| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <style> | |
| /* How to select a range of children | |
| * (Here, 3rd-7th children, inclusive): | |
| */ | |
| ul li:nth-child(n+3):nth-child(-n+7) { | |
| outline: 1px solid #0f0; | |
| } |
| 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!'); |
| 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) { |
| // assumes you add a timestamp field to each record (see Firebase.ServerValue.TIMESTAMP) | |
| // pros: fast and done server-side (less bandwidth, faster response), simple | |
| // cons: a few bytes on each record for the timestamp | |
| var ref = new Firebase(...); | |
| ref.orderByChild('timestamp').startAt(Date.now()).on('child_added', function(snapshot) { | |
| console.log('new record', snap.key()); | |
| }); |
| function extend(base) { | |
| var parts = Array.prototype.slice.call(arguments, 1); | |
| parts.forEach(function (p) { | |
| if (p && typeof (p) === 'object') { | |
| for (var k in p) { | |
| if (p.hasOwnProperty(k)) { | |
| base[k] = p[k]; | |
| } | |
| } | |
| } |
#Hello!
##I wanted to throw out an example of using Ember, Ember CLI, Emberfire, Firebase, Firebase Simple Login to set up authenticiation, and redirecting.
A couple of setup tasks:
| /** | |
| * Fancy ID generator that creates 20-character string identifiers with the following properties: | |
| * | |
| * 1. They're based on timestamp so that they sort *after* any existing ids. | |
| * 2. They contain 72-bits of random data after the timestamp so that IDs won't collide with other clients' IDs. | |
| * 3. They sort *lexicographically* (so the timestamp is converted to characters that will sort properly). | |
| * 4. They're monotonically increasing. Even if you generate more than one in the same timestamp, the | |
| * latter ones will sort after the former ones. We do this by using the previous random bits | |
| * but "incrementing" them by 1 (only in the case of a timestamp collision). | |
| */ |
| function* zip(...iterables) { | |
| let iterators = iterables.map(i => i[Symbol.iterator]()); | |
| while (true) { | |
| let entries = iterators.map(i => i.next()); | |
| let done = entries.some(entry => entry.done); | |
| if (done) break; | |
| yield entries.map(e => e.value); | |
| } | |
| } |
By: @BTroncone
Also check out my lesson @ngrx/store in 10 minutes on egghead.io!
Update: Non-middleware examples have been updated to ngrx/store v2. More coming soon!
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