#547 Add a 'getValue' function to mimic the Web API's 'once'

Author: EddyVerbruggen

src/firebase.android.ts

@@ -924,6 +924,7 @@ function toLoginResult(user) {
     // provider: user.getProviderId(), // always 'firebase'
     providers: providers,
     anonymous: user.isAnonymous(),
+    isAnonymous: user.isAnonymous(),
     phoneNumber: user.getPhoneNumber(),
     profileImageURL: user.getPhotoUrl() ? user.getPhotoUrl().toString() : null
   };
@@ -1514,6 +1515,25 @@ firebase.addValueEventListener = (updateCallback, path) => {
   });
 };
 
+firebase.getValue = path => {
+  return new Promise((resolve, reject) => {
+    try {
+      const listener = new com.google.firebase.database.ValueEventListener({
+        onDataChange: snapshot => {
+          resolve(firebase.getCallbackData('ValueChanged', snapshot));
+        },
+        onCancelled: databaseError => {
+          reject(databaseError.getMessage());
+        }
+      });
+      firebase.instance.child(path).addListenerForSingleValueEvent(listener);
+    } catch (ex) {
+      console.log("Error in firebase.getValue: " + ex);
+      reject(ex);
+    }
+  });
+};
+
 firebase.removeEventListeners = (listeners, path) => {
   return new Promise((resolve, reject) => {
     try {

src/firebase.d.ts

@@ -268,6 +268,7 @@ export interface User {
   name?: string;
   phoneNumber?: string;
   anonymous: boolean;
+  isAnonymous: boolean; // This is used by the web API
   providers: Array<Provider>;
   profileImageURL?: string;
   /** iOS only */
@@ -539,6 +540,8 @@ export function init(options?: InitOptions): Promise<any>;
 // Database
 export function push(path: string, value: any): Promise<PushResult>;
 
+export function getValue(path: string): Promise<any>;
+
 export function setValue(path: string, value: any): Promise<any>;
 
 export function update(path: string, value: any): Promise<any>;

src/firebase.ios.ts

@@ -583,7 +583,7 @@ firebase.toJsObject = objCObj => {
   return node;
 };
 
-firebase.getCallbackData = (type, snapshot) => {
+firebase.getCallbackData = (type, snapshot: FIRDataSnapshot) => {
   return {
     type: type,
     key: snapshot.key,
@@ -1090,6 +1090,7 @@ function toLoginResult(user) {
   return {
     uid: user.uid,
     anonymous: user.anonymous,
+    isAnonymous: user.anonymous,
     // provider: user.providerID, // always 'Firebase'
     providers: providers,
     profileImageURL: user.photoURL ? user.photoURL.absoluteString : null,
@@ -1639,6 +1640,25 @@ firebase.addValueEventListener = (updateCallback, path) => {
   });
 };
 
+firebase.getValue = path => {
+  return new Promise((resolve, reject) => {
+    try {
+      const where = path === undefined ? firebase.instance : firebase.instance.childByAppendingPath(path);
+      const listener = where.observeSingleEventOfTypeWithBlockWithCancelBlock(
+          FIRDataEventType.Value,
+          snapshot => {
+            resolve(firebase.getCallbackData('ValueChanged', snapshot));
+          },
+          firebaseError => {
+            reject(firebaseError.localizedDescription);
+          });
+    } catch (ex) {
+      console.log("Error in firebase.getValue: " + ex);
+      reject(ex);
+    }
+  });
+};
+
 firebase.removeEventListeners = (listeners, path) => {
   return new Promise((resolve, reject) => {
     try {