topic Re: Can I get values from a table via a WebSocket? in Integration, Extension & APIs

Can I get values from a table via a WebSocket?

Anonymous — Mon, 09 Apr 2018 10:50:05 GMT

I created a table in Qlik Sense with dimensions and measures. Also one measure has an expression. Why I can't see the expression on console (another fillds I can see)? How to get the content of the table using Websocket? I want to show the table using only table's ID.

//connection

var WebSocket = require('ws');

var fs = require('fs');

var certificates = {

cert: fs.readFileSync('./certificats/client.pem'),

key: fs.readFileSync('./certificats/client_key.pem'),

root: fs.readFileSync('./certificats/root.pem')

};

var ws = new WebSocket("wss://server.domen:9999/app/", {

ca: certificates.root,

cert: certificates.cert,

key: certificates.key,

headers: {

'X-Qlik-User': 'UserDirectory=internal; UserId=sa_engine'

}

});

//queries

ws.onopen = function (event) {

var OpenDoc = {

"method": "OpenDoc",

"handle": -1,

"params": [

"AppID"

"outKey": -1,

"id": 1

}

var GetObject = {

"handle": 1,

"method": "GetObject",

"params": {

"qId": "ObjectID"

"outKey": -1,

"id": 3

}

var GetLayout = {

"handle": 2,

"method": "GetLayout",

"params": {},

"outKey": -1,

"id": 4

}

ws.send(JSON.stringify(OpenDoc));

ws.onmessage = function (event) {

var response = JSON.parse(event.data);

console.log(response);

};

ws.send(JSON.stringify(GetObject));

ws.onmessage = function (event) {

var response = JSON.parse(event.data);

console.log(response);

};

setTimeout(function() { ws.send(JSON.stringify(GetFullPropertyTree));

ws.onmessage = function (event) {

var response = JSON.parse(event.data);

var dimensionInfo = response.result.qLayout.qHyperCube.qDimensionInfo;

var measureInfo = response.result.qLayout.qHyperCube.qMeasureInfo;

dimensionInfo.forEach(function(item, dimensionInfo) {

console.log(item.qFallbackTitle);

})

measureInfo.forEach(function(item, measureInfo) {

console.log(item.qFallbackTitle);

})

} }, 2000);

};

Re: Can I get values from a table via a WebSocket?

m_s — Wed, 11 Apr 2018 15:30:49 GMT

Hello Илья,

I think you made a pasting error (you create a variable called GetLayout and then later stringify a variable GetFullPropertyTree) but that shouldnt really matter.

I always use the Engine-API-Explorer for these kind of things because it is very helpful (/dev-hub/engine-api-explorer):

When looking at the result of GetFullPropertyTree we can see that there is no property named "qMeasureInfo" inside the qHyperCubeDef, only a property called "qMeasures".Inside the individual measure's objects is another property called qDef which in turn contains the expression used for this measure.

To find the correct paths / properties just play around with the engine-api-explorer. You can also check out Qliks enigma.js which should simplify the communication with qlik sense

Cheers,

Mathias

Re: Can I get values from a table via a WebSocket?

Anonymous — Wed, 18 Apr 2018 08:44:54 GMT

Thanks a lot!

Can I get field's values in this way? I can calculate measures but EvaluateEx function returns only one result. I want to calculate measures for all rows. Is it possible to get rows?

Re: Can I get values from a table via a WebSocket?

m_s — Wed, 18 Apr 2018 12:09:05 GMT

You can get values by using a hypercube (which you can construct using a HyperCubeDefinition).

For a GetObject-handle you can probably use something like this:

{

"method": "GetHyperCubeData",

"params": {

"qPath": "/qHyperCubeDef",

"qPages": [

{

"qLeft": 0,

"qTop": 0,

"qWidth": 99,

"qHeight": 99

}

]

}

Mathias

Re: Can I get values from a table via a WebSocket?

neeraj712 — Sun, 05 May 2019 18:39:35 GMT

Were you able to solve this issue ?
I am also following same approach ..connecting through websocket , used methods to OpenDoc , Doreload and then want to read field values to render chart.
If you have worked out a solution can you share next steps to followed to get values of the fields.

Thanks
NK

Re: Can I get values from a table via a WebSocket?

Øystein_Kolsrud — Mon, 06 May 2019 06:26:51 GMT

Hypercubes and list objects are the primary entities in the engine API to use for retrieving data. A good starting point to learn about this can be this section:

https://help.qlik.com/en-US/sense-developer/April2019/Subsystems/Platform/Content/Sense_PlatformOverview/Concepts/concepts.htm

In particular, I would recommend the sub pages named "GenericObject", "Hypercube", "List object" and "Paging". There are also quite a few threads here on Community on the topic, so if you search for "Hypercube" you will find a lot of discussions that might be close to what you need.

And if you're comfortable with C#, then you can find an example project that illustrates how to use hypercubes for different purposes (data retrieval, selection, sorting, etc) here: https://github.com/kolsrud/qlik-dot-net-sdk-hypercube-usage

Re: Can I get values from a table via a WebSocket?

neeraj712 — Fri, 19 Jul 2019 16:33:21 GMT

different approach here >>

Trying to read a file through a QS-extension object ,
Extension JS script can read file in case 1 but fails when we try case 2 as provided below :

Case 1:
var filenm = 'http://localhost:4848/Extensions/myChart/abc.log; // CASE 1 : SUCCESS when in QS Desktop it works
d3.tsv( filenm, function(data) {
return {
Timestamp: data.Timestamp,
ActiveUsers: data.ActiveUsers ,
Users: data.Users,
};

}, function(error, rows) {
if (error) { //if error is not null,
console.log('error: '+ error);
} else if (index < rows.length) {
yVal1=rows[index].ActiveUsers;
yVal2=rows[index].Users;
++index;
}
else {
//duration(10000);
}
});
...other steps

Case 2:

var filenm = 'C:/Log/abc.log; // CASE 2: Failed while pointing to other directory in QS dekstop

d3.tsv( filenm, function(data) {
return {
Timestamp: data.Timestamp,
ActiveUsers: data.ActiveUsers ,
Users: data.Users,
};

}, function(error, rows) {
if (error) { //if error is not null,
console.log('error: '+ error);
} else if (index < rows.length) {
yVal1=rows[index].ActiveUsers;
yVal2=rows[index].Users;
++index;
}
else {
//duration(10000);
}
});
...other steps

Do you know if /how approach 2 can work ?