Develop Reference

Array are adding only in 0th index

I am writing a function in which i need to add the elements into an array.I am getting the data from my database.When add the element into it all the elements are only being added to the Array[0] of the rowData.
private createRowData() {
var rowData:any[] = [];
this.wakanda.catalog.then(ds => {
ds.Group.query({select : 'groupName'}).then(op => {
for(let entity of op['entities']){
rowData.push(
{row : entity.groupName});
}
});
});
return rowData;
}
My output is like this
I need something like this
How do i solve it
Thanks in advance

In the above function you are using DB call which is async and then you are sending the response without waiting for the result.
So, In this case, you will get the rowData.length 0.
send the result after the callback response.
try this:
private createRowData() {
return new Promise((resolve, reject) => {
var rowData: any[] = [];
this.wakanda.catalog.then(ds => {
ds.Group.query({ select: 'groupName' }).then(op => {
for (let entity of op['entities']) {
rowData.push({ row: entity.groupName });
}
resolve(rowData); // Send result from here
});
}).catch(reject);
})
}

Javascript function to return Elasticsearch results

I'm trying to write a JavaScript function that returns results of an Elasticsearch v5 query. I can't figure out where and how to include 'return' in this code. With the following, segmentSearch(id) returns a Promise object,{_45: 0, _81: 0, _65: null, _54: null}.
_65 holds an array of the correct hits, but I can't figure out how to parse it. The console.log(hits) produces that same array, but how can I return it from the function?
var elasticsearch = require('elasticsearch');
var client = new elasticsearch.Client({
host: 'localhost:9200',
log: 'trace'
});
segmentSearch = function(id){
var searchParams = {
index: 'myIndex',
type: 'segment',
body: {
query: {
nested : {
path : "properties",
query : {
match : {"properties.source" : id }
},
inner_hits : {}
}
}
}
}
return client.search(searchParams).then(function (resp) {
var hits = resp.hits.hits;
console.log('hits: ',hits)
return hits;
}, function (err) {
console.trace(err.message);
});
}

I would instanitate a new array outside of your client.search function in global scope and array.push your 'hits' Then access your newly filled array.
let newArr = [];
client.search(searchParams).then(function (resp) {
for(let i = 0; i < resp.hits.hits.length; i++){
newArr.push(resp.hits.hits[i]);
}
console.log('hits: ',newArr)
return newArr;
}, function (err) {
console.trace(err.message);
});

First of all, elasticsearch js client is working with Promise ( I think using callback is also possible).
Using Promise is a good way to handle asynchronous computation.
In your question, you have already done something with a promise:
var search = function(id)
{
var searchParams = { /** What your search is **/}
return client.search(searchParams)
}
This call is returning a Promise.
If we consider handleResponse as the function in your then
var handleResponse = function(resp)
{
var hits = resp.hits.hits;
console.log('hits: ',hits)
return hits; //You could send back result here if using node
}
In your code, handleResponse is called once the promise is fullfield. And in that code you are processing data. Don't forget you are in asynchronious, you need to keep working with promise to handle hits.
By the way, in your question, what you have done by using "then" is chaining Promise. It is normal to have Promise.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/then
Promise.prototype.then is returning a Promise.
var segmentSearch = function ( id )
{
return search
.then( handleResponse //here you got your hit )
.then( function ( hits )
{
console.log(hits) //and here you have done something with hits from search.
})
}

I neglected to post my fix, sorry about that. The sequence is to create searchParams, perform client.search(searchParams) which returns a Promise of hits, then process those hits:
segmentSearch = function(obj){
// retrieve all segments associated with a place,
// populate results <div>
let html = ''
var plKeys = Object.keys(obj)
var relevantProjects = []
for(let i = 0; i < plKeys.length; i++){
relevantProjects.push(obj[plKeys[i]][0])
var searchParams = {
index: 'myIndex',
type: 'segment',
body: {
query: {
nested : {
path : "properties",
query : {
match : {"properties.source" : id }
},
inner_hits : {}
}
}
}
}
client.search(searchParams).then(function (resp) {
return Promise.all(resp.hits.hits)
}).then(function(hitsArray){
...write html to a <div> using hits results
}
}

Return promises in order

I'm facing an issue to return promises using $q#all method.
I want to make promises dependent on each other, i.e.:
If I set obj1, obj2 and obj3 I want to get them in the same order.
How can I achieve this?
Factory:
mainFactory.$inject = ['$http', '$q'];
function mainFactory($http, $q) {
var mainFactory = {
getPromises: getPromises
};
return mainFactory;
function getPromises(id) {
promises = {
'obj1': $http.get('http1'),
'obj2': $http.get('http2'),
'obj3': $http.get('http3'),
'obj4': $http.get('http4', { params: { 'id': id } }),
'obj5': $http.get('http5'),
'obj6': $http.get('http6', { params: { 'id': id } })
};
return $q.all(promises);
}
}
Controller:
MainCtrl.$inject = ['mainFactory'];
function MainCtrl(mainFactory) {
var vm = this;
mainFactory.getPromises(id)
.then(getResponse)
.catch(getError);
function getResponse(response) {
var keys = Object.keys(response), i = keys.length;
while (i--) {
var key = keys[i];
console.log(key); // I want all the keys in order, i.e. => obj1, obj2.. and so on
var value = response[key].data;
switch(key) {
...
}
}
}
function getError(error) {
console.log(error);
}
}
EDIT:
I tried this way also:
var promises = {};
return $http.get('/admin/http1.json').then(function (value) {
promises['obj1'] = value;
})
.then(function (result) {
return $http.get('/admin/http2.json').then(function (value) {
promises['obj2'] = value;
});
}).then(function (result) {
return $http.get('/admin/http3.json').then(function (value) {
promises['obj3'] = value;
});
});
return $q.all(promises);

Using $q.all will resolve each promise in no particular order. If you want them to execute after each promise has been resolve, use promise chaining.
function getPromises(id) {
var getObjA = function () {
return $http.get('http1');
};
var getObjB = function () {
return $http.get('http2');
};
var getObjC = function () {
return $http.get('http3');
};
var getObjD = function () {
return $http.get('http4', { params: { 'id': id } });
};
var getObjE = function () {
return $http.get('http5');
};
var getObjF = function () {
return $http.get('http5', { params: { 'id': id } });
};
return getObjA()
.then(getObjB)
.then(getObjC)
.then(getObjD)
.then(getObjE)
.then(getObjF);
}
Edit: as an additional info, you can catch any error in any of those promise by placing a catch statement here
getPromises("id")
.then(<success callback here>)
.catch(<error callback that will catch error on any of the promises>);
Meaning, once a promise fails, all the succeeding promises below wouldn't be executed and will be caught by your catch statement

Edit 2
Mistake, I just copied you code above without realizing it was an object. LOL.
promises = [
$http.get('http1'),
$http.get('http2'),
$http.get('http3'),
$http.get('http4', { params: { 'id': id } }),
$http.get('http5'),
$http.get('http6', { params: { 'id': id } })
]
Edit 1
Sorry I didn't notice the comments Jared Smith is correct.
Object keys are inherently unordered. Use an array instead.
Edit 0
Object keys wont be ordered. Use array on declaring your promises.
promises = [
$http.get('http1'),
$http.get('http2'),
$http.get('http3'),
$http.get('http4', { params: { 'id': id } }),
$http.get('http5'),
$http.get('http6', { params: { 'id': id } })
]
$q.all(promises)
.then(functions(resolves){
// resolves here is an array
}).catch(function(err){
// throw err
});

Executing a function in a loop in javascript asynchronously- where to place defer.resolve?

I come from java/python background and new to javascript. I need to create a product list with the description of its children as well included in a jsonarray.
parent_list:
[{ children: [ 100714813, 100712694 ],
sp: '89.10',
weight: '1 ltr',
pack_type: 'Carton',
brand: 'Real',
p_desc: 'Fruit Power Juice - Orange' }]
Now for every parent I need to again iteratively fetch the children details by connecting to the database and finally have the result consolidated in a single jsonarray. But when I execute the below code, the control doesn't wait for fetching the children data( which makes sense as its being called asynchronously!), the result I get is a jsonarray that contains data only for the parents that have no children.
exports.productDetailsQuery = function(options) {
var AEROSPIKE_NAMESPACE = '';
var AEROSPIKE_SET = 'products';
var PD_KEY_VERSION_NUMBER = '1';
var defer = sails.Q.defer();
var results = options.results;
var parent_list = [];
var finalData = [];
var productKeys = results.map(
function(x){
return {
ns: AEROSPIKE_NAMESPACE,
set: AEROSPIKE_SET,
key: "pd.v" + PD_KEY_VERSION_NUMBER + '.' + 'c' + options.city_id + '.' + x.sku.toString()
}
}
);
var status = require('aerospike').status;
var breakException = {};
// Read the batch of products.
sails.aerospike.batchGet(productKeys, function (err, results) {
if (err.code === status.AEROSPIKE_OK) {
for (var i = 0; i < results.length; i++) {
switch (results[i].status) {
case status.AEROSPIKE_OK:
parent_list.push(results[i].record);
break;
case status.AEROSPIKE_ERR_RECORD_NOT_FOUND:
console.log("NOT_FOUND - ", results[i].keys);
break;
default:
console.log("ERR - %d - ", results[i].status, results[i].keys);
}
}
parent_list.forEach(function(parent){
var children = parent['children'];
console.log(children)
if(children){
var childKeys = children.map(function(child){
return {
ns: AEROSPIKE_NAMESPACE,
set: AEROSPIKE_SET,
key: "pd.v" + PD_KEY_VERSION_NUMBER + '.' + 'c' + options.city_id + '.' + child.toString()
}
});
sails.aerospike.batchGet(childKeys, function(err, childData){
if(err.code === status.AEROSPIKE_OK){
console.log('this called')
var entry = {};
entry['primary_prod'] = parent;
entry['variants'] = childData;
finalData.push(entry);
}
});
}
else{
var entry = {};
entry['primary_prod'] = parent;
finalData.push(entry);
}
});
defer.resolve(finalData);
} else {
defer.reject(err);
}
});
return defer.promise;
}
I need finalData to be like:
[{"primary_prod":{ children: [ 100714813, 100712694 ],
sp: '89.10',
weight: '1 ltr',
pack_type: 'Carton',
brand: 'Real',
p_desc: 'Fruit Power Juice - Orange' },
"variants":[{child_data},{child_data}]}, ...........]
Would really appreciate any help as to how to make it work.Is there a specific pattern to handle such cases?
Thanks!

What you have written is along the right lines but only the outer batchGet() is promisified. Because there's no attempt to promisify the inner batchGet(), it doesn't contribute to the finally returned promise.
Your overall pattern might be something like this ...
exports.productDetailsQuery = function(options) {
return sails.aerospike.batchGetAsync(...).then(results) {
var promises = results.filter(function(res) {
// Filter out any results that are not `AEROSPIKE_OK`
...
}).map(function(parent) {
// Map the filtered results to an array of promises
return sails.aerospike.batchGetAsync(...).then(function(childData) {
...
});
});
// Aggregate the array of promises into a single promise that will resolve when all the individual promises resolve, or will reject if any one of the individual promises rejects.
return sails.Q.all(promises);
});
}
... where batchGetAsync() is a promisified version of batchGet().
The fully fleshed-out the code will be longer but can be kept reasonably concise, and readable, by first defining a couple of utility functions. You might end up with something like this :
// utility function for making a "key" object
function makeKey(obj) {
return {
ns: '', //AEROSPIKE_NAMESPACE
set: 'products', //AEROSPIKE_SET
key: 'pd.v1.c' + options.city_id + '.' + obj.toString()
}
}
// promisified version of batchGet()
function batchGetAsync(obj) {
var defer = sails.Q.defer();
batchGet(obj, function(err, results) {
if(err.code === status.AEROSPIKE_OK) {
defer.resolve(results);
} else {
defer.reject(err);
}
});
return defer.promise;
}
var status = require('aerospike').status;
// Main routine
exports.productDetailsQuery = function(options) {
return batchGetAsync(options.results.map(makeKey)).then(results) {
var promises = results.filter(function(res) {
if (res.status === status.AEROSPIKE_OK) {
return true;
} else if(status.AEROSPIKE_ERR_RECORD_NOT_FOUND) {
console.log("NOT_FOUND - ", res.keys);
} else {
console.log("ERR - %d - ", res.status, res.keys);
}
return false;
}).map(function(parent) {
var entry = { 'primary_prod': parent },
children = parent['children'];
if(children) {
return batchGetAsync(children.map(makeKey)).then(function(childData) {
entry.variants = childData;
return entry;
});
} else {
return entry;
}
});
return sails.Q.all(promises);
});
}

With the new ES6 plus async stuff and babel its simpler. You can npm i -g babel npm i babel-runtime then compile and run the following with babel test.js --optional runtime --stage 2 | node:
import {inspect} from 'util';
let testData = [
{ id: 0, childIds: [1,2]},
{ id: 1, childIds:[] },
{ id: 2, childIds:[] }
];
function dbGet(ids) {
return new Promise( r=> {
r(ids.map((id) => { return testData[id];}));
});
}
async function getChildren(par) {
let children = await dbGet(par.childIds);
par.children = children;
}
async function getAll(parentIds) {
let parents = await dbGet(parentIds);
for (let p of parents) {
await getChildren(p);
}
return parents;
}
async function test() {
var results = await getAll([0]);
console.log(inspect(results,{depth:3}));
}
test().then(f=>{}).catch( e=> {console.log('e',e)});

Parse Promise and Parse Relation toghether - Javascript API

Ok guys! Could someone help me?
I have a parse DB as follow:
Person(id, name)
Product(id,serial)
Invoice(id,<Relation>products, personId)
I need to build a function that returns an array of Objects,
in each Object person.name, invoice.id,invoice.products
I'm not so good with english so I wish you understand what i mean.
so i use Parse.Promise to query the "person" and the "invoice"
function Obj(name, invoiceId, products) {
return {
name: name || '',
invoiceId: invoiceId || '',
products: products || []
};
}
function retreiveData(aName) {
var retval = [],
personQuery = new Parse.Query("Person");
personQuery.equalTo('name', aName).first().then(function(person) {
var invoiceQuery = new Parse.Query("Invoice");
return invoiceQuery.equalTo('personId', person.id).query().find();
}), then(function(invoices) {
//until here everythinks work fine
// now i've the invoices list and i have to look for related products
var promise = new Parse.Promise();
_.each(invoices, function(invoice) {
var obj = new Obj(aName, invoice.id),
promise = new Parse.Promise();
invoice.relation('products').query().find().then(function(products) {
obj.products = products;
// here i expect to have the obj fulfilled with all data
retval.push(obj);
promise.resolve();
});
return promise;
});
return promise;
});
}
var aName = 'Paul';
retreiveData(aName).then(function(retval) {
console.log('success');
/* here i have to have somethin like
retval=[{
name='paul',
invoiceId='12412412',
products=[{prod1},{prod2},{prod3}]
},{
name='paul',
invoiceId='67413412',
products=[{prod5},{prod10},{prod33}]
}]
*/
});
any idea?
i know the inner promise is wrong, but i don't understand how to fix
Thanks guyz!