blob: 29e1939902313097b65cd6aa8e6d3ef9aae1f740 [file] [log] [blame]
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;