| var baseToString = require('../internal/baseToString'), |
| isIterateeCall = require('../internal/isIterateeCall'), |
| isObject = require('../lang/isObject'), |
| isRegExp = require('../lang/isRegExp'); |
| |
| /** Used as default options for `_.trunc`. */ |
| var DEFAULT_TRUNC_LENGTH = 30, |
| DEFAULT_TRUNC_OMISSION = '...'; |
| |
| /** Used to match `RegExp` flags from their coerced string values. */ |
| var reFlags = /\w*$/; |
| |
| /** |
| * Truncates `string` if it's longer than the given maximum string length. |
| * The last characters of the truncated string are replaced with the omission |
| * string which defaults to "...". |
| * |
| * @static |
| * @memberOf _ |
| * @category String |
| * @param {string} [string=''] The string to truncate. |
| * @param {Object|number} [options] The options object or maximum string length. |
| * @param {number} [options.length=30] The maximum string length. |
| * @param {string} [options.omission='...'] The string to indicate text is omitted. |
| * @param {RegExp|string} [options.separator] The separator pattern to truncate to. |
| * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. |
| * @returns {string} Returns the truncated string. |
| * @example |
| * |
| * _.trunc('hi-diddly-ho there, neighborino'); |
| * // => 'hi-diddly-ho there, neighbo...' |
| * |
| * _.trunc('hi-diddly-ho there, neighborino', 24); |
| * // => 'hi-diddly-ho there, n...' |
| * |
| * _.trunc('hi-diddly-ho there, neighborino', { |
| * 'length': 24, |
| * 'separator': ' ' |
| * }); |
| * // => 'hi-diddly-ho there,...' |
| * |
| * _.trunc('hi-diddly-ho there, neighborino', { |
| * 'length': 24, |
| * 'separator': /,? +/ |
| * }); |
| * // => 'hi-diddly-ho there...' |
| * |
| * _.trunc('hi-diddly-ho there, neighborino', { |
| * 'omission': ' [...]' |
| * }); |
| * // => 'hi-diddly-ho there, neig [...]' |
| */ |
| function trunc(string, options, guard) { |
| if (guard && isIterateeCall(string, options, guard)) { |
| options = undefined; |
| } |
| var length = DEFAULT_TRUNC_LENGTH, |
| omission = DEFAULT_TRUNC_OMISSION; |
| |
| if (options != null) { |
| if (isObject(options)) { |
| var separator = 'separator' in options ? options.separator : separator; |
| length = 'length' in options ? (+options.length || 0) : length; |
| omission = 'omission' in options ? baseToString(options.omission) : omission; |
| } else { |
| length = +options || 0; |
| } |
| } |
| string = baseToString(string); |
| if (length >= string.length) { |
| return string; |
| } |
| var end = length - omission.length; |
| if (end < 1) { |
| return omission; |
| } |
| var result = string.slice(0, end); |
| if (separator == null) { |
| return result + omission; |
| } |
| if (isRegExp(separator)) { |
| if (string.slice(end).search(separator)) { |
| var match, |
| newEnd, |
| substring = string.slice(0, end); |
| |
| if (!separator.global) { |
| separator = RegExp(separator.source, (reFlags.exec(separator) || '') + 'g'); |
| } |
| separator.lastIndex = 0; |
| while ((match = separator.exec(substring))) { |
| newEnd = match.index; |
| } |
| result = result.slice(0, newEnd == null ? end : newEnd); |
| } |
| } else if (string.indexOf(separator, end) != end) { |
| var index = result.lastIndexOf(separator); |
| if (index > -1) { |
| result = result.slice(0, index); |
| } |
| } |
| return result + omission; |
| } |
| |
| module.exports = trunc; |