Initial commit

node_modules/history/createTransitionManager.js

@@ -0,0 +1,85 @@
+'use strict';
+
+exports.__esModule = true;
+
+var _warning = require('warning');
+
+var _warning2 = _interopRequireDefault(_warning);
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+var createTransitionManager = function createTransitionManager() {
+  var prompt = null;
+
+  var setPrompt = function setPrompt(nextPrompt) {
+    (0, _warning2.default)(prompt == null, 'A history supports only one prompt at a time');
+
+    prompt = nextPrompt;
+
+    return function () {
+      if (prompt === nextPrompt) prompt = null;
+    };
+  };
+
+  var confirmTransitionTo = function confirmTransitionTo(location, action, getUserConfirmation, callback) {
+    // TODO: If another transition starts while we're still confirming
+    // the previous one, we may end up in a weird state. Figure out the
+    // best way to handle this.
+    if (prompt != null) {
+      var result = typeof prompt === 'function' ? prompt(location, action) : prompt;
+
+      if (typeof result === 'string') {
+        if (typeof getUserConfirmation === 'function') {
+          getUserConfirmation(result, callback);
+        } else {
+          (0, _warning2.default)(false, 'A history needs a getUserConfirmation function in order to use a prompt message');
+
+          callback(true);
+        }
+      } else {
+        // Return false from a transition hook to cancel the transition.
+        callback(result !== false);
+      }
+    } else {
+      callback(true);
+    }
+  };
+
+  var listeners = [];
+
+  var appendListener = function appendListener(fn) {
+    var isActive = true;
+
+    var listener = function listener() {
+      if (isActive) fn.apply(undefined, arguments);
+    };
+
+    listeners.push(listener);
+
+    return function () {
+      isActive = false;
+      listeners = listeners.filter(function (item) {
+        return item !== listener;
+      });
+    };
+  };
+
+  var notifyListeners = function notifyListeners() {
+    for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
+      args[_key] = arguments[_key];
+    }
+
+    listeners.forEach(function (listener) {
+      return listener.apply(undefined, args);
+    });
+  };
+
+  return {
+    setPrompt: setPrompt,
+    confirmTransitionTo: confirmTransitionTo,
+    appendListener: appendListener,
+    notifyListeners: notifyListeners
+  };
+};
+
+exports.default = createTransitionManager;