create-react-context/lib/implementation.js

'use strict';

exports.__esModule = true;

var _react = require('react');

var _react2 = _interopRequireDefault(_react);

var _propTypes = require('prop-types');

var _propTypes2 = _interopRequireDefault(_propTypes);

var _gud = require('gud');

var _gud2 = _interopRequireDefault(_gud);

var _warning = require('warning');

var _warning2 = _interopRequireDefault(_warning);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

var MAX_SIGNED_31_BIT_INT = 1073741823;

// Inlined Object.is polyfill.
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is
function objectIs(x, y) {
  if (x === y) {
    return x !== 0 || 1 / x === 1 / y;
  } else {
    return x !== x && y !== y;
  }
}

function createEventEmitter(value) {
  var handlers = [];
  return {
    on: function on(handler) {
      handlers.push(handler);
    },
    off: function off(handler) {
      handlers = handlers.filter(function (h) {
        return h !== handler;
      });
    },
    get: function get() {
      return value;
    },
    set: function set(newValue, changedBits) {
      value = newValue;
      handlers.forEach(function (handler) {
        return handler(value, changedBits);
      });
    }
  };
}

function onlyChild(children) {
  return Array.isArray(children) ? children[0] : children;
}

function createReactContext(defaultValue, calculateChangedBits) {
  var _Provider$childContex, _Consumer$contextType;

  var contextProp = '__create-react-context-' + (0, _gud2.default)() + '__';

  var Provider = function (_Component) {
    _inherits(Provider, _Component);

    function Provider() {
      var _temp, _this, _ret;

      _classCallCheck(this, Provider);

      for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
        args[_key] = arguments[_key];
      }

      return _ret = (_temp = (_this = _possibleConstructorReturn(this, _Component.call.apply(_Component, [this].concat(args))), _this), _this.emitter = createEventEmitter(_this.props.value), _temp), _possibleConstructorReturn(_this, _ret);
    }

    Provider.prototype.getChildContext = function getChildContext() {
      var _ref;

      return _ref = {}, _ref[contextProp] = this.emitter, _ref;
    };

    Provider.prototype.componentWillReceiveProps = function componentWillReceiveProps(nextProps) {
      if (this.props.value !== nextProps.value) {
        var oldValue = this.props.value;
        var newValue = nextProps.value;
        var changedBits = void 0;

        if (objectIs(oldValue, newValue)) {
          changedBits = 0; // No change
        } else {
          changedBits = typeof calculateChangedBits === 'function' ? calculateChangedBits(oldValue, newValue) : MAX_SIGNED_31_BIT_INT;
          if (process.env.NODE_ENV !== 'production') {
            (0, _warning2.default)((changedBits & MAX_SIGNED_31_BIT_INT) === changedBits, 'calculateChangedBits: Expected the return value to be a ' + '31-bit integer. Instead received: %s', changedBits);
          }

          changedBits |= 0;

          if (changedBits !== 0) {
            this.emitter.set(nextProps.value, changedBits);
          }
        }
      }
    };

    Provider.prototype.render = function render() {
      return this.props.children;
    };

    return Provider;
  }(_react.Component);

  Provider.childContextTypes = (_Provider$childContex = {}, _Provider$childContex[contextProp] = _propTypes2.default.object.isRequired, _Provider$childContex);

  var Consumer = function (_Component2) {
    _inherits(Consumer, _Component2);

    function Consumer() {
      var _temp2, _this2, _ret2;

      _classCallCheck(this, Consumer);

      for (var _len2 = arguments.length, args = Array(_len2), _key2 = 0; _key2 < _len2; _key2++) {
        args[_key2] = arguments[_key2];
      }

      return _ret2 = (_temp2 = (_this2 = _possibleConstructorReturn(this, _Component2.call.apply(_Component2, [this].concat(args))), _this2), _this2.state = {
        value: _this2.getValue()
      }, _this2.onUpdate = function (newValue, changedBits) {
        var observedBits = _this2.observedBits | 0;
        if ((observedBits & changedBits) !== 0) {
          _this2.setState({ value: _this2.getValue() });
        }
      }, _temp2), _possibleConstructorReturn(_this2, _ret2);
    }

    Consumer.prototype.componentWillReceiveProps = function componentWillReceiveProps(nextProps) {
      var observedBits = nextProps.observedBits;

      this.observedBits = observedBits === undefined || observedBits === null ? MAX_SIGNED_31_BIT_INT // Subscribe to all changes by default
      : observedBits;
    };

    Consumer.prototype.componentDidMount = function componentDidMount() {
      if (this.context[contextProp]) {
        this.context[contextProp].on(this.onUpdate);
      }
      var observedBits = this.props.observedBits;

      this.observedBits = observedBits === undefined || observedBits === null ? MAX_SIGNED_31_BIT_INT // Subscribe to all changes by default
      : observedBits;
    };

    Consumer.prototype.componentWillUnmount = function componentWillUnmount() {
      if (this.context[contextProp]) {
        this.context[contextProp].off(this.onUpdate);
      }
    };

    Consumer.prototype.getValue = function getValue() {
      if (this.context[contextProp]) {
        return this.context[contextProp].get();
      } else {
        return defaultValue;
      }
    };

    Consumer.prototype.render = function render() {
      return onlyChild(this.props.children)(this.state.value);
    };

    return Consumer;
  }(_react.Component);

  Consumer.contextTypes = (_Consumer$contextType = {}, _Consumer$contextType[contextProp] = _propTypes2.default.object, _Consumer$contextType);


  return {
    Provider: Provider,
    Consumer: Consumer
  };
}

exports.default = createReactContext;
module.exports = exports['default'];