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Anant Narayanan anantn

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anantn / firebase_remove_pushed.js
Last active February 19, 2019 23:45
Firebase: Removing an item you've pushed. This snippet shows how to remove an object that you just added using push().
function pushSomething(ref) {
// Let's push something. push() returns a reference that you can hold onto!
var justPushed = ref.push({test: "push"});
// We return a reference, but you can also return the name of the newly
// created object with .name().
return justPushed;
}
function removeItem(ref) {
// Now we can get back to that item we just pushed via .child().
@anantn
anantn / firebase_snapshot_parent.js
Last active April 14, 2021 15:29
Firebase: Get the parent of a snapshot.
function getParent(snapshot) {
// You can get the reference (A Firebase object) from a snapshot
// using .ref().
var ref = snapshot.ref();
// Now simply find the parent and return the name.
return ref.parent().name();
}
var testRef = new Firebase("https://example.firebaseIO-demo.com/foo/bar");
testRef.once("value", function(snapshot) {
@anantn
anantn / getusermedia_picture.html
Created February 17, 2012 09:12
Take a picture with getUserMedia
<html>
<body>
<video id="v" width="300" height="300"></video>
<input id="b" type="button" disabled="true" value="Take Picture"></input>
<canvas id="c" style="display:none;" width="300" height="300"></canvas>
</body>
<script>
navigator.getUserMedia({video: true}, function(stream) {
var video = document.getElementById("v");
var canvas = document.getElementById("c");
@anantn
anantn / firebase_player_assignment.js
Last active January 14, 2023 01:51
Firebase: Assigning players in a multiplayer game. This snippet assigns you a spot in a game if the game isn't full yet.
function go() {
var userId = prompt('Username?', 'Guest');
// Consider adding '/<unique id>' if you have multiple games.
var gameRef = new Firebase(GAME_LOCATION);
assignPlayerNumberAndPlayGame(userId, gameRef);
};
// The maximum number of players. If there are already
// NUM_PLAYERS assigned, users won't be able to join the game.
var NUM_PLAYERS = 4;
@anantn
anantn / firebase_create.js
Last active November 20, 2023 23:17
Firebase: Creating data if it doesn't exist. This snippet creates a user only if it doesn't already exist.
function go() {
var userId = prompt('Username?', 'Guest');
var userData = { name: userId };
tryCreateUser(userId, userData);
}
var USERS_LOCATION = 'https://SampleChat.firebaseIO-demo.com/users';
function userCreated(userId, success) {
if (!success) {
@anantn
anantn / firebase_detect_data.js
Created December 18, 2012 00:54
Firebase: Detecting if data exists. This snippet detects if a user ID is already taken
function go() {
var userId = prompt('Username?', 'Guest');
checkIfUserExists(userId);
}
var USERS_LOCATION = 'https://SampleChat.firebaseIO-demo.com/users';
function userExistsCallback(userId, exists) {
if (exists) {
alert('user ' + userId + ' exists!');