[FIXED] How to Identify a Name of JSON object?

Issue

I'm trying to create a method to improve performance inserting in database. We work with asp net and use javascript/jquery/ajax on web.

First i created a function to get a form, but i want to use this method to different forms.

So my html is something like:

<form id="myForm">
    <input type="hidden" name="TableId" value="@Model.TableId" />
    <label for="Name"></label>
    <input class="form-control" type="text" name="Name" id="Name" />
</form>

So the form go to controller, insert in database and the return of the controller is something like:

string json = JsonConvert.SerializeObject(object);

return new JsonResult(json);

and ajax:

$.ajax({
  type: 'POST',
  url: '/Controller/Action',
  dataType: 'json',
  contentType: 'application/x-www-form-urlencoded; charset=UTF-8',
  data: myForm,
  success: function (data) {
    let jsonData = $.parseJSON(data);
    // The next line is what i want to change
    let myId = jsonData.TableId;
  }
});

The issue is that the object returned by json will always have a different name because I want to use this same code in several forms.

For example:

If I use it in the Car table form, I need to get the primary key of the Car table, which would be CarId.

If I use it in the People table form, I need the value that will come from the object as data.PersonId.

I already know how to get the name of the primary key, but I can't concatenate it within ajax with the name of the object.

It would be something like:

let primaryKeyName = 'tableName' + 'Id';
let primaryKeyValue = data. + primaryKeyName;

I need to concatenate a string that i generate with the name of object.

Solution

This should work using a mapping table:

const tableToKeyMap = {
  Car:    'CarId',
  People: 'PersonId'
}

function getJsonValue(data, tableName) {
  let key = tableToKeyMap[tableName];
  return data[key] || 'not found';
}

const dataFromJson = {
  CarId:    'Toyota',
  PersonId: 'Jane',
  OtherId:  'foo'
}

console.log('Car => ' + getJsonValue(dataFromJson, 'Car'));
console.log('People => ' + getJsonValue(dataFromJson, 'People'));
console.log('Oops => ' + getJsonValue(dataFromJson, 'Oops'));

Output:

Car => Toyota
People => Jane
Oops => not found

Answered By - Peter Thoeny

Answer Checked By - Gilberto Lyons (PHPFixing Admin)