Question

Is there any ways to short-up such chain call?

if (obj && obj.prop && obj.prop.subProp1 && obj.prop.subProp1.subPropFunc) {
    obj.prop.subProp1.subPropFunc();
}

The only alternative I can imagine is try-catch. Any other ideas?
*I really tired of writing these. It’s much easier in coffeescript using ?..

Answer 1

This should work given your sample code (haven’t tested “all cases”, just a copy of your sample):

function propsExist(obj) {
    if (!obj) return false;
    for (var i = 1; i < arguments.length; i++) {
        if (!obj[arguments[i]]) return false;
        obj = obj[arguments[i]];
    }
    return true;
}

if (propsExist(obj, "prop", "subProp1", "subPropFunc")) {
    obj.prop.subProp1.subPropFunc();
}

The method propsExist() takes a variable number of arguments, the first of which being the original object you want to check properties/functions on. It will iterate through the list of properties you send to it and check them in-order. If one doesn’t exist, it will return false. If it makes it through the whole loop, it validated successfully!

If you always want to call the sub-property’s function if it validates, you could also just change the propsExist function to call it instead of returning true (then rename the function to something like callIfValid(obj, ...)