In a mashup, detect / be notified when a visualisation has been redrawn

[Anonymous]

I'm using a mashup to automate generating images of charts - I run it inside a headless browser using Puppeteer.

I'd like to be able to generate a set of screenshots every time I change the selections: this would be much quicker than having to reload the page every time with different selections.

The problem is that there might be a small delay in refreshing the visualisations after the selections change, so I'd like to know when the refresh is complete before taking the screenshot. Is there a way to do this using an event listener?

Here is the mashup code that creates the visualizations and exposes them to the automation system:

     function showAndRegister(el, obj) {
          app.visualization.get(obj).then(function(vis) {
               vis.show(el);
               if (window.automator.onVisualization){
                    window.automator.onVisualization(el, obj);
               }                    
          });
     }
     
     window.automator.setCountry = function(code) {
          var field = app.field('Country Code');
          field.clear();
          field.selectValues([{qText: code}]);
     }
     
     //add the objects --
     showAndRegister('QV04','gzCQfU');
     showAndRegister('QV03','RwGpFhZ');
     showAndRegister('QV02','EqHaWS');
     showAndRegister('QV01','QSLrsS');

[Anonymous · Accepted solution]

For what it's worth:

// vis.show returns a promise that resolves to an object, I don't know what kind
// but whatever the object is, you can set its options.onRendered to a callback
var p = app.visualization.get(obj).then((vis) => vis.show(el, opts))

p.then((x) => x.options.onRendered = (() =>console.log('Rendered!')))

And even easier, found thanks to https://github.com/qlik-oss/qlik-sense-visualization-extension-testing:

// including a callback as the onRendered property in the options passed to the visualization's show method
// will lead to the callback being called every time the visualization is rendered
app.visualization.get(obj).then((vis) => vis.show(el, { onRendered: () => console.log('Rendered!') }))