The "GetObject" method will give you a handle to the object in you ask for which you can use to perform method calls for that particular object. Typically you will use the returned handle as argument to operations such as "GetProperties" and "GetLayout" to inspect the definition of the object and the values computed for it by the engine. You'll find lots of information on the Engine API at this location:
In particular, you might want to look into these pages to learn about the concept of generic objects:
Keep in mind though, that the engine has no knowledge of how to actually render the visualizations. It is the client that handles that part, and it is therefore not possible to extract rendered images from the engine API.
Thanks for Reply, So that mean, the JSON only send the data, not the graph?
in my case, if i want showing the graph from QlikSense Dashboard, i should recreate the object with JSON data that i get from Engine API right? we should render the visualization manually with the data that we get from JSON.
Yes, the engine can only provide you with the data of the objects. To embed visualizations in other environments than Qlik Sense, people will typically use mashups. You can find more information about that concept here:
Or, if you just want to display a single visualization, then you might want to look into this: