2 Copyright (c) 2010, Yahoo! Inc. All rights reserved.
3 Code licensed under the BSD License:
4 http://developer.yahoo.com/yui/license.html
8 YUI.add('substitute', function(Y) {
11 * String variable substitution and string formatting.
12 * If included, the substitute method is added to the YUI instance.
17 var L = Y.Lang, DUMP = 'dump', SPACE = ' ', LBRACE = '{', RBRACE = '}',
20 * The following methods are added to the YUI instance
21 * @class YUI~substitute
25 * Does variable substitution on a string. It scans through the string
26 * looking for expressions enclosed in { } braces. If an expression
27 * is found, it is used a key on the object. If there is a space in
28 * the key, the first word is used for the key and the rest is provided
29 * to an optional function to be used to programatically determine the
30 * value (the extra information might be used for this decision). If
31 * the value for the key in the object, or what is returned from the
32 * function has a string value, number value, or object value, it is
33 * substituted for the bracket expression and it repeats. If this
34 * value is an object, it uses the Object's toString() if this has
35 * been overridden, otherwise it does a shallow dump of the key/value
36 * pairs if Y.dump is available (if dump isn't available, toString()
39 * This method is included in the 'substitute' module. It is not included
43 * @param {string} s The string that will be modified.
44 * @param {object} o An object containing the replacement values.
45 * @param {function} f An optional function that can be used to
46 * process each match. It receives the key,
47 * value, and any extra metadata included with
48 * the key inside of the braces.
49 * @param {boolean} recurse if true, the replacement will be recursive,
50 * letting you have replacement tokens in replacement text. The
52 * @return {string} the substituted string.
55 substitute = function(s, o, f, recurse) {
56 var i, j, k, key, v, meta, saved = [], token, dump,
60 i = s.lastIndexOf(LBRACE, lidx);
64 j = s.indexOf(RBRACE, i);
69 //Extract key and meta info
70 token = s.substring(i + 1, j);
73 k = key.indexOf(SPACE);
75 meta = key.substring(k + 1);
76 key = key.substring(0, k);
82 // if a substitution function was provided, execute it
92 v = Y.dump(v, parseInt(meta, 10));
96 // look for the keyword 'dump', if found force obj dump
97 dump = meta.indexOf(DUMP);
99 meta = meta.substring(4);
102 // use the toString if it is not the Object toString
103 // and the 'dump' meta info was not found
104 if (v.toString === Object.prototype.toString ||
106 v = Y.dump(v, parseInt(meta, 10));
112 } else if (!L.isString(v) && !L.isNumber(v)) {
113 // This {block} has no replace string. Save it for later.
114 v = '~-' + saved.length + '-~';
115 saved[saved.length] = token;
120 s = s.substring(0, i) + v + s.substring(j + 1);
128 // restore saved {block}s
129 for (i = saved.length - 1; i >= 0; i = i - 1) {
130 s = s.replace(new RegExp('~-' + i + '-~'), LBRACE +
131 saved[i] + RBRACE, 'g');
138 Y.substitute = substitute;
139 L.substitute = substitute;
143 }, '3.3.0' ,{optional:['dump']});