react-router/es/getComponents.js

A complete routing library for React

import { mapAsync } from './AsyncUtils';
import { isPromise } from './PromiseUtils';

function getComponentsForRoute(nextState, route, callback) {
  if (route.component || route.components) {
    callback(null, route.component || route.components);
    return;
  }

  var getComponent = route.getComponent || route.getComponents;
  if (getComponent) {
    var componentReturn = getComponent.call(route, nextState, callback);
    if (isPromise(componentReturn)) componentReturn.then(function (component) {
      return callback(null, component);
    }, callback);
  } else {
    callback();
  }
}

/**
 * Asynchronously fetches all components needed for the given router
 * state and calls callback(error, components) when finished.
 *
 * Note: This operation may finish synchronously if no routes have an
 * asynchronous getComponents method.
 */
function getComponents(nextState, callback) {
  mapAsync(nextState.routes, function (route, index, callback) {
    getComponentsForRoute(nextState, route, callback);
  }, callback);
}

export default getComponents;