How to terminate forEachObject loop?

Question

This question belongs to fabricJS and canvas. In following case check is there any object which property true (obj.background == true). There can be several images on canvas. After the first object detection, I want to terminate the loop. How I do this? I ave used return false; but does not work. Here is the function.

    canvas.forEachObject(function(obj){
        if(obj.isType('image') && obj.hasOwnProperty('background')){
            if(!obj.background == true){
                alert("true");
                return false;
            } 
        }
    });  

Answer 1

Now i haven't used FabricJS (awaiting a spam of down-votes already) looking at the source there is a getObjects() method. What this does is return an array of objects instead of a custom iterator like forEachObject().

So with that you could use all the normal array itteration methods like forEach(), some(), every() etc which will allow you to do what you wish.

So my understanding is you want to check if the object is an image and if its background property is true, and abort the loop on the first occurrence? This should do it.

canvas
    .getObjects()
    .some(obj => {
        if (obj.isType('image') && obj.hasOwnProperty('background') && obj.background === true) {
            console.log('Aww shucks, you found me.');
            return true;
        }
    });

Obviously this is pseudo code. Essentially it will loop all objects and abort if your return true. If any element does return true the return value from some will also be true.

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EDIT after Michał Dopieralski comment.

I overlooked the fact getObjects can be passed a type and will filter the results for you. So using that things get even simpler.

canvas
    .getObjects('image')
    .some(obj => {
        if (obj.background === true) {
            console.log('Aww shucks, you found me.');
            return true;
        }
    });

array some docs

fabricjs getObjects source

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EDIT: On a side note the hasOwnProperty check shouldn't be required i don't think. So long as obj is defined then accessing a property of it that doesn't exist will return undefined. Which will fail the === true check.