^\\}]*(?:\\.[^\\}]*)*)\}/g;

/** Used to detect unsigned integer values. */
var reIsUint = /^(?:0|[1-9]\d*)$/;

/** Used to ensure capturing order of template delimiters. */
var reNoMatch = /($^)/;

/** Used to match unescaped characters in compiled string literals. */
var reUnescapedString = /['\n\r\u2028\u2029\\]/g;

/** Used to escape characters for inclusion in compiled string literals. */
var stringEscapes = {
  '\\': '\\',
  "'": "'",
  '\n': 'n',
  '\r': 'r',
  '\u2028': 'u2028',
  '\u2029': 'u2029'
};

/**
 * A faster alternative to `Function#apply`, this function invokes `func`
 * with the `this` binding of `thisArg` and the arguments of `args`.
 *
 * @private
 * @param {Function} func The function to invoke.
 * @param {*} thisArg The `this` binding of `func`.
 * @param {...*} args The arguments to invoke `func` with.
 * @returns {*} Returns the result of `func`.
 */
function apply(func, thisArg, args) {
  var length = args.length;
  switch (length) {
    case 0: return func.call(thisArg);
    case 1: return func.call(thisArg, args[0]);
    case 2: return func.call(thisArg, args[0], args[1]);
    case 3: return func.call(thisArg, args[0], args[1], args[2]);
  }
  return func.apply(thisArg, args);
}

/**
 * The base implementation of `_.values` and `_.valuesIn` which creates an
 * array of `object` property values corresponding to the property names
 * of `props`.
 *
 * @private
 * @param {Object} object The object to query.
 * @param {Array} props The property names to get values for.
 * @returns {Object} Returns the array of property values.
 */
function baseValues(object, props) {
  return arrayMap(props, function(key) {
    return object[key];
  });
}

/**
 * Used by `_.template` to escape characters for inclusion in compiled string literals.
 *
 * @private
 * @param {string} chr The matched character to escape.
 * @returns {string} Returns the escaped character.
 */
function escapeStringChar(chr) {
  return '\\' + stringEscapes[chr];
}

/**
 * Checks if `value` is a valid array-like index.
 *
 * @private
 * @param {*} value The value to check.
 * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
 * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
 */
function isIndex(value, length) {
  value = (typeof value == 'number' || reIsUint.test(value)) ? +value : -1;
  length = length == null ? MAX_SAFE_INTEGER : length;
  return value > -1 && value % 1 == 0 && value < length;
}

/** Used for built-in method references. */
var objectProto = Object.prototype;

/** Used to check objects for own properties. */
var hasOwnProperty = objectProto.hasOwnProperty;

/**
 * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
 * of values.
 */
var objectToString = objectProto.toString;

/**
 * Used by `_.defaults` to customize its `_.assignIn` use.
 *
 * @private
 * @param {*} objValue The destination value.
 * @param {*} srcValue The source value.
 * @param {string} key The key of the property to assign.
 * @param {Object} object The parent object of `objValue`.
 * @returns {*} Returns the value to assign.
 */
function assignInDefaults(objValue, srcValue, key, object) {
  if (objValue === undefined ||
      (eq(objValue, objectProto[key]) && !hasOwnProperty.call(object, key))) {
    return srcValue;
  }
  return objValue;
}

/**
 * The base implementation of `_.property` without support for deep paths.
 *
 * @private
 * @param {string} key The key of the property to get.
 * @returns {Function} Returns the new function.
 */
function baseProperty(key) {
  return function(object) {
    return object == null ? undefined : object[key];
  };
}

/**
 * Gets the "length" property value of `object`.
 *
 * **Note:** This function is used to avoid a [JIT bug](https://bugs.webkit.org/show_bug.cgi?id=142792)
 * that affects Safari on at least iOS 8.1-8.3 ARM64.
 *
 * @private
 * @param {Object} object The object to query.
 * @returns {*} Returns the "length" value.
 */
var getLength = baseProperty('length');

/**
 * Checks if the given arguments are from an iteratee call.
 *
 * @private
 * @param {*} value The potential iteratee value argument.
 * @param {*} index The potential iteratee index or key argument.
 * @param {*} object The potential iteratee object argument.
 * @returns {boolean} Returns `true` if the arguments are from an iteratee call, else `false`.
 */
function isIterateeCall(value, index, object) {
  if (!isObject(object)) {
    return false;
  }
  var type = typeof index;
  if (type == 'number'
      ? (isArrayLike(object) && isIndex(index, object.length))
      : (type == 'string' && index in object)) {
    return eq(object[index], value);
  }
  return false;
}

/**
 * Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
 * comparison between two values to determine if they are equivalent.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to compare.
 * @param {*} other The other value to compare.
 * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
 * @example
 *
 * var object = { 'user': 'fred' };
 * var other = { 'user': 'fred' };
 *
 * _.eq(object, object);
 * // => true
 *
 * _.eq(object, other);
 * // => false
 *
 * _.eq('a', 'a');
 * // => true
 *
 * _.eq('a', Object('a'));
 * // => false
 *
 * _.eq(NaN, NaN);
 * // => true
 */
function eq(value, other) {
  return value === other || (value !== value && other !== other);
}

/**
 * Checks if `value` is array-like. A value is considered array-like if it's
 * not a function and has a `value.length` that's an integer greater than or
 * equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
 *
 * @static
 * @memberOf _
 * @type Function
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is array-like, else `false`.
 * @example
 *
 * _.isArrayLike([1, 2, 3]);
 * // => true
 *
 * _.isArrayLike(document.body.children);
 * // => true
 *
 * _.isArrayLike('abc');
 * // => true
 *
 * _.isArrayLike(_.noop);
 * // => false
 */
function isArrayLike(value) {
  return value != null &&
    !(typeof value == 'function' && isFunction(value)) && isLength(getLength(value));
}

/**
 * Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`,
 * `SyntaxError`, `TypeError`, or `URIError` object.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is an error object, else `false`.
 * @example
 *
 * _.isError(new Error);
 * // => true
 *
 * _.isError(Error);
 * // => false
 */
function isError(value) {
  return isObjectLike(value) &&
    typeof value.message == 'string' && objectToString.call(value) == errorTag;
}

/**
 * Checks if `value` is classified as a `Function` object.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`.
 * @example
 *
 * _.isFunction(_);
 * // => true
 *
 * _.isFunction(/abc/);
 * // => false
 */
function isFunction(value) {
  // The use of `Object#toString` avoids issues with the `typeof` operator
  // in Safari 8 which returns 'object' for typed array constructors, and
  // PhantomJS 1.9 which returns 'function' for `NodeList` instances.
  var tag = isObject(value) ? objectToString.call(value) : '';
  return tag == funcTag || tag == genTag;
}

/**
 * Checks if `value` is a valid array-like length.
 *
 * **Note:** This function is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/6.0/#sec-tolength).
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is a valid length, else `false`.
 * @example
 *
 * _.isLength(3);
 * // => true
 *
 * _.isLength(Number.MIN_VALUE);
 * // => false
 *
 * _.isLength(Infinity);
 * // => false
 *
 * _.isLength('3');
 * // => false
 */
function isLength(value) {
  return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER;
}

/**
 * Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`.
 * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is an object, else `false`.
 * @example
 *
 * _.isObject({});
 * // => true
 *
 * _.isObject([1, 2, 3]);
 * // => true
 *
 * _.isObject(_.noop);
 * // => true
 *
 * _.isObject(null);
 * // => false
 */
function isObject(value) {
  var type = typeof value;
  return !!value && (type == 'object' || type == 'function');
}

/**
 * Checks if `value` is object-like. A value is object-like if it's not `null`
 * and has a `typeof` result of "object".
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is object-like, else `false`.
 * @example
 *
 * _.isObjectLike({});
 * // => true
 *
 * _.isObjectLike([1, 2, 3]);
 * // => true
 *
 * _.isObjectLike(_.noop);
 * // => false
 *
 * _.isObjectLike(null);
 * // => false
 */
function isObjectLike(value) {
  return !!value && typeof value == 'object';
}

/**
 * Creates a compiled template function that can interpolate data properties
 * in "interpolate" delimiters, HTML-escape interpolated data properties in
 * "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data
 * properties may be accessed as free variables in the template. If a setting
 * object is given it takes precedence over `_.templateSettings` values.
 *
 * **Note:** In the development build `_.template` utilizes
 * [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl)
 * for easier debugging.
 *
 * For more information on precompiling templates see
 * [lodash's custom builds documentation](https://lodash.com/custom-builds).
 *
 * For more information on Chrome extension sandboxes see
 * [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval).
 *
 * @static
 * @memberOf _
 * @category String
 * @param {string} [string=''] The template string.
 * @param {Object} [options] The options object.
 * @param {RegExp} [options.escape] The HTML "escape" delimiter.
 * @param {RegExp} [options.evaluate] The "evaluate" delimiter.
 * @param {Object} [options.imports] An object to import into the template as free variables.
 * @param {RegExp} [options.interpolate] The "interpolate" delimiter.
 * @param {string} [options.sourceURL] The sourceURL of the template's compiled source.
 * @param {string} [options.variable] The data object variable name.
 * @param- {Object} [guard] Enables use as an iteratee for functions like `_.map`.
 * @returns {Function} Returns the compiled template function.
 * @example
 *
 * // Use the "interpolate" delimiter to create a compiled template.
 * var compiled = _.template('hello <%= user %>!');
 * compiled({ 'user': 'fred' });
 * // => 'hello fred!'
 *
 * // Use the HTML "escape" delimiter to escape data property values.
 * var compiled = _.template('<b><%- value %></b>');
 * compiled({ 'value': '<script>' });
 * // => '<b>&lt;script&gt;</b>'
 *
 * // Use the "evaluate" delimiter to execute JavaScript and generate HTML.
 * var compiled = _.template('<% _.forEach(users, function(user) { %><li><%- user %></li><% }); %>');
 * compiled({ 'users': ['fred', 'barney'] });
 * // => '<li>fred</li><li>barney</li>'
 *
 * // Use the internal `print` function in "evaluate" delimiters.
 * var compiled = _.template('<% print("hello " + user); %>!');
 * compiled({ 'user': 'barney' });
 * // => 'hello barney!'
 *
 * // Use the ES delimiter as an alternative to the default "interpolate" delimiter.
 * var compiled = _.template('hello ${ user }!');
 * compiled({ 'user': 'pebbles' });
 * // => 'hello pebbles!'
 *
 * // Use custom template delimiters.
 * _.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
 * var compiled = _.template('hello {{ user }}!');
 * compiled({ 'user': 'mustache' });
 * // => 'hello mustache!'
 *
 * // Use backslashes to treat delimiters as plain text.
 * var compiled = _.template('<%= "\\<%- value %\\>" %>');
 * compiled({ 'value': 'ignored' });
 * // => '<%- value %>'
 *
 * // Use the `imports` option to import `jQuery` as `jq`.
 * var text = '<% jq.each(users, function(user) { %><li><%- user %></li><% }); %>';
 * var compiled = _.template(text, { 'imports': { 'jq': jQuery } });
 * compiled({ 'users': ['fred', 'barney'] });
 * // => '<li>fred</li><li>barney</li>'
 *
 * // Use the `sourceURL` option to specify a custom sourceURL for the template.
 * var compiled = _.template('hello <%= user %>!', { 'sourceURL': '/basic/greeting.jst' });
 * compiled(data);
 * // => find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector
 *
 * // Use the `variable` option to ensure a with-statement isn't used in the compiled template.
 * var compiled = _.template('hi <%= data.user %>!', { 'variable': 'data' });
 * compiled.source;
 * // => function(data) {
 * //   var __t, __p = '';
 * //   __p += 'hi ' + ((__t = ( data.user )) == null ? '' : __t) + '!';
 * //   return __p;
 * // }
 *
 * // Use the `source` property to inline compiled templates for meaningful
 * // line numbers in error messages and stack traces.
 * fs.writeFileSync(path.join(cwd, 'jst.js'), '\
 *   var JST = {\
 *     "main": ' + _.template(mainText).source + '\
 *   };\
 * ');
 */
function template(string, options, guard) {
  // Based on John Resig's `tmpl` implementation (http://ejohn.org/blog/javascript-micro-templating/)
  // and Laura Doktorova's doT.js (https://github.com/olado/doT).
  var settings = templateSettings.imports._.templateSettings || templateSettings;

  if (guard && isIterateeCall(string, options, guard)) {
    options = undefined;
  }
  string = toString(string);
  options = assignInWith({}, options, settings, assignInDefaults);

  var imports = assignInWith({}, options.imports, settings.imports, assignInDefaults),
      importsKeys = keys(imports),
      importsValues = baseValues(imports, importsKeys);

  var isEscaping,
      isEvaluating,
      index = 0,
      interpolate = options.interpolate || reNoMatch,
      source = "__p += '";

  // Compile the regexp to match each delimiter.
  var reDelimiters = RegExp(
    (options.escape || reNoMatch).source + '|' +
    interpolate.source + '|' +
    (interpolate === reInterpolate ? reEsTemplate : reNoMatch).source + '|' +
    (options.evaluate || reNoMatch).source + '|$'
  , 'g');

  // Use a sourceURL for easier debugging.
  var sourceURL = 'sourceURL' in options ? '//# sourceURL=' + options.sourceURL + '\n' : '';

  string.replace(reDelimiters, function(match, escapeValue, interpolateValue, esTemplateValue, evaluateValue, offset) {
    interpolateValue || (interpolateValue = esTemplateValue);

    // Escape characters that can't be included in string literals.
    source += string.slice(index, offset).replace(reUnescapedString, escapeStringChar);

    // Replace delimiters with snippets.
    if (escapeValue) {
      isEscaping = true;
      source += "' +\n__e(" + escapeValue + ") +\n'";
    }
    if (evaluateValue) {
      isEvaluating = true;
      source += "';\n" + evaluateValue + ";\n__p += '";
    }
    if (interpolateValue) {
      source += "' +\n((__t = (" + interpolateValue + ")) == null ? '' : __t) +\n'";
    }
    index = offset + match.length;

    // The JS engine embedded in Adobe products needs `match` returned in
    // order to produce the correct `offset` value.
    return match;
  });

  source += "';\n";

  // If `variable` is not specified wrap a with-statement around the generated
  // code to add the data object to the top of the scope chain.
  var variable = options.variable;
  if (!variable) {
    source = 'with (obj) {\n' + source + '\n}\n';
  }
  // Cleanup code by stripping empty strings.
  source = (isEvaluating ? source.replace(reEmptyStringLeading, '') : source)
    .replace(reEmptyStringMiddle, '$1')
    .replace(reEmptyStringTrailing, '$1;');

  // Frame code as the function body.
  source = 'function(' + (variable || 'obj') + ') {\n' +
    (variable
      ? ''
      : 'obj || (obj = {});\n'
    ) +
    "var __t, __p = ''" +
    (isEscaping
       ? ', __e = _.escape'
       : ''
    ) +
    (isEvaluating
      ? ', __j = Array.prototype.join;\n' +
        "function print() { __p += __j.call(arguments, '') }\n"
      : ';\n'
    ) +
    source +
    'return __p\n}';

  var result = attempt(function() {
    return Function(importsKeys, sourceURL + 'return ' + source).apply(undefined, importsValues);
  });

  // Provide the compiled function's source by its `toString` method or
  // the `source` property as a convenience for inlining compiled templates.
  result.source = source;
  if (isError(result)) {
    throw result;
  }
  return result;
}

/**
 * Attempts to invoke `func`, returning either the result or the caught error
 * object. Any additional arguments are provided to `func` when it's invoked.
 *
 * @static
 * @memberOf _
 * @category Util
 * @param {Function} func The function to attempt.
 * @returns {*} Returns the `func` result or error object.
 * @example
 *
 * // Avoid throwing errors for invalid selectors.
 * var elements = _.attempt(function(selector) {
 *   return document.querySelectorAll(selector);
 * }, '>_>');
 *
 * if (_.isError(elements)) {
 *   elements = [];
 * }
 */
var attempt = rest(function(func, args) {
  try {
    return apply(func, undefined, args);
  } catch (e) {
    return isObject(e) ? e : new Error(e);
  }
});

module.exports = template;