What is transformRequest in angularjs - angularjs

Question

I have a code
transformRequest: function(obj) {
var str = [];
for(var p in obj)
str.push(encodeURIComponent(p) + "=" + encodeURIComponent(obj[p]));
return str.join("&");
}
I know this code is change the serialization algorithm and post the data with the content-type, "application/x-www-form-urlencoded". But i dont know what is syntax of it . What is obj in function . Please explain for me . Thank

Answer 1

Transform Request is generally used for converting request data in the format which can be easily handled by server (Your Back end code).
For Example - If you want to send data with some modification in request then you can use it .
$scope.save = function() {
$http({
method: 'POST',
url: "/Api/PostStuff",
//IMPORTANT!!! You might think this should be set to 'multipart/form-data'
// but this is not true because when we are sending up files the request
// needs to include a 'boundary' parameter which identifies the boundary
// name between parts in this multi-part request and setting the Content-type
// manually will not set this boundary parameter. For whatever reason,
// setting the Content-type to 'undefined' will force the request to automatically
// populate the headers properly including the boundary parameter.
headers: { 'Content-Type': undefined},
//This method will allow us to change how the data is sent up to the server
// for which we'll need to encapsulate the model data in 'FormData'
transformRequest: function (data) {
var formData = new FormData();
//need to convert our json object to a string version of json otherwise
// the browser will do a 'toString()' on the object which will result
// in the value '[Object object]' on the server.
formData.append("model", angular.toJson(data.model));
//now add all of the assigned files
for (var i = 0; i < data.files; i++) {
//add each file to the form data and iteratively name them
formData.append("file" + i, data.files[i]);
}
return formData;
},
//Create an object that contains the model and files which will be transformed
// in the above transformRequest method
data: { model: $scope.model, files: $scope.files }
}).
success(function (data, status, headers, config) {
alert("success!");
}).
error(function (data, status, headers, config) {
alert("failed!");
});
};
};