如何顺序调用ajax函数

Question

    function loadGraphInSeq(startDate,endDate,calcSubStart,calcSubEnd){
        var graphName=new Array();
        $('section div.graph_box').each(function(){
            if ($(this).css('display')=='block') {
                graphName.push($(this).attr('id'));
            }
        });
        for (index=0;index<graphName.length;index++) {
            switch (graphName[index]) {
                case 'allquery':
                    break;
                case 'alwazinc':
                    alwayzincreasing(calcSubStart,calcSubEnd,startDate,endDate);
                    break;
                case 'segment':
                    ajaxCallingSegment(startDate,endDate,calcSubStart,calcSubEnd);
                    break;
                case 'answeredresponse':
                   ajaxCallingSegmentRespDay(startDate,endDate,calcSubStart,calcSubEnd);
                    break;
                case 'segmentresponse':
                   ajaxCallingSegmentRespHours(startDate,endDate,calcSubStart,calcSubEnd);
                    break;
                case 'lessthanDonut':
                    ajaxCallinglessthanDonut(startDate,endDate,calcSubStart,calcSubEnd,'total');
                    ajaxCallinglessthanDonut(startDate,endDate,calcSubStart,calcSubEnd,'latency');
                    ajaxCallinglessthanDonut(startDate,endDate,calcSubStart,calcSubEnd,'delivery');
                    break;
                case 'carrierPie':
                    ajaxCallingCarrierPie(startDate,endDate,calcSubStart,calcSubEnd);
                    break;
            }

        }
    }

Let me explain a bit, I have class .graph_box which shows graphs. the order of those divs changes when I change the date loadGraphInSeq is called and I want to load the graph in sequence ie until and unless one graph is loaded other function should not be called. The function in switch statements call the function to load the graphs. Currently this function load all the function in one go. The graphName stacks all the graphs(who are not hidden) name that need to be loaded.

Answer 1

You can use the deferred object that $.get returns (or any other XHR method of jQuery).

Using your code I've updated the example. The asynch and synch functions should all return a promise. The asynch (XHR requests) will automatically resolve or fail the synch you do it manually (included in the example)

//your synchronous function
function alwayzincreasing(calcSubStart,calcSubEnd,startDate,endDate){
  var deferred = $.Deferred();  
  deferred.resolve("to be passed to the next function");
  //do stuff here (non asynch);
  //return a promise
  return deferred.promise();
};
function ajaxCallingSegment(startDate,endDate,calcSubStart,calcSubEnd){
  //make sure you return the return value of $.ajax or $.get or $.post
  return $.get("url");//do not put unsuccess or anthing like that here
}
function loadGraphInSeq(startDate,endDate,calcSubStart,calcSubEnd){
  var graphName=new Array(),fn=[],i=-1,len,p,d,e;
  $('section div.graph_box').each(function(){
    if ($(this).css('display')=='block') {
      graphName.push($(this).attr('id'));
    }
  });
  for (index=0;index<graphName.length;index++) {
    switch (graphName[index]) {
      case 'allquery':
        break;
      case 'alwazinc':
        fn.push(function(){
          return alwayzincreasing(calcSubStart,calcSubEnd,startDate,endDate);
        });
        break;
      case 'segment':
        fn.push(function(){
          return ajaxCallingSegment(startDate,endDate,calcSubStart,calcSubEnd);
        });
        break;
      case 'answeredresponse':
        fn.push(function(){
          return ajaxCallingSegmentRespDay(startDate,endDate,calcSubStart,calcSubEnd);
        });
        break;
      case 'segmentresponse':
        fn.push(function(){
          return ajaxCallingSegmentRespHours(startDate,endDate,calcSubStart,calcSubEnd);
        });
        break;
      case 'lessthanDonut':
        fn.push(function(){
          return ajaxCallinglessthanDonut(startDate,endDate,calcSubStart,calcSubEnd,'total');
        });
        fn.push(function(){
          return ajaxCallinglessthanDonut(startDate,endDate,calcSubStart,calcSubEnd,'latency');
        });
        fn.push(function(){
          return ajaxCallinglessthanDonut(startDate,endDate,calcSubStart,calcSubEnd,'delivery');
        });
        break;
      case 'carrierPie':
        fn.push(function(){
          return ajaxCallingCarrierPie(startDate,endDate,calcSubStart,calcSubEnd);
        });
        break;
    }
  }
  len = fn.length;
  d=jQuery.Deferred();
  p = d.promise();
  while(++i<len){
    p.then(fn[i]);
  }
  p.then(function(){
    console.log("done");
  },
  function(){
    console.log("Failed");
  });
  d.resolve();
}

Answer 2

This seems to be a very long way to achieve what I want,I have changed the function loadGraphInSeq to return only function name and I am calling that function loadGraphInSeq after every ajax function to get name of next function to call, I load the function name according to div position using

$('section div.graph_box').each(function(){
                                if ($(this).css('display')=='block') {
                                    graphName.push($(this).attr('id'));
                                }
                            });

where graphName is global and stores the name of divs in sequence. LoadGraphInSeq is then called at every end of ajax functions to call next function call.

function loadGraphInSeq(startDate,endDate,calcSubStart,calcSubEnd,graphNametoCall){
                switch (graphNametoCall) {
                    case 'allquery':
                        return(loadGraphInSeq(startDate,endDate,calcSubStart,calcSubEnd,graphName[graphname++]));
                    case 'ajaxCallingAlwazIncr':
                        ajaxCallingAlwazIncr(calcSubStart,calcSubEnd,startDate,endDate);
                        return(loadGraphInSeq(startDate,endDate,calcSubStart,calcSubEnd,graphName[graphname++]));
                    case 'segment':
                        return 'ajaxCallingSegment';
                    case 'answeredresponse':
                        return 'ajaxCallingSegmentRespDay';
                    case 'segmentresponse':
                        return 'ajaxCallingSegmentRespHours';
                    case 'lessthanDonut':
                        return 'ajaxCallinglessthanDonut';
                    case 'carrierPie':
                        return 'ajaxCallingCarrierPie';
                    default:
                        return 0;
                }
        }

This is the code which I have written after every function

 funcToCall=loadGraphInSeq(startDate,endDate,calcSubStart,calcSubEnd,graphName[graphname++]);
                     if (funcToCall!=0) {
                        var strParam = "startDate,endDate,calcSubStart,calcSubEnd";
                        var funcCall = funcToCall + "(" + strParam + ");";
                        eval(funcCall);
                    }