尝试使Javascript函数同步运行

Question

I'm having trouble with the following code snippet. My init method needs to run and complete the getLocation() function before the initializeMapp() and geoListen() can run. I have rsvp.js linked as a resource, but not quite sure how to implement. I also tried the jQuery $when.done method. Any help is appreciated.

jQuery Method:

//initial page load method
function init() {

    //get user location then builds map and listens to database
    $.when(getLocation()).done.(function () {

       //build map now that you have user location
        initializeMap();

       //Starts listening to database changes
       geoListen();

    })

}

RSVP method:

 //initial page load method
 function init() {

      //get user location then builds map and listens to database
     getLocation().then(function () {

     //build map now that you have user location
     initializeMap();

     //Starts listening to database changes
     geoListen();

  })

 }   

Answer 1

you can make your getLocation function accept callbacks and execute them when getLocation finishes

getLocation = function(cb1, cb2) {
  // when done 
  cb1()
  cb2()
}

function init() {
  getLocation(initializeMap, geoListen)
}

or you can pass an array of callback references and loop through them in getLocation and call them

alternatively you can use Q.js and return a promise from getLocation