function declarations for success and error handling within the service's controller

Question

function declarations for success and error handling within the service's controller

Here is the code snippet for a service that includes a fetchData function being called from a controller.

In the Service:


app.service("geturl", function($http) {
    urllist = [];
    geturl.fetchData = function() {
        var data = [];
        for (i = 0; i < urllist.length; i++) {
            (function(index) {
                return $http.get(geturl.urllist[index], {
                    timeout: 8000
                })
                .then(function(response) {
                    data[index] = response.data;
                });
            }(i);
            return data;
        });
    };
});

I need to handle the success and error functions of $http.get in the controller to be used in the UI. How should I approach this?

javascript angularjs angularjs-service angularjs-http angular-promise

Answer 1

Answer №1

When it comes to writing the success and error functions for $http.get in the controller...

The usual way is to use the .then() function with two function arguments - the first as the success handler, and the second as the error handler.

$http.get(url,options).then(function (response){
    //success handler function
    },function(error){
  //error handler function     
  })

Alternatively, you can also define the .success and .error functions separately.

$http.get(url,options).success(function (response){
    //success handler function
    }).error(function(error){
  //error handler function     
  })

A tip: Instead of returning something directly from your service's geturl method and defining callbacks there, it's better practice to return a promise from the service itself.

   ... 
   app.service("geturl",function($http){
     ...
     getData:function(){
        return $http.get(url,options);
     }
     ...               
   });
   ...

Then, handle the success/error callbacks in the module where you are using/consuming the service.

geturl.getData().success(function(){
//handle success
}).error(function(){
//handle error
})

And remember, when dealing with multiple http requests, avoid using for loops. Since everything is asynchronous, it's important to use tools like AngularJS's $q service for handling such scenarios effectively. Check out @pankajparkar's answer for more insights.

Answer 2

When it comes to writing the success and error functions for $http.get in the controller...

The usual way is to use the .then() function with two function arguments - the first as the success handler, and the second as the error handler.

$http.get(url,options).then(function (response){
    //success handler function
    },function(error){
  //error handler function     
  })

Alternatively, you can also define the .success and .error functions separately.

$http.get(url,options).success(function (response){
    //success handler function
    }).error(function(error){
  //error handler function     
  })

A tip: Instead of returning something directly from your service's geturl method and defining callbacks there, it's better practice to return a promise from the service itself.

   ... 
   app.service("geturl",function($http){
     ...
     getData:function(){
        return $http.get(url,options);
     }
     ...               
   });
   ...

Then, handle the success/error callbacks in the module where you are using/consuming the service.

geturl.getData().success(function(){
//handle success
}).error(function(){
//handle error
})

And remember, when dealing with multiple http requests, avoid using for loops. Since everything is asynchronous, it's important to use tools like AngularJS's $q service for handling such scenarios effectively. Check out @pankajparkar's answer for more insights.

Answer 3

Answer №2

It appears that you are looking to retrieve data once all ajax requests have finished. One way to accomplish this is by utilizing the $q.all() method.

Data Retrieval Service

app.service("getData", function($http, $q) {
    this.dataList = [];
    this.fetchData = function() {
        var data = [], promises = [];
        
        for (i = 0; i < dataList.length; i++) {
          (function(index) {
            var promise = $http.get(getData.dataList[index], {
              timeout: 8000
            })
            .then(function(response) {
              data[index] = response.data;
            });
            
            promises.push(promise); // add promise to array
          }(i);
        };
        
        return $q.all(promises).then(function(resp){ 
            return data; // return data after all promises have completed
        });
    };
});

Answer 4

It appears that you are looking to retrieve data once all ajax requests have finished. One way to accomplish this is by utilizing the $q.all() method.

Data Retrieval Service

app.service("getData", function($http, $q) {
    this.dataList = [];
    this.fetchData = function() {
        var data = [], promises = [];
        
        for (i = 0; i < dataList.length; i++) {
          (function(index) {
            var promise = $http.get(getData.dataList[index], {
              timeout: 8000
            })
            .then(function(response) {
              data[index] = response.data;
            });
            
            promises.push(promise); // add promise to array
          }(i);
        };
        
        return $q.all(promises).then(function(resp){ 
            return data; // return data after all promises have completed
        });
    };
});

function declarations for success and error handling within the service's controller

Answer №1

Answer №2

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