setLimitedTimeout

plugin.js

(function() {
    if (typeof window.setLimitedTimeout === 'undefined' && typeof window.clearLimitedTimeout === 'undefined') { 
        var timers={},_id=0;
        window.setLimitedTimeout = function(test, reps, interval, cb) {
            var attempt = 0;
            var intFunc = typeof interval === 'function'
                ? interval
                : function(attempt) { return interval; };
            var id = _id++;
            timers[id] = setTimeout(function doit() {
                delete timers[id];
                if (attempt >= reps) {
                    cb && cb(false, attempt);
                }
                else if (test(++attempt) === true) {
                    cb && cb(true, attempt);
                }
                else {
                    timers[id] = setTimeout(doit, intFunc(attempt));
                }
            }, intFunc(attempt));
            return id;
        };
        window.clearLimitedTimeout = function(id) {
            clearTimeout(timers[id]);
            delete timers[id];
        };
    }
})();

// mininal version (no callback, no attempt # passed to functions, no interval function support)
/*var setLimitedTimeout = function(test, reps, interval) {
    setTimeout(function doit() {
        if (reps-- > 0 && test() === false) {
            setTimeout(doit, interval);
        }
    }, interval);
}*/

tests.js

// Example: making sure SP _spBodyOnLoadWrapper() has a chance to be called naturally, else call ourselves after 10 seconds
setLimitedTimeout(
    function() { return !!_spBodyOnLoadCalled; },
    100,
    100,
    function(success) {
    	success || _spBodyOnLoadWrapper();
    	console.log("SP ready to go");
    }
)
// Example: simply repeat 10 times with 100ms delay (similar to http://stackoverflow.com/a/10250983) 
setLimitedTimeout(
    function(i) { console.log("itr", i); },
    10,
    100
)
// Example: interval as a function, "backing-off" over time
setLimitedTimeout(
    function(i) { console.log("itr", i); },
    25,
    function(i) { return i * 50; }
)

window.foo = true;
setLimitedTimeout(
    function(itr) {
        window.foo = false;
        throw "Shouldn't see this";
        return true;
    },
    0,
    100,
    function(earlyExit, finalAttempt) {
        console.log(earlyExit === false && finalAttempt === 0 && window.foo === true ? "PASS" : "FAIL", "no-op", earlyExit, finalAttempt)
    }
)
setLimitedTimeout(
    function(itr) { return true; },
    10,
    100,
    function(earlyExit, finalAttempt) {
        console.log(earlyExit === true && finalAttempt === 1 ? "PASS" : "FAIL", "early exit", earlyExit, finalAttempt)
    }
)
setLimitedTimeout(
    function(itr) { return false; },
    10,
    100,
    function(earlyExit, finalAttempt) {
        console.log(earlyExit === false && finalAttempt === 10 ? "PASS" : "FAIL", "exceed reps", earlyExit, finalAttempt)
    }
)
setLimitedTimeout(
    function(itr) { return itr === 10; },
    10,
    100,
    function(earlyExit, finalAttempt) {
        console.log(earlyExit === true && finalAttempt === 10 ? "PASS" : "FAIL", "on last", earlyExit, finalAttempt)
    }
)
setLimitedTimeout(
    function(itr) { return itr === 10; },
    10,
    100,
    function(earlyExit, finalAttempt) {
        console.log(earlyExit === true && finalAttempt === 10 ? "PASS" : "FAIL", "on last", earlyExit, finalAttempt)
    }
)