@applicaster/zapp-react-native-utils/reactUtils/createContext/helpers.ts

Applicaster Zapp React Native utilities package

import * as R from "ramda";
import { capitalize } from "../../stringUtils";

import { reactUtilsLogger } from "../logger";

const logger = reactUtilsLogger.addSubsystem("CreateContext");

const SETTER_PREFIX = "set";

// this noop function is used temporarily when the React Context is first created
export const NOOP = () => {};

/**
 * gets the setter name for a given property : fooBar => setFooBar
 * @param property
 * @returns
 */
export const getSetterName: (property: string) => string = R.compose(
  R.concat(SETTER_PREFIX),
  capitalize
);

/**
 * Creates the setter function for each property, and binds it to the current react component,
 * invokes the stateValidator if provided in the options
 * @param properties array of properties for which setters need to be created
 * @param component react component to which the setter functions must be bound to
 * @param options
 * @param options.stateValidator optional Predicate to validate whether
 * the invokation of the setter is valid or not. It is called with {property, value}
 * falls back to () => true if not provided
 */
export function createContextSetters(
  properties: string[],
  component: any,
  options: any = {}
) {
  const { stateValidator = R.T } = options;

  R.forEach((property) => {
    const setterName = getSetterName(property);

    component[setterName] = (value) => {
      const oldValue = component.state[property];

      if (oldValue === value) {
        return;
      }

      if (stateValidator({ property, value }, oldValue)) {
        component.setState(R.assoc(property, value));
      } else {
        logger.warning(
          `trying to invoke ${setterName} with ${value} - but it was rejected by the state validator
          skipping context update`
        );
      }
    };
  }, properties);
}