In the following code snippet,
var paintMode = data.hasOwnProperty('regions') ?
'regions' : data.hasOwnProperty('vpcs') ?
'vpcs' : data.hasOwnProperty('zones') ?
'zones' : data.hasOwnProperty('subnets') ?
'subnets' : data.hasOwnProperty('clusters') ? 'clusters' : null;
I've used a deeply nested (condition) ? true : false
(condition) ? true : false
-- is this acceptable? is it optimized? If its bad is there an alternative?
It is used inside a recursive function which does a few SVG operations, here's the function snippet if you are curious.
function paintGroups(data) {
var paintMode = data.hasOwnProperty('regions') ? 'regions' : data.hasOwnProperty('vpcs') ? 'vpcs' : data.hasOwnProperty('zones') ? 'zones' : data.hasOwnProperty('subnets') ? 'subnets' : data.hasOwnProperty('clusters') ? 'clusters' : null,
depth = data[paintMode].length,
i,
Shape; //= raphealObj.rect();
// Register stacking order
// Paint a shape with styles based on paintMode
// Store its id & Label for other ops.
if(paintMode) {
for(i = 0; i < depth; i++) {
paintGroups(data[paintMode][i]);
}
}
// to reverse the order of paint - place your statements here
}
Generally speaking using binary operations should be faster than conditional statements with branching because of branch prediction, caching, yada yada yada. But your code is fine. I like the && || but it's just a preference and not based on anything empirical.
var data = {a: 1, b: 2, c: 3};
var result = data.x ||
data.y && "y" ||
data.z && "z" ||
data.w && "w" ||
null;
I didn't feel like typing .hasOwnProperty.
EDIT After actually looking at your code
var paintMode = data.regions || data.vpcs || data.zones || data.subnets || data.clusters || null;
if(paintNode) {
for(var i=0; i<paintMode.length; i++)
paintGroups(paintMode[i]);
}
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