There seem to be many answers to questions on how to use bluebird promises to call asynchronous functions from a for / while loop, but as far as I can see, all require node.js to work (eg promise.method() or process.nextTick() ; eg such as: While loop using bluebird promises ). Is there any way to do this in plain js + blue bird? Thanks for your time.
Well, once something is a promise returning function - you don't really care about the environment the library takes care of it for you:
Promise.delay(1000); // an example of an asynchronous function
See this question on converting functions to promise returning ones.
Now, once you have that sort of function a loop becomes pretty trivial:
function whileLoop(condition, fn){
return Promise.try(function loop(val){
return Promise.resolve(condition()).then(function(res){
if(!res) return val; // done
return fn().then(loop); // keep on looping
});
});
}
Which would let you do something like:
var i = 0;
whileLoop(function(){
return i < 10; // can also return a promise for async here
}, function body(){
console.log("In loop body");
i++;
return Promise.delay(1000);
}).then(function(){
console.log("All done!");
});
To demonstrate this works in a browser - here's a JSFiddle
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