Merging Objects in AS3
I want to merge two A3 Objects together which contain some of the same Keys but different values. I've found many posts regarding adding two Objects together but I want to merge the two objects together s开发者_Go百科o if the second object has different values they take priority. I have two Objects below:
_propsObj = new Object();
_propsObj.baseColour = 0x303237;
_propsObj.animation = false;
_propsObj.font = "Verdana";
_propsObj.fontColour = 0xffffff;
_propsObj.baseFontSize = 14;
_propsObj2 = new Object();
_propsObj2.animation = true;
_propsObj2.fontColour = 0xffffff;
_propsObj2.baseFontSize = 10;
My desired ouput Object would accept the new values of the second Object but maintain the values of the first Object :
_outputObj.baseColour = 0x303237;
_outputObj.animation = true;
_outputObj.font = "Verdana";
_outputObj.fontColour = 0xffffff;
_outputObj.baseFontSize = 10;
I wasn't sure if I should be using Arrray.concat do this or if there is an easier solution? Any help would be appreciated.
the merge method hereunder
var _propsObj:Object = new Object();
_propsObj.baseColour = 0x303237;
_propsObj.animation = false;
_propsObj.font = "Verdana";
_propsObj.fontColour = 0xffffff;
_propsObj.baseFontSize = 14;
var _propsObj2:Object = new Object();
_propsObj2.animation = true;
_propsObj2.fontColour = 0xffffff;
_propsObj2.baseFontSize = 10;
var merged:Object = merge( _propsObj, _propsObj2 );
private function merge( obj0:Object, obj1:Object ):Object
{
var obj:Object = { };
for( var p:String in obj0 )
{
obj[ p ] = ( obj1[ p ] != null ) ? obj1[ p ] : obj0[ p ];
trace( p, ' : obj0', obj0[ p ], 'obj1', obj1[ p ], '-> new value = ', obj[ p ] );
}
return obj;
}
traces:
font : obj0 Verdana obj1 undefined -> new value = Verdana
fontColour : obj0 16777215 obj1 16777215 -> new value = 16777215
baseColour : obj0 3158583 obj1 undefined -> new value = 3158583
animation : obj0 false obj1 true -> new value = true
baseFontSize : obj0 14 obj1 10 -> new value = 10
the important line is :
obj[ p ] = ( obj1[ p ] != null ) ? obj1[ p ] : obj0[ p ];
it recursively creates the property on the new Object 'obj' and checks if that property is assigned on the 2nd object, if so it assigns the value of the second object to that property, otherwise it falls back to the value of that property on the first object.
NB: if a value is not set on the first object, it will not be looked up in the second object.
You can use something like this:
private function merge(obj1:Object, obj2:Object):Object {
var result:Object = new Object();
for (var param:String in obj1) {
result[param] = (obj2[param] ? obj2[param] : obj1[param]);
}
return result;
}
Usage:
_outputObj = merge(_propsObj, _propsObj2);
If you want to overwrite the existing values in the first object, you could just do this:
for ( var p in _propsObj2 )
_propsObj[p] = _propsObj2[p];
var _propsObj:Object = new Object();
_propsObj.baseColour = 0x303237;
_propsObj.animation = false;
_propsObj.font = "Verdana";
_propsObj.fontColour = 0xffffff;
_propsObj.baseFontSize = 14;
var _propsObj2:Object = new Object();
_propsObj2.animation = true;
_propsObj2.fontColour = 0xffffff;
_propsObj2.baseFontSize = 10;
var mergedObj:Object = new Object();
//Adds the values from the first object
for (var r in _propsObj)
{
mergedObj[r] = _propsObj[r];
}
//Adds the values from the second object
for(var s in _propsObj2)
{
mergedObj[s] = _propsObj2[s];
}
//Checking the merged values
for(var t in mergedObj)
{
trace([t, mergedObj[t]]);
}
Well, here's a generic utility function that does it:
public static function zip(objects:Array):Object
{
var r:Object = {};
for each (var o:Object in objects)
for (var k:String in o)
r[k] = o[k];
return r;
}
Usage example:
var obj:Object = {
"foo": 1,
"bar": 2,
"baz": 3
};
var obj2:Object = {
"bar": 4,
"baz": 6
};
var obj3:Object = {
"foo": 3,
"bar": 6
};
var result:Object = zip([obj, obj2, obj3]);
for (var k:String in result)
trace("Property:", k, result[k]);
Output:
Property: foo 3
Property: baz 6
Property: bar 6
Side note: This is a "lossy" method in that the resultant object does not know where the individual properties came from and retains only the latest version of the value. If you want to preserve that information then there's another way to do this, using the prototype chain. It's how the Flex framework chains style settings, for example.
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