Develop Reference

Optimalization of firebase query. Getting data by ids

I'm new in Firebase. I would like to create an app (using Angular and AngularFire library), which shows current price of some wares. I have list all available wares in Firebase Realtime Database in the following format:
"warehouse": {
"wares": {
"id1": {
"id": "id1",
"name": "name1",
"price": "0.99"
},
"id2": {
"id": "id2",
"name": "name2",
"price": "15.00"
},
... //much more stuff
}
}
I'm using ngrx with my app, so I think that I can load all wares to store as an object not list because normalizing state tree. I wanted load wares to store in this way:
this.db.object('warehouse/wares').valueChanges();
The problem is wares' price will be refresh every 5 minutes. The number og wares is huge (about 3000 items) so one response will be weight about 700kB. I know that I will exceed limit downloaded data in a short time, in this way.
I want limit the loading data to interesing for user, so every user will can choose wares. I will store this choices in following way:
"users": {
"user1": {
"id": "user1",
"wares": {
"id1": {
"order": 1
},
"id27": {
"order": 2
},
"id533": {
"order": 3
}
},
"waresIds": ["id1", "id27", "id533"]
}
}
And my question is:
Is there a way to getting wares based on waresIds' current user? I mean, does it exist way to get only wares, whose ids are in argument array? F.e.
"wares": {
"id1": {
"id": "id1",
"name": "name1",
"price": "0.99"
},
"id27": {
"id": "id27",
"name": "name27",
"price": "0.19"
},
"id533": {
"id": "id533",
"name": "name533",
"price": "1.19"
}
}
for query like:
this.db.object('warehouse/wares').contains(["id1", "id27", "id533"]).valueChanges();
I saw query limits in Angular Fire like equalTo and etc. but every is for list. I'm totally confused. Is there anyone who can help me? Maybe I'm making mistakes in the design of the app structure. If so, I am asking for clarification.

Because you are saving the ids inside user try this way.
wares: Observable<any[]>;
//inside ngOnInit or function
this.wares = this.db.list('users/currentUserId/wares').snapshotChanges().map(changes => {
return changes.map(c => {
const id = c.payload.key; //gets ids under users/wares/ids..
let wares=[];
//now get the wares
this.db.list('warehouse/wares', ref => ref.orderByChild('id').equalTo(id)).valueChanges().subscribe(res=>{
res.forEach(data=>{
wares.push(data);
})
});
return wares;
});
});

There are two things you can do. I don't believe Firebase allows you to query for multiple equals values at once. You can however loop over the array of "ids" and query for each one directly.
I am assuming you already queried for "waresIds" and you've stored those ID's in an array named idArray:
for id in idArray {
database.ref('warehouse/wares').orderByChild('id').equalTo(id).once('value').then((snapshot) => {
console.log(snapshot.val());
})
}
In order to use the above query efficiently you'll have to index your data on id.
Your second option would be to use .childChanged to get only the updated data after your initial fetch. This should cut down drastically on the amount of data you need to download.

Yes , you can get exactly data that you want in firebase,
See official Firebase documents about filtering
You need to get each waresID
var waresID = // logic to get waresID
var userId = // logic to get userId
var ref = firebase.database().ref("wares/" + userId).child(waresID);
ref.once("value")
.then(function(snapshot) {
console.log(snapshot.val());
});
this will return only data related to that waresID or userId
Note: this is javascript code, i hope this will work for you.

Swapping data in Angular UI-Grid, new columns not visible when changing dataset externally

I've got a query tool I've been working on, which has an angular form that is filled out, and then when it's submitted it uses AJAX which returns JSON, which is then rendered into ui-grid, that JSON response looks like
{
"success": true,
"message": "",
"columns": ["first_name", "last_name", "company", "employed"]
"results": [
{first_name: "John", last_name: "Smith", company: "Abc Inc", employed: true},
{first_name: "Johnny", last_name: "Rocket", company: "Abc Inc", employed: true}]
}
I'm working on both the PHP and angular so I have full control over this JSON response if need be. I'm running into an issue when my JSON response from a first AJAX call is rendered, and then I run another, seperate AJAX call on the same page and get a new data set: this new data set does not render any of the columns that were not in the original data set. This is hugely problematic as the table is essentially cleared when none of the columns are the same, and I often need to load completely different data into ui-grid in this single page app.
When the JSON is recieved I simply bind the jsonResult.results to the old $scope.myData variable that ui-grid is bound to.
I've made a plunker isolating this issue. A dataset with a "punk" column is loaded, and then clicking "swap data" will try to load a dataset with "employee" column instead of "punk". I've so far looked into directives that will refresh or reload when the $scope.myData variable changes using $watch, and looked at finding something like $scope.columnDefs to let ui-grid know. Relatively new to angular and javascript so directives are still a bit over my head.

I have updated your plunker slightly:
$scope.swapData = function() {
if ($scope.gridOpts.data === data1) {
$scope.gridOpts.columnDefs = [
{ name:'firstName' },
{ name:'lastName' },
{ name:'company' },
{ name:'employee' }
];
$scope.gridOpts.data = data2;
//punk column changes to employee
}
else {
$scope.gridOpts.columnDefs = [
{ name:'firstName' },
{ name:'lastName' },
{ name:'company' },
{ name:'punk' }
];
$scope.gridOpts.data = data1;
//employee column changes to punk
}
};
http://plnkr.co/edit/OFt86knctJxcbtf2MwYI?p=preview
Since you have the columns in your json, it should be fairly easy to do.

One additional piece that I figured out with the help of Kevin Sage's answer and the plunker example... If you are using the backward-compatible "field" attribute the swapping does not work properly when there are field name overlaps between the two sets of column definitions. The column headers and the column widths are not rendered properly in this case. Using the "name" attribute of the column definition corrects this.
$scope.swapData = function() {
if ($scope.gridOpts.data === data1) {
$scope.gridOpts.columnDefs = [
{ field:'firstName' },
{ field:'lastName' },
{ field:'company' },
{ field:'employee' }
];
$scope.gridOpts.data = data2;
//punk column changes to employee
}
else {
$scope.gridOpts.columnDefs = [
{ field:'firstName' },
{ field:'lastName' },
{ field:'company' },
{ field:'punk' }
];
$scope.gridOpts.data = data1;
//employee column changes to punk
}
};
Example here: Plunker

My solution:
$http.get('url').success(function(res) {
// clear data
gridOptions.data.length = 0;
// update data in next digest
$timeout(function() {
gridOptions.data = res;
});
});

How to add a new object to an array nested inside an object?

I'm trying to get a handle on using $resource in angularjs and I keep referencing this answer AngularJS $resource RESTful example for good examples. Fetching a record and creating a record work fine, but now i'm trying to add a "section" to an existing mongo record but can't figure it out.
documents collection
{
_id: 'theid',
name: 'My name",
sections: [
{
title: 'First title'
},
{
title: 'Second title'
}
]
}
angular controller snippet
var document = documentService.get({_id: 'theid'});
// TRYING TO ADD $scope.section TO THE SECTIONS ARRAY IN THE VARIABLE document.
//document.sections.push($scope.section); <-- This does NOT work
//document.new_section($scope.section); <-- could do this and then parse it out and insert it in my backend code, but this solution seems hacky and terrible to me.
document.$save(function(section) {
//$scope.document.push(section);
});
documentService
return $resource(SETTINGS.base + '/documents/:id', { id: '#id' },
{
update: { method: 'PUT' }
});
From the link i posted above, If I was just updating the name field, I could just do something like this:
var document = documentService.get({_id: 'theid'});
document.name = "My new name";
document.$save(function(section) {
//$scope.document.push(section);
});
I'm just trying to add an object to a nested array of objects.

Try this:
documentService.get({_id: 'theid'}, function(document) {
document.sections.push($scope.section);
document.$save();
});

Iterate through poorly formated object

I have a really bad-formated javascript object:
commits = {
commit: {
name: 'First commit'
},
commit: {
name: 'Second commit'
}
}
As you can see, each sub-object of commits object is called commit so it practically precludes an option to use for ... in ... or any other javascript loop (well, that's what i think but i'm a really poor JS programmer so i'm probably wrong). So, the question is, how can i iterate through that object?
Please have in mind that i can't use jQuery here and i can't rewrite that object
edit: that object is parsed from the following json:
{
"commits": {
"commit": {
"name": "First commit"
},
"commit": {
"name": "Second commit"
},
}
}

Considering the JSON posted in the github link you provided, there's not a lot you have to do.
The JSON string seems to be valid, except that it's missing a } at the end of the string. With that fixed, it parses just fine:
JSON.parse('{\n \"accountURL\": \"https://domain.com\",\n \"newCommitsCount\": \"1\",\n \"pushURL\":\"https://domain.com/project/64249/git/source/compare/revisions/0b6438955f2a5a7981fd25cfa5b48fe3fb4c888d,7771e638d1356a14d1dc46f3f5cfaab858370a5e\",\n \"unsubscribeURL\": \"https://domain.com:443/unsubscribe?token=receiverToken&type=COMMITS&projectId=64249\",\n \"invokerEmail\": \"email#email.com\",\n \"projectURL\": \"https://domain.com/project/64249\",\n \"projectId\": \"64249\",\n \"afterPushRevision\": \"7771e638d1356a14d1dc46f3f5cfaab858370a5e\",\n \"invokerId\": \"38074\",\n \"pushDate\": \"2014-02-11T15:26:36+0000\",\n \"beforePushRevision\": \"0b6438955f2a5a7981fd25cfa5b48fe3fb4c888d\",\n \"repositoryURL\": \"git_url\",\n \"subdomain\": \"subdomain\",\n \"domain\": \"domain\",\n \"branch\": \"develop\",\n \"invokerProfileURL\": \"url\",\n \"commitsCount\": \"1\",\n \"invokerSmallAvatarURL\": \"xx\",\n \"projectName\": \"NAME\",\n \"invoker\": \"Invoker Name.\",\n \"commits\": {\"commit\": {\n \"revision\": \"7771e638d1356a14d1dc46f3f5cfaab858370a5e\",\n \"commitMessage\": \"quickfix\",\n \"committerId\": \"38074\",\n \"committerEmail\": \"email\",\n \"committerName\": \"Name.\",\n \"commitDate\": \"2014-02-11T15:26:27+0000\",\n \"commitURL\": \"https://domain.com/project/64249/git/source/commit/develop/7771e638d1356a14d1dc46f3f5cfaab858370a5e\" }}}')

Iteration in handlebar using backbone

I'm using backbone and handlebars for templating and i'm new to this.
My current json is in the below format and the code works fine.
[
{
"id": "10",
"info": {
"name": "data10"
}
},
{
"id": "11",
"info": {
"name": "data11"
}
}
]
But when i change my json structure to something like shown below i'm having difficulty in getting things to be populated.
{
"total_count": "10",
"dataElements": [
{
"id": "10",
"info": {
"name": "data10"
}
},
{
"id": "11",
"info": {
"name": "data11"
}
}
]
}
How can i populate name, info and total_count keeping the current code structure ?
JSFiddle : http://jsfiddle.net/KTj2K/1/
Any help really appriciated.

A few things that you need to do in order for this to work.
Replace Backbone's core 'reset' on your collection with a custom one that understands the data you are passing to it. For example:
reset: function (data) {
this.totalCount = data.total_count;
Backbone.Collection.prototype.reset.call(this, data.dataElements);
}
Now when you reset your collection, it will pull the total_count out of the object you are resetting it with, and use Backbone's core reset with the dataElement array. Keep in mind you may have to do a similar thing with 'parse' if you're intending on pulling this from the server.
I'd recommend that (if your example looks anything like the real code you're working with) you reset your collection before getting to rendering.
var dataCollectionList = new dataCollection();
dataCollectionList.reset(jsonData);
var App = new AppView({model : dataCollectionList});
Now in your view's "render" method you can grab the 'totalCount' property off the collection -
render : function() {
//Should spit the total count into the element, just as an example
this.$el.append(this.model.totalCount);
//or console.log it
console.log(this.model.totalCount);
return this;
}
Voila. Side note - as someone who works with Backbone a lot, it drives me nuts when people set an attribute of something like "model" (i.e. peopleModel, itemModel, etc) and it ends up being a backbone collection. It's much clearer to name it after what it is - though some MVC purists may disagree a bit.
Also, in this code block:
_.each(this.model.models, function (myData) {
$(this.el).append(new ItemView({model:myData}).render().el);
}, this);
You don't need to do _.each(this.model.models.......). Since you're working with a collection, the collection has a built in 'each' method.
this.model.each(function (myData) { ..... } , this);
Quite a bit cleaner.