[FIXED] Creating a pass-through field with Model Serializer: Django

Issue

I am new to Django Rest Framework and appreciate the help from this community. I am making an AJAX call to some Django Rest Framework APIs in the backend and I would like to pass the name of the javascript function to be called in the UI upon successful completion of the request.

AJAX Function

var saveEditedData = function (event) {
    let parentElement = event.parentElement;
    let enctype = (event.enctype) ? event.enctype : "application/x-www-form-urlencoded";
    let method = (event.method) ? event.method : "POST";

    $.ajax({
        cache: false,
        contentType: false,
        data: event.data,
        enctype: enctype,
        processData: false,
        type: method,
        url: event.url,
        success: function (response){
            console.log(response);
            if (response['onSuccessFn']){
                successFns[response['onSuccessFn']](response);
            } 
        },
        error: function (response) {
            let errors = response["responseJSON"]["errors"];
            displayErrors(parentElement, errors);
        }
    });
}

DJANGO REST Serializer Class

class DocumentCategorySerializer(serializers.ModelSerializer):
    id = serializers.ReadOnlyField()
    on_success_fn = serializers.SerializerMethodField()

    class Meta:
        model = DocumentCategory
        fields = ['id', 'name', 'description', 'on_success_fn']

    def get_on_success_fn(self, obj):
        return self.data['on_success_fn']

**Sample Inbound Data to Serializer**
[name : TestCategory]
[description: Testing this]
[on_success_fn: addCategorySuccessFn]

The idea is that I use one AJAX function across multiple UI interactions and the method to be called on success is dynamically executed on return. I have a model serializer but all the fields are derived from the database. I added a SerializerMethodField but it doesn't pass through the input value. I need one field to be a 'pass-through' - it just sends the same value it received in input to output.

Question: How do I pass a field inbound and outbound to Django Rest Framework?

Solution

self.data is actually a method, you will end up in a infinite recursion if you call it from a field. Use self.initial_data instead.

class DocumentCategorySerializer(serializers.ModelSerializer): 
    on_success_fn = serializers.SerializerMethodField()

    class Meta:
        model = DocumentCategory
        fields = ['id', 'name', 'description', 'on_success_fn']
        read_only_field = ('id',)

    def get_on_success_fn(self, obj):
        return self.initial_data['on_success_fn']

Answered By - Julkar9