relay-utils/lib/createMissingFieldsHandler.js

Utilities for working with Relay (modern) in general, and the Relay store in particular.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.createMissingFieldsHandler = createMissingFieldsHandler;

/**
 * A small abstraction over the missingFieldHandlers prop on Environment.
 * Lets your set up own strategies for resolving missing fields in responses.
 */
function processHandlers(handlers, field, record, args, store) {
  for (var i = 0; i <= handlers.length - 1; i += 1) {
    var handledVal = handlers[i]({
      name: field.name,
      alias: field.alias,
      fieldArgs: field.args || null,
      args: args,
      ownerTypename: record && record.__typename && typeof record.__typename === 'string' ? record.__typename : null,
      owner: record,
      store: store
    });

    if (typeof handledVal !== 'undefined') {
      return handledVal;
    }
  }
}

function createMissingFieldsHandler(config) {
  return [{
    kind: 'scalar',
    handle: function handle(field, record, args, store) {
      if (config.handleScalarField) {
        return processHandlers(config.handleScalarField, field, record, args, store);
      }
    }
  }, {
    kind: 'linked',
    handle: function handle(field, record, args, store) {
      if (config.handleLinkedField) {
        return processHandlers(config.handleLinkedField, field, record, args, store);
      }
    }
  }, {
    kind: 'pluralLinked',
    handle: function handle(field, record, args, store) {
      if (config.handlePluralLinkedField) {
        return processHandlers(config.handlePluralLinkedField, field, record, args, store);
      }
    }
  }];
}