/*!
* CanJS - 1.1.5 (2013-03-27)
* http://canjs.us/
* Copyright (c) 2013 Bitovi
* Licensed MIT
*/
(function (can, window, undefined) {/*!
* CanJS - 1.1.5 (2013-03-27)
* http://canjs.us/
* Copyright (c) 2013 Bitovi
* Licensed MIT
*/
(function (can, window, undefined) {* - 'this' will be the deepest item changed - 'this' will be any changes within , but will be the this returned tells if the parts part of a delegate matches the broken up props of the event gives the prop to use as 'this' - parts - the attribute name of the delegate split in parts ['foo','*'] - props - the split props of the event that happened ['foo','bar','0'] - returns - the attribute to delegate too ('foo.bar'), or null if not a match
var delegateMatches = function (parts, props) {check props parts are the same or
var len = parts.length,
i = 0,keeps the matched props we will use
matchedProps = [],
prop;if the event matches
for (i; i < len; i++) {
prop = props[i]if no more props (but we should be matching them) return null
if (typeof prop !== 'string') {
return null;
} elseif we have a "**", match everything
if (parts[i] == "**") {
return props.join(".");
} elsea match, but we want to delegate to "*"
if (parts[i] == "*") {only do this if there is nothing after ...
matchedProps.push(prop);
}
else if (prop === parts[i]) {
matchedProps.push(prop);
} else {
return null;
}
}
return matchedProps.join(".");
},gets a change event and tries to figure out which delegates to call
delegateHandler = function (event, prop, how, newVal, oldVal) {pre-split properties to save some regexp time
var props = prop.split("."),
delegates = (this._observe_delegates || []).slice(0),
delegate, attr, matchedAttr, hasMatch, valuesEqual;
event.attr = prop;
event.lastAttr = props[props.length - 1];for each delegate
for (var i = 0; delegate = delegates[i++];) {if there is a batchNum, this means that this event is part of a series of events caused by a single attrs call. We don't want to issue the same event multiple times setting the batchNum happens later
if ((event.batchNum && delegate.batchNum === event.batchNum) || delegate.undelegated) {
continue;
}reset match and values tests
hasMatch = undefined;
valuesEqual = true;yeah, all this under here has to be redone v for each attr in a delegate
for (var a = 0; a < delegate.attrs.length; a++) {
attr = delegate.attrs[a];check if it is a match
if (matchedAttr = delegateMatches(attr.parts, props)) {
hasMatch = matchedAttr;
}if it has a value, make sure it's the right value if it's set, we should probably check that it has a value no matter what
if (attr.value && valuesEqual) {
valuesEqual = attr.value === "" + this.attr(attr.attr)
} else if (valuesEqual && delegate.attrs.length > 1) {if there are multiple attributes, each has to at least have some value
valuesEqual = this.attr(attr.attr) !== undefined
}
}if there is a match and valuesEqual ... call back
if (hasMatch && valuesEqual) {how to get to the changed property from the delegate
var from = prop.replace(hasMatch + ".", "");if this event is part of a batch, set it on the delegate to only send one event
if (event.batchNum) {
delegate.batchNum = event.batchNum
}if we listen to change, fire those with the same attrs TODO: the attrs should probably be using from
if (delegate.event === 'change') {
arguments[1] = from;
event.curAttr = hasMatch;
delegate.callback.apply(this.attr(hasMatch), can.makeArray(arguments));
} else if (delegate.event === how) {if it's a match, callback with the location of the match
delegate.callback.apply(this.attr(hasMatch), [event, newVal, oldVal, from]);
} else if (delegate.event === 'set' && how == 'add') {if we are listening to set, we should also listen to add
delegate.callback.apply(this.attr(hasMatch), [event, newVal, oldVal, from]);
}
}
}
};
can.extend(can.Observe.prototype, {
delegate: function (selector, event, handler) {
selector = can.trim(selector);
var delegates = this._observe_delegates || (this._observe_delegates = []),
attrs = [],
selectorRegex = /([^\s=,]+)(?:=("[^",]*"|'[^',]*'|[^\s"',]*))?(,?)\s*/g,
matches;parse each property in the selector
while (matches = selectorRegex.exec(selector)) {we need to do a little doctoring to make up for the quotes.
if (matches[2] && $.inArray(matches[2].substr(0, 1), ['"', "'"]) >= 0) {
matches[2] = matches[2].substr(1, -1);
}
attrs.push({the attribute name
attr: matches[1],the attribute name, pre-split for speed
parts: matches[1].split('.'),the value associated with this property (if there was one given)
value: matches[2],whether this selector combines with the one after it with AND or OR
or: matches[3] === ','
});
}delegates has pre-processed info about the event
delegates.push({the attrs name for unbinding
selector: selector,an object of attribute names and values {type: 'recipe',id: undefined} undefined means a value was not defined
attrs: attrs,
callback: handler,
event: event
});
if (delegates.length === 1) {
this.bind("change", delegateHandler)
}
return this;
},
undelegate: function (selector, event, handler) {
selector = can.trim(selector);
var i = 0,
delegates = this._observe_delegates || [],
delegateOb;
if (selector) {
while (i < delegates.length) {
delegateOb = delegates[i];
if (delegateOb.callback === handler || (!handler && delegateOb.selector === selector)) {
delegateOb.undelegated = true;
delegates.splice(i, 1)
} else {
i++;
}
}
} else {remove all delegates
delegates = [];
}
if (!delegates.length) {can.removeData(this, "_observe_delegates");
this.unbind("change", delegateHandler)
}
return this;
}
});add helpers for testing ..
can.Observe.prototype.delegate.matches = delegateMatches;
})(can, this);