Develop Reference

How to replicate data with filter in CouchDB using nano library

I have a problem in replication with filter. Everything works ok, but when i would like to change the category name which pass the filter in source db, the same record in target database still exists, but it doesn't pass the filter now, so the record in the target database should be deleted. How can i solve this problem? There is my replication function. :
nano.db.replicate('db1', 'db2',
{ create_target:true, continuous: true, filter: 'DESIGNDOCUMENT/CATEGORY' }).then((body) => {
console.log(body);
});
And below is my replication filter:
{
"_id": "_design/DESIGNDOCUMENT",
"_rev": "2-4c0bde4916dcaf68c58d904792f191f0",
"filters": {
"CATEGORY": "function(doc, req) { if (doc.category === 'category1' ) { return true; } return false; }"
}
}

Update method returns weird data, not updated data

I have a problem with update method which returns this object when I run my endpoint
{ n: 1, nModified: 1, ok: 1 }
This is the code which I tried, and I tried with { new: true } but that doesnt help, i want to get updated data back.
router.put('/:username/experience/edit/:id', function(req, res) {
const { title, company, location, from, to, workingNow, description } = req.body;
User
.update({'experience._id': req.params.id},
{'$set': {
'experience.$.title': title,
'experience.$.company': company,
'experience.$.location': location,
'experience.$.from': from,
'experience.$.to': to,
'experience.$.workingNow': workingNow,
'experience.$.description': description,
}},
function(err, model) {
console.log(model);
if(err){
return res.send(err);
}
return res.json(model);
});
})

If you are on MongoDB 3.0 or newer, you need to use the .findOneAndUpdate() and use projection option to specify the subset of fields to return. You also need to set returnNewDocument to true. Of course you need to use the $elemMatch projection operator here because you cannot use a positional projection and return the new document.
As someone pointed out:
You should be using .findOneAndUpdate() because .findAndModify() is highlighed as deprecated in every official language driver. The other thing is that the syntax and options are pretty consistent across drivers for .findOneAndUpdate(). With .findAndModify(), most drivers don't use the same single object with "query/update/fields" keys. So it's a bit less confusing when someone applies to another language to be consistent. Standardized API changes for .findOneAndUpdate() actually correspond to server release 3.x rather than 3.2.x. The full distinction being that the shell methods actually lagged behind the other drivers ( for once ! ) in implementing the method. So most drivers actually had a major release bump corresponding with the 3.x release with such changes.
db.collection.findOneAndUpdate(
{
"_id": ObjectId("56d6a7292c06e85687f44541"),
"rankings._id" : ObjectId("46d6a7292c06e85687f55543")
},
{ $inc : { "rankings.$.score" : 1 } },
{
"projection": {
"rankings": {
"$elemMatch": { "_id" : ObjectId("46d6a7292c06e85687f55543") }
}
},
"returnNewDocument": true
}
)
From MongoDB 3.0 onwards, you need to use findAndModify and the fields options also you need to set new to true in other to return the new value.
db.collection.findAndModify({
query: {
"_id": ObjectId("56d6a7292c06e85687f44541"),
"rankings._id" : ObjectId("46d6a7292c06e85687f55543")
},
update: { $inc : { "rankings.$.score" : 1 } },
new: true,
fields: {
"rankings": {
"$elemMatch": { "_id" : ObjectId("46d6a7292c06e85687f55543") }
}
}
})
Both queries yield:
{
"_id" : ObjectId("56d6a7292c06e85687f44541"),
"rankings" : [
{
"_id" : ObjectId("46d6a7292c06e85687f55543"),
"name" : "Ranking 2",
"score" : 11
}
]
}

Select2 - Pass back additional data via ajax call

Ok, I feel like I'm going crazy here. I'm using the select2 jquery plugin (version 4), and retrieving data via ajax. So you can type in a name, and it will return that contact information. But I also want to return what organization that contact is a part of.
Here is my select2 initialization:
$('#contact_id').select2({
ajax: {
url: 'example.com/contacts/select',
dataType: 'json',
delay: 250,
data: function (params) {
return {
q: params.term,
page: params.page
};
},
processResults: function (data) {
return {
results: data
};
},
cache: true
},
minimumInputLength: 3,
maximumSelectionLength: 1
});
And here is the data I'm returning (laravel framework):
foreach($contacts as $con) {
$results[] = [
'id' => $con->contact_id,
'text' => $con->full_name,
'org' => [
'org_id' => $con->organization_id,
'org_name' => $con->org_name
]
];
}
return response()->json($results);
So isn't 'org' supposed to be attached to either the created option or select element by select2? So I could do something like $('#contact_id').select2().find(':selected').data('data').org or $('#contact_id').select2().data('data').org or something like that?
Idealistically, this would look like:
<select>
<option value="43" data-org="{org_id:377, org_name:'Galactic Empire'}">Darth Vader</option>
</select>
I swear I confirmed this worked last week, but now it's completely ignoring that org property. I have confirmed that the json data being returned does include org with the proper org_id and org_name. I haven't been able to dig anything up online, only this snippet of documentation:
The id and text properties are required on each object, and these are the properties that Select2 uses for the internal data objects. Any additional paramters passed in with data objects will be included on the data objects that Select2 exposes.
So can anyone help me with this? I've already wasted a couple hours on this.
EDIT: Since I haven't gotten any responses, my current plan is to use the processResults callback to spawn hidden input fields or JSON blocks that I will reference later in my code. I feel like this is a hacky solution given the situation, but if there's no other way, that's what I'll do. I'd rather that than do another ajax call to get the organization. When I get around to implementing it, I'll post my solution.

Can't comment for now (low reputation).. so... answering to slick:
Including additional data (v4.0):
processResults: function (data) {
data = data.map(function (item) {
return {
id: item.id_field,
text: item.text_field,
otherfield: item.otherfield
};
});
return { results: data };
}
Reading the data:
var data=$('#contact_id').select2('data')[0];
console.log(data.otherfield);

Can't remember what I was doing wrong, but with processResults(data), data contains the full response. In my implementation below, I access this info when an item is selected:
$('#select2-box').select2({
placeholder: 'Search Existing Contacts',
ajax: {
url: '/contacts/typeahead',
dataType: 'json',
delay: 250,
data: function(params){
return {
q: params.term,
type: '',
suggestions: 1
};
},
processResults: function(data, params){
//Send the data back
return {
results: data
};
}
},
minimumInputLength: 2
}).on('select2:select', function(event) {
// This is how I got ahold of the data
var contact = event.params.data;
// contact.suggestions ...
// contact.organization_id ...
});
// Data I was returning
[
{
"id":36167, // ID USED IN SELECT2
"avatar":null,
"organization_id":28037,
"text":"John Cena - WWE", // TEXT SHOWN IN SELECT2
"suggestions":[
{
"id":28037,
"text":"WWE",
"avatar":null
},
{
"id":21509,
"text":"Kurt Angle",
"avatar":null
},
{
"id":126,
"text":"Mark Calaway",
"avatar":null
},
{
"id":129,
"text":"Ricky Steamboat",
"avatar":null
},
{
"id":131,
"text":"Brock Lesnar",
"avatar":null
}
]
}
]

Firebase: How do I retrieve records from my data for which a specific key exists?

I have data in firebase that looks like this:
"application": {
"companies": {
"firebase": {
"creation": {
"name": "Firebase Inc",
"location": "USA"
},
"google": {
"creattion": {
"name": "Google Inc",
"location": "USA"
}
}
"facebook": {
},
"apple": {
}
}
}
}
There are tens of thousands of records under companies key. How do i efficiently execute following queries?
How do I query only the records for which key creation is present under their name?
How do I query only the records that DO NOT have key creation present under their name?
I also want to call .on('child_added') on the returned result set so that I can process only those specific records later on. Is it possible?

EDIT: Simpler way without using an extra parameter
Queries
Here are the queries to do this without having to use an extra parameter:
Find the companies without creation:
var ref = new Firebase(fbUrl+'/companies').orderByChild("creation").equalTo(null);
Find the companies with creation:
var ref = new Firebase(fbUrl+'/companies').orderByChild("creation").startAt(!null);
You would add ".indexOn": "creation" to the rules.
Edit 2: I was curious, so I pushed 11,000 records to /companies2 (half with creation children, half without). I was able to retrieve 5500 matching records in ~4 seconds using the above queries (or one of the variants I've shown below).
Edit 3: If you're running these queries frequently, it might be worth it to separate children of /companies into two bins based the presence of creation. That way, you can read the two segments separately without having to rely on queries.
Factory
Here is what the revised factory would look like (I've revised the PLNKR to match):
app.factory("CompaniesFactory",function($q, fbUrl){
return function(hasCreation){
var deferred = $q.defer();
var ref = new Firebase(fbUrl+'/companies').orderByChild("creation");
var query;
if (hasCreation) {
query = ref.startAt(!null);
// or:
// query = ref.startAt(true);
} else {
query = ref.equalTo(null);
// or:
// query = ref.endAt(!null);
// query = ref.endAt(true);
}
query.once("value", function(dataSnapshot){
deferred.resolve(dataSnapshot.val());
}, function (error) {
deferred.reject(error);
});
return deferred.promise;
}
});
And yes, it is possible to call .on('child_added') on the returned dataSnapshot. See DataSnapshot.ref().
Original answer using an extra parameter:
(Keeping this for reference)
Another way to do it would be by adding another parameter called hasCreation to children of companies that have creation, and query by that.
Data
The query would then be var ref = new Firebase(fbUrl+'/companies').orderByChild("hasCreation").equalTo(hasCreation);
If hasCreation in the query is null, the query will return the companies without a hasCreation child.
If hasCreation in the query is true, the query will return the companies with hasCreation===true.
{
"company1" : {
"creation" : {
"name" : "company1"
},
"hasCreation" : true
},
"company2" : {
"name" : "company2"
},
"company3" : {
"name" : "company3"
},
"company4" : {
"creation" : {
"name" : "company4"
},
"hasCreation" : true
}
}
Rules
You would add the ".indexOn" : "hasCreation" to your rules like so:
"so:29179389":{
".read" : true,
".write" : true,
"companies" : {
".indexOn" : "hasCreation"
}
}
Companies Factory
app.factory("CompaniesFactory",function($q, fbUrl){
return function(hasCreation){
var deferred = $q.defer();
if (!hasCreation) {
hasCreation = null;
}
var ref = new Firebase(fbUrl+'/companies').orderByChild("hasCreation").equalTo(hasCreation);
ref.once("value", function(dataSnapshot){
deferred.resolve(dataSnapshot.val());
});
return deferred.promise;
}
});
Controller
app.controller('HomeController',function($scope,fbUrl,CompaniesFactory) {
$scope.getCompanies = function(hasCreation) {
var companies = new CompaniesFactory(hasCreation).then(function(data){
console.log(data);
$scope.companies = data;
});
}
});
HTML
<body ng-app="sampleApp">
<div ng-controller="HomeController">
<button ng-click="getCompanies(true)">Find with creation</button>
<button ng-click="getCompanies(false)">Find without creation</button>
<h2>Companies:</h2>
{{companies}}
</div>
</body>

What I would do, is I would set a condition to verify if your xxx.firebaseio.com/Application/companies/______/creation exists. In a empty blank, you can set for loop to irritate over the array of companies.Then, you can create two arrays with angular.forEach: one including those companies which do have 'creation', and the other array in which the elements do not include the 'creation'.
Hope that helps :)
Edit:
There is another approach to this question, in this thread:
Angularfire: how to query the values of a specific key in an array?

Select2 load JSON resultset via AJAX and search locally

Until now I've been using Select2's normal AJAX method of searching and filtering data serverside, but now I have a usecase where I want to retrieve all the results via AJAX when the select is opened and then use those results (now stored locally) to search and filter.
I've trawled the web looking for examples of how to do this and all i've found is lots of people saying the Query method should be used rather than the AJAX helper. Unfortunately I haven't found any examples.
So far all I've managed is the basic:
$('#parent').select2({
placeholder: "Select Parent",
minimumInputLength: 0,
allowClear: true,
query: function (query) {
//console.log(query);
query.callback(data);
}
});
data = {
more: false,
results: [
{ id: "CA", text: "California" },
{ id: "AL", text: "Alabama" }
]
}
Data is being passed to the select but query filtering is not implemented.
I'm struggling to understand the select2 documentation and would appreciate any assistance or links to examples.

Try the following - pre-load json data into local variable and when ready bind this to select2 object
<script>
function format(item) { return item.text; }
var jresults;
$(document).ready(function() {
$.getJSON("http://yoururl.com/api/select_something.json").done(
function( data ) {
$.jresults = data;
$("#parent").select2(
{formatResult: format,
formatSelection: format,
data: $.jresults }
);
}
)
});
</script>