JSONAPI-inheriting FormData adapter

form-data.js

import Ember from 'ember';
import ApplicationAdapter from './application';

export default ApplicationAdapter.extend({
  // only convert to FormData for the following http methods:
  methods: ['POST', 'PATCH', 'PUT'],

  ajaxOptions(url, type, options) {
    let unserializedData = options && options.data;
    let hash = this._super(...arguments);

    if (unserializedData && this.methods.contains(type)) {
      hash.processData = false;
      hash.contentType = false;
      let formData = new FormData();
      let serializeFormData = (keyPath, data) => {
        for (let key in data) {
          let newKeyPath = `${keyPath}[${key}]`;
          let value = data[key];
          if (value) {
            if (Ember.$.isPlainObject(value)) {
              serializeFormData(newKeyPath, value);
            } else {
              formData.append(newKeyPath, value);
            }
          }
        }
      };
      let root = Object.keys(unserializedData)[0];
      let data = unserializedData[root];
      serializeFormData(root, data);
      hash.data = formData;
    }

    return hash;
  }
});

in the rails-server, which uses the jsonapi-resources gem, i had to do some finagling since it breaks the JSON-API format. any actions receiving modified calls need skip_before_action :ensure_correct_media_type and some implementation tweaks. e.g. after manually creating/updating the model instance:

serializer = JSONAPI::ResourceSerializer.new(resource_klass)
model_resource = resource_klass.new(model_instance, nil)
render json: serializer.serialize_to_hash(model_resource)