Tasks

Like native JavaScript promises, this library is designed to work with a large number of chained asynchronous requests involved with business rules and data return in a simple way.

Assim como os promises nativos de JavaScript, esta biblioteca foi desenhada para trabalhar com uma grande quantidade de requisições assíncronas encadeadas envolvendo regras de negócio e retorno de dados de uma forma simples.

var tarefas = new Tasks.Task(function(yes, no){
     setTimeout(function(){
     	yes('love potatoes');
     }, 1000);
}).then(function(yes, no, anything){
     console.info(anything);
     setTimeout(function(){
     	yes(anything + ' and bacon');
     }, 1000);
}).then(function(yes, no, anything){
     console.info(anything);
     setTimeout(function(){
     	throw "error message";
     }, 1000);
});

//  see that the next task will be bind to the first one generated,
//  but this will not change the execution order, internally this
//  new task will be created as the last task son
tarefas.then(function(yes, no, anything){

     // this one never will be executed because the last task is
     // lauching an exception so, the catch will be activated 
     console.info(anything);
     setTimeout(function(){
     	yes(anything + ' and onion rings');
     }, 1000);
}).catch(function(err){
     console.error(err.message);
});

Add new tasks in the end using the original task or some one other in the middle will help you join multiples requests and return something like a promise with data access to the programmer continue working with tasks, like this:

var dao = {
    getProduct: (data) => {
        return new Tasks.Task((next, stop) => {

            $.ajax({
                url:    "product/infos"

                data:   data,

                method: 'GET',

                success(infos){
                    next({ 
                        type:         infos.type,
                        name:         infos.name,
                        description:  infos.description
                    });
                },

                failure(err){
                    stop(err);
                }
            });

        }).then(function(next, stop, dataFromOtherRequest){

            $.ajax({
                url:    "product/images"
                
                data:   { type: dataFromOtherRequest.type },

                method: 'GET',

                success(prices){
                    dataFromOtherRequest.prices = prices;
                    next(dataFromOtherRequest);
                },

                failure(err){
                    stop(err);
                }
            });

        }).then(function(next, stop, dataFromOtherRequest){

            $.ajax({
                url:    "product/images"
                
                data:   data,

                method: 'GET',

                success(images){
                    dataFromOtherRequest.images = images;
                    next(dataFromOtherRequest);
                },

                failure(err){
                    stop(err)
                }
            });

        });
    }
};

dao.getProduct({ code: 1000 }).then((go, dontgo, data) => {

    // display data in screen or anothor stuff

}).catch(e => {
    alert(e.message);
});