解析云代码循环仅通过第一个实例

Question

I want the following loop to go through every instance of matchCenterItem , yet for some reason, it pings ebay using the properties of only the first instance. The console logs at the end of the function however, loop through all instances and log their respective properties.

  Parse.Cloud.define("MatchCenterTest", function(request, response) {

  var matchCenterItem = Parse.Object.extend("matchCenterItem");
  var query = new Parse.Query(matchCenterItem);

  var promises = [];

  query.limit(10);
  query.find().then(function(results) {
    for (i=0; i<results.length; i++) {

      url = 'http://svcs.ebay.com/services/search/FindingService/v1';
       promises.push(Parse.Cloud.httpRequest({
        url: url,
        params: {   
         'OPERATION-NAME' : 'findItemsByKeywords', 
         'SERVICE-VERSION' : '1.12.0',
         'SECURITY-APPNAME' : '*App ID goes here*',
         'GLOBAL-ID' : 'EBAY-US',
         'RESPONSE-DATA-FORMAT' : 'JSON',
         'REST-PAYLOAD&sortOrder' : 'BestMatch',
         'paginationInput.entriesPerPage' : '3',
         'outputSelector=AspectHistogram&itemFilter(0).name=Condition&itemFilter(0).value(0)' : results[i].get('itemCondition'),
         'itemFilter(1).name=MaxPrice&itemFilter(1).value' : results[i].get('maxPrice'),
         'itemFilter(1).paramName=Currency&itemFilter(1).paramValue' : 'USD',
         'itemFilter(2).name=MinPrice&itemFilter(2).value' : results[i].get('minPrice'),
         'itemFilter(2).paramName=Currency&itemFilter(2).paramValue' : 'USD',
         //'itemFilter(3).name=LocatedIn&itemFilter(3).Value' : request.params.itemLocation,
         'itemFilter(3).name=ListingType&itemFilter(3).value' : 'FixedPrice',
         'keywords' : results[i].get('searchTerm'),
        },
        // success: function (httpResponse) {
        //   // parses results
        //   var httpresponse = JSON.parse(httpResponse.text);

        //   response.success(httpresponse);
        //   console.log('MatchCenter Pinged eBay dude!');
        // },
        // error: function (httpResponse) {
        //   console.log('error!!!');
        //   response.error('Request failed with response code ' + httpResponse.status);
        // }
      }));

     console.log(results[i].get('itemCondition'));
     console.log(results[i].get('maxPrice'));
     console.log(results[i].get('minPrice'));
     console.log(results[i].get('searchTerm'));

    }
  });

Parse.Promise.when(promises).then(function(results) {

   var httpresponse = JSON.parse(httpResponse.text);
   response.success(httpresponse);
}, function(err) {
    console.log('error!!!');
});



});

Answer 1

This is because the http request is asynchronous, and you're calling response.success in the completion handler for the first (and all) requests. Use the promise syntax and only complete when they are done. Simplified concept:

var promises = [];
for (...) {
   promises.push(Parse.Cloud.httpRequest({...}));  // no success/error params
}
Parse.Promise.when(promises).then(function(results) {
   response.success(...);
}, function(err) {

});