Angularjs $watchCollection发生了什么变化?
使用Angularjs $watchCollection发生了什么变化?,angularjs,Angularjs,使用$watchCollection检测已更改的密钥 newValue: Object {contentType: "217", audioType: 1, wordType: 209} oldValue: Object {contentType: "217", audioType: 1, wordType: 210} 通常一次只能更改一个键。我想检测哪一个,这样我就可以将更改保存到cookies中,而不必保存所有更改,即使它没有更改 谢谢 在您的情况下,您可以创建过滤器,以发现差异: a
$watchCollection
检测已更改的密钥
newValue: Object {contentType: "217", audioType: 1, wordType: 209}
oldValue: Object {contentType: "217", audioType: 1, wordType: 210}
通常一次只能更改一个键。我想检测哪一个,这样我就可以将更改保存到cookies中,而不必保存所有更改,即使它没有更改
谢谢 在您的情况下,您可以创建
过滤器
,以发现差异:
app.filter('diff', function () {
return function (objectA, objectB) {
var propertyChanges = [];
var objectGraphPath = ["this"];
(function(a, b) {
if(a.constructor == Array) {
// BIG assumptions here: That both arrays are same length, that
// the members of those arrays are _essentially_ the same, and
// that those array members are in the same order...
for(var i = 0; i < a.length; i++) {
objectGraphPath.push("[" + i.toString() + "]");
arguments.callee(a[i], b[i]);
objectGraphPath.pop();
}
} else if(a.constructor == Object || (a.constructor != Number &&
a.constructor != String && a.constructor != Date &&
a.constructor != RegExp && a.constructor != Function &&
a.constructor != Boolean)) {
// we can safely assume that the objects have the
// same property lists, else why compare them?
for(var property in a) {
objectGraphPath.push(("." + property));
if(a[property].constructor != Function) {
arguments.callee(a[property], b[property]);
}
objectGraphPath.pop();
}
} else if(a.constructor != Function) { // filter out functions
if(a != b) {
propertyChanges.push({ "Property": objectGraphPath.join(""), "ObjectA": a, "ObjectB": b });
}
}
})(objectA, objectB);
return propertyChanges;
}
});
积分到此处不需要
$watchCollection
只需使用$watch
,第三个参数为true
var diff = $filter('diff')(newValue, oldValue);