Convert one object to another in Angular 7

Question

I am using Angular 7 and I am getting all details into const fieldErrors = error.error.fieldErrors;

0:
code: "Size"
field: "studentName"
message: "Length of characters should be between 1 to 255"
resource: "studentDto"
__proto__: Object
1:
code: "NotBlank"
field: "studentName"
message: "Program Name is mandatory"
resource: "studentDto"
__proto__: Object
2:
code: "NotBlank"
field: "studentDesc"
message: "Student Description is mandatory"
resource: "studentDto"
__proto__: Object
length: 3

I want to convert it into the

ServerResponse = {
   "studentName" {
        "Program Name is mandatory"
    },
    studentDesc {
       "Student Description is mandatory"
   }
}

Answer 1

You might probably want to convert it into a json with each field being an array, like below:

ServerResponse = {
    studentName: [
        "Length of characters should be between 1 to 255",
        "Program Name is mandatory"
    ],
    studentDesc: [
        "Student Description is mandatory"
    ]
}

In this way, multiple error messages for the same field can be fit into the same key.

You can loop through the fieldErrors array and manually assign the values.

let ServerResponse = {};
fieldErrors.forEach(fieldError => {
    if (ServerResponse[fieldError.field]) {
        ServerResponse[fieldError.field].push(fieldError.message);
    } else {
        ServerResponse[fieldError.field] = fieldError.message;
    }
});

If the field is already present in ServerResponse, you are adding the message to the list. If the field is not present, make a new entry.