dojo 官方翻译 dojo/Deferred

延迟，异步调用

官网地址：http://dojotoolkit.org/reference-guide/1.9/dojo/Deferred.html

 

require(["dojo/Deferred", "dojo/dom", "dojo/on", "dojo/domReady!"],

function(Deferred, dom, on){

  function asyncProcess(){

    var deferred = new Deferred();



    dom.byId("output").innerHTML = "I'm running...";



    setTimeout(function(){

      deferred.resolve("success");

    }, 1000);



    return deferred.promise;

  }



  on(dom.byId("startButton"), "click", function(){

    var process = asyncProcess();

    process.then(function(results){

      dom.byId("output").innerHTML = "I'm finished, and the result was: " + results;

    });

  });



});

链式调用

require(["dojo/Deferred", "dojo/dom", "dojo/on", "dojo/domReady!"],

function(Deferred, dom, on){

  function asyncProcess(msg){

    var deferred = new Deferred();



    dom.byId("output").innerHTML += "<br/>I'm running...";



    setTimeout(function(){

      deferred.resolve(msg);

    }, 1000);



    return deferred.promise;

  }



  on(dom.byId("startButton"), "click", function(){

    var process = asyncProcess("first");

    process.then(function(results){

      dom.byId("output").innerHTML += "<br/>I'm finished, and the result was: " + results;

      return asyncProcess("second");

    }).then(function(results){

      dom.byId("output").innerHTML += "<br/>I'm really finished now, and the result was: " + results;

    });

  });



});

reject

require(["dojo/Deferred", "dojo/dom", "dojo/on", "dojo/domReady!"],

function(Deferred, dom, on){

  function asyncProcess(msg){

    var deferred = new Deferred();



    dom.byId("output").innerHTML += "<br/>I'm running...";



    setTimeout(function(){

      deferred.progress("halfway");

    }, 1000);



    setTimeout(function(){

      deferred.resolve("finished");

    }, 2000);



    setTimeout(function(){

      deferred.reject("ooops");

    }, 1500);



    return deferred.promise;

  }



  on(dom.byId("startButton"), "click", function(){

    var process = asyncProcess();

    process.then(function(results){

      dom.byId("output").innerHTML += "<br/>I'm finished, and the result was: " + results;

    }, function(err){

      dom.byId("output").innerHTML += "<br/>I errored out with: " + err;

    }, function(progress){

      dom.byId("output").innerHTML += "<br/>I made some progress: " + progress;

    });

  });

cancel

require(["dojo/Deferred", "dojo/dom", "dojo/on", "dojo/domReady!"],

function(Deferred, dom, on){

  function asyncProcess(){

    var timeout;

    var deferred = new Deferred(function(reason){

      clearTimeout(timeout);

      dom.byId("output").innerHTML += "<br/>I was cancelled with reason: " + reason;

    });



    dom.byId("output").innerHTML += "<br/>I'm running...";



    timeout = setTimeout(function(){

      dom.byId("output").innerHTML += "<br/>My process completed!";

      deferred.resolve("finished");

    }, 2000);



    return deferred.promise;

  }



  on(dom.byId("startButton"), "click", function(){

    var process = asyncProcess();

    process.then(function(results){

      dom.byId("output").innerHTML += "<br/>I'm finished, and the result was: " + results;

    });



    setTimeout(function(){

      process.cancel("goodbye");

    }, 1000);

  });



});