topic Re: Hypercube callback after every selection in Integration, Extension & APIs

Hypercube callback after every selection

thpessato — Wed, 01 Nov 2017 16:21:53 GMT

Hello all,

I'm creating a mashup using hypercube.

I'm trying to use a hypercube to get value 'Year', from a expression using the Qlik Engine. After that, I want to make an automatic selection on the field 'Year'.

So ok, my hypercube is working and calling my callback function. Then I set my selection on the right field. And it works.

But I realized that the callback function keeps getting called after every selection made on the mashup. Since my data doesn't change, I don't want it to happen. It's unecessary.

I managed this issue by:

1. Placing a flag like:

var hypercubeDone = false;

function callback(reply, app) {

if(hypercube) {

return;

}

// do some stuff

hypercubeDone = true;
}

in my JavaScript file.

But that doesn't solve my problem of calling this method multiple times. So I tried another solution...

2. Destroying the hypercube after the call:

But don't know if this is a good practice. So I tried to find another way.

I don't want this to happen, since it is not necessary. Is there a right way to prevent this?

Thanks!!

Re: Hypercube callback after every selection

ErikWetterberg — Wed, 01 Nov 2017 16:34:30 GMT

Hi,

You could use evaluate Evaluate method ‒ Qlik Sense instead.

Erik Wetterberg

Re: Hypercube callback after every selection

thpessato — Tue, 07 Nov 2017 15:33:31 GMT

Using hypercube, I can get a different callback for each expression, but with 'Evaluate' I can't, since it's a WebSocket and the only event I get from sending a request is

ws.onmessage = function(){};

Ideal would be if there's something like

ws.send(JSON.stringify(expressionData), function(response){
console.log("hey, this is the response: ", response);
});

Should a lot of ifs or switch/case inside onmessage = "" or there is another way to do this?

Thanks!

Re: Hypercube callback after every selection

ErikWetterberg — Tue, 07 Nov 2017 16:06:49 GMT

Hi,

You should get hold of the enigmaModel, which has an evaluate method defined that returns a promise. Basically enigmajs wraps all QIX methods this way, and so solves the problem of connecting request and response for you.

In an extension it would be something like:

model.enigmaModel.app.evaluate('1+1').then(function(reply){

console.log(reply);

})

Haven't tried in a mashup, but something like:

app.enigmaModel.evaluate('1+1').then(function(reply){

console.log(reply);

})

You might need to use the console to find the object that has the evaluate method defined.

Hope this helps

Erik Wetterberg

Re: Hypercube callback after every selection

thpessato — Tue, 07 Nov 2017 16:30:10 GMT

Hey there!

This sounds really good and straightforward to make some generic functions across a mashup. I'll look deep into it and post here if solves my issue, with my code as well

Thanks Erik!

Re: Hypercube callback after every selection

ErikWetterberg — Wed, 08 Nov 2017 12:54:14 GMT

Checked this up: if you use qlik.js (AKA capability api's, mashup API) to open the app, you will find the enigmaModel at app.model.enigmaModel.

So the call will be:

app.model.enigmaModel.evaluate('1+1').then(function(reply){

console.log("evaluated:",reply);

});

Hope this helps

Erik Wetterberg

Re: Hypercube callback after every selection

thpessato — Fri, 10 Nov 2017 12:47:26 GMT

This is just great for front end development. Thanks for the tip!

Re: Hypercube callback after every selection

Francis_Kabinoff — Fri, 10 Nov 2017 14:10:59 GMT

Just use the promise instead of the callback.

app.createCube({

// stuff

}, function(layout) { //this is the callback, just dont use it })

instead do this

app.createCube({

// stuff

}).then(function(object) { // here you'll get the object, which has layout on it, and this will only run once })

Re: Hypercube callback after every selection

paulcalvet — Thu, 07 Dec 2017 16:18:33 GMT

Hi Francis,

How can I retrieve the value of the expression in the promise ?

What code should I write ?

When I look at the "object" in the chrome debug, I don't find the value of the expression.

app.createCube({

"qInitialDataFetch": [

{

"qHeight": 20,

"qWidth": 1

}

"qDimensions": [],

"qMeasures": [

{

"qDef": {

"qDef": "max({$<[Year Month]={$(=maxstring([Year Month]))}>}Month)"

"qLabel": "GetPlatform",

"qLibraryId": null,

"qSortBy": {

"qSortByState": 0,

"qSortByFrequency": 0,

"qSortByNumeric": 0,

"qSortByAscii": 1,

"qSortByLoadOrder": 0,

"qSortByExpression": 0,

"qExpression": {

"qv": " "

}

"qSuppressZero": false,

"qSuppressMissing": false,

"qMode": "S",

"qInterColumnSortOrder": [],

"qStateName": "$"

}).then(function(object) {

// here you'll get the object, which has layout on it, and this will only run once

What shoul I do write here ?

});

Thanks !

Paul

Re: Hypercube callback after every selection

ErikWetterberg — Fri, 08 Dec 2017 06:05:35 GMT

Hi Paul,

Don't use a Hypoercube if you only want one expression evaluated, use a ValueExpression instead. Also note that createCube will create a subscription, so the expression will be recalculated when there are changes in selection state that affects the result. By using the promise instead of the callback you will not be notified, by the calculation will be made anyhow. Evaluate is really better for a one-time calculation.

Hope this helps

Erik Wetterberg

Re: Hypercube callback after every selection

paulcalvet — Fri, 08 Dec 2017 08:58:19 GMT

Thanks Erik,

I want to select the last month available when the user open the mashup.

I use the app.field function to do this :

app.field('Month').selectValues([11], false, true);

I try with this code, but it doesn't work...

app.createGenericObject( {

fields: {

qValueExpression:{"qExpr":"=max({$<[Year Month]={$(=maxstring([Year Month]))}>}Month)"}

}

}).then (function ( object ) {

var str = object.fields;

app.field('Month').selectValues([str], false, true);

console.log(str);

});

Thanks,

Paul

Re: Hypercube callback after every selection

ErikWetterberg — Fri, 08 Dec 2017 09:06:32 GMT

Hi,

Try this:

app.model.enigmaModel.evaluate('max({$<[Year Month]={$(=maxstring([Year Month]))}>}Month)').then(function(reply){
     console.log("evaluated:",reply);
app.field('Month').selectValues([str], false, true);
});

Hope this helps

Erik Wetterberg

Re: Hypercube callback after every selection

ErikWetterberg — Fri, 08 Dec 2017 09:09:57 GMT

Sorry, pretty difficult to edit those javascript snippet: it should of course say reply, not str in line 3. You also might need to convert string to number, not sure if the reply will be a string or number.

Hope this helps

Erik Wetterberg

Re: Hypercube callback after every selection

paulcalvet — Fri, 08 Dec 2017 09:22:13 GMT

Ok, if I want to use app.model.enigmaModel.evaluate I need to load enigma.js before.

Is it possible to do this without enigma.js ?

Paul

Re: Hypercube callback after every selection

paulcalvet — Fri, 08 Dec 2017 16:19:43 GMT

Erik,

I found the solution.

The value returned by the function is in Object.layout

app.createGenericObject( {

year : {

qValueExpression: "=max({$<[Year Month]={\"$(=maxstring([Year Month]))\"}>}Year)"

month: {

qValueExpression: "=max({$<[Year Month]={\"$(=maxstring([Year Month]))\"}>}Month)"

}

}).then(function ( Object ) {

app.field('Month').selectValues([Object.layout.month], false, true);

app.field('Year').selectValues([Object.layout.year], false, true);

});

Many thanks !!

Re: Hypercube callback after every selection

Anonymous — Mon, 24 Dec 2018 12:26:59 GMT

Hi I am totally new to mashups,
I have a business requirement where i am creating mashup from two different Apps( few objects from each app on single page ) and want selection from one app to be propagated to another without any CreateList function , more like qliksense does for a single app.
Is there any way to do that ?