One of the more advanced feature in QlikView is alternate state. It alllows you to have several different selections active at the same time. With set analysis expressions you can then combine your selection sets to gain valuable insights.
While alternate states are not exposed in the built-in Qlik Sense client, you can easily add them to your custom extension with just a few lines of code. Let’s see how.
Step 1: add a property panel field
The qStateName property already exists (check the Qix Engine API), so a first step is to map it to the property panel. Lets create a new section under “Addons”:
This assumes a HyperCube, $ is the default state which is always there. This is already enough for alternate state to work in your extension. If you enter a valid alternate state name in the property panel your extension will be connected to it. Problem is there has to be an alternate state in the app, and you need to know it’s name. Lets do something about that.
Step 2: add a listbox with existing alternate states.
Lets convert our property panel to a dropdown list, where the app developer can choose what state the object should be connected to. We do this by setting the component to ‘dropdown’ and adding a function to return the options:
Alternate states ar listed in the app layout structure, so we need to get the app layout and format the states in the format the property panel dropdown wants. The default state ‘$’ is not in the list, so we need to add that ourselves. For this to work you need to have the qlik module available in your extension.
Now you will have a dropdown list in your extension property panel, something like this:
Still doesn’t look much, does it… But it does it’s job. Now we just need a way to create those alternate states.
Step 3:Creating the alternate states
Well, actually you need to do this first. But there are different ways to achieve this:
- there are extensions for this
- you could do it in Engine API explorer, since its really a one-time thing
- or, you could add it to the property panel.
The property panel is not really meant for this, since we are not updating the object properties, but the app properties, but still it’s pretty easy to do. You can add something like this to the property panel:
It’s really not more complicated than that. You will get an inputfield in the propertypanel. If the user writes anything in that field, an alternate state will be created. It will then show up in the listbox, so you can use it in your extension.
It’s really not at all difficult to add alternate state support to your extension. Probably you should do something to show the user that this chart belongs to an alternate state: you can use the header for that, or add some styling or an icon for charts that are in another state. I’ll leave that for you.