react app

react-app/node_modules/react/lib/ReactFragment.js

@@ -0,0 +1,181 @@
+/**
+ * Copyright 2015, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+* @providesModule ReactFragment
+*/
+
+'use strict';
+
+var ReactElement = require("./ReactElement");
+
+var warning = require("./warning");
+
+/**
+ * We used to allow keyed objects to serve as a collection of ReactElements,
+ * or nested sets. This allowed us a way to explicitly key a set a fragment of
+ * components. This is now being replaced with an opaque data structure.
+ * The upgrade path is to call React.addons.createFragment({ key: value }) to
+ * create a keyed fragment. The resulting data structure is opaque, for now.
+ */
+
+if ("production" !== process.env.NODE_ENV) {
+  var fragmentKey = '_reactFragment';
+  var didWarnKey = '_reactDidWarn';
+  var canWarnForReactFragment = false;
+
+  try {
+    // Feature test. Don't even try to issue this warning if we can't use
+    // enumerable: false.
+
+    var dummy = function() {
+      return 1;
+    };
+
+    Object.defineProperty(
+      {},
+      fragmentKey,
+      {enumerable: false, value: true}
+    );
+
+    Object.defineProperty(
+      {},
+      'key',
+      {enumerable: true, get: dummy}
+    );
+
+    canWarnForReactFragment = true;
+  } catch (x) { }
+
+  var proxyPropertyAccessWithWarning = function(obj, key) {
+    Object.defineProperty(obj, key, {
+      enumerable: true,
+      get: function() {
+        ("production" !== process.env.NODE_ENV ? warning(
+          this[didWarnKey],
+          'A ReactFragment is an opaque type. Accessing any of its ' +
+          'properties is deprecated. Pass it to one of the React.Children ' +
+          'helpers.'
+        ) : null);
+        this[didWarnKey] = true;
+        return this[fragmentKey][key];
+      },
+      set: function(value) {
+        ("production" !== process.env.NODE_ENV ? warning(
+          this[didWarnKey],
+          'A ReactFragment is an immutable opaque type. Mutating its ' +
+          'properties is deprecated.'
+        ) : null);
+        this[didWarnKey] = true;
+        this[fragmentKey][key] = value;
+      }
+    });
+  };
+
+  var issuedWarnings = {};
+
+  var didWarnForFragment = function(fragment) {
+    // We use the keys and the type of the value as a heuristic to dedupe the
+    // warning to avoid spamming too much.
+    var fragmentCacheKey = '';
+    for (var key in fragment) {
+      fragmentCacheKey += key + ':' + (typeof fragment[key]) + ',';
+    }
+    var alreadyWarnedOnce = !!issuedWarnings[fragmentCacheKey];
+    issuedWarnings[fragmentCacheKey] = true;
+    return alreadyWarnedOnce;
+  };
+}
+
+var ReactFragment = {
+  // Wrap a keyed object in an opaque proxy that warns you if you access any
+  // of its properties.
+  create: function(object) {
+    if ("production" !== process.env.NODE_ENV) {
+      if (typeof object !== 'object' || !object || Array.isArray(object)) {
+        ("production" !== process.env.NODE_ENV ? warning(
+          false,
+          'React.addons.createFragment only accepts a single object.',
+          object
+        ) : null);
+        return object;
+      }
+      if (ReactElement.isValidElement(object)) {
+        ("production" !== process.env.NODE_ENV ? warning(
+          false,
+          'React.addons.createFragment does not accept a ReactElement ' +
+          'without a wrapper object.'
+        ) : null);
+        return object;
+      }
+      if (canWarnForReactFragment) {
+        var proxy = {};
+        Object.defineProperty(proxy, fragmentKey, {
+          enumerable: false,
+          value: object
+        });
+        Object.defineProperty(proxy, didWarnKey, {
+          writable: true,
+          enumerable: false,
+          value: false
+        });
+        for (var key in object) {
+          proxyPropertyAccessWithWarning(proxy, key);
+        }
+        Object.preventExtensions(proxy);
+        return proxy;
+      }
+    }
+    return object;
+  },
+  // Extract the original keyed object from the fragment opaque type. Warn if
+  // a plain object is passed here.
+  extract: function(fragment) {
+    if ("production" !== process.env.NODE_ENV) {
+      if (canWarnForReactFragment) {
+        if (!fragment[fragmentKey]) {
+          ("production" !== process.env.NODE_ENV ? warning(
+            didWarnForFragment(fragment),
+            'Any use of a keyed object should be wrapped in ' +
+            'React.addons.createFragment(object) before being passed as a ' +
+            'child.'
+          ) : null);
+          return fragment;
+        }
+        return fragment[fragmentKey];
+      }
+    }
+    return fragment;
+  },
+  // Check if this is a fragment and if so, extract the keyed object. If it
+  // is a fragment-like object, warn that it should be wrapped. Ignore if we
+  // can't determine what kind of object this is.
+  extractIfFragment: function(fragment) {
+    if ("production" !== process.env.NODE_ENV) {
+      if (canWarnForReactFragment) {
+        // If it is the opaque type, return the keyed object.
+        if (fragment[fragmentKey]) {
+          return fragment[fragmentKey];
+        }
+        // Otherwise, check each property if it has an element, if it does
+        // it is probably meant as a fragment, so we can warn early. Defer,
+        // the warning to extract.
+        for (var key in fragment) {
+          if (fragment.hasOwnProperty(key) &&
+              ReactElement.isValidElement(fragment[key])) {
+            // This looks like a fragment object, we should provide an
+            // early warning.
+            return ReactFragment.extract(fragment);
+          }
+        }
+      }
+    }
+    return fragment;
+  }
+};
+
+module.exports = ReactFragment;