Musson Industrial's Embr-Periscope Module

3rd Party Modules
62

No, unfortunately there isn’t a way to do lazy loading for views.

I think the virtualized feature should work though, but I can’t say I’ve tested it; any feedback you could provide about it would be helpful.

64

Think I came up with a solution. Atleast it seems to work quite good.

I load images from a database stored as varbinary and I want to stop this if the Swiper contains alot of images.

  • Added "index" to params on the Embedded Views (Ignition function).
  • Added "load"-bool to params on the Embedded Views with a change script.
def valueChanged(self, previousValue, currentValue, origin, missedEvents):
	if currentValue.value == True and self.view.custom.image == "":
		import base64
		sqlParams = {"imageId": self.view.params.imageId}
		image = system.db.runNamedQuery("getImage", sqlParams).getValueAt(0,0)
		self.view.custom.image = base64.b64encode(image)
  • Set "load" to true for the first 3 views and the rest to false when creating the instances.
  • Added a Custom Method to the view with Swiper.
def realIndex(self):
	component = self.getChild("Swiper")
	
	proxy = component.getJavaScriptProxy("swiper")
	currentIndex = proxy.runBlocking('''() => this.realIndex''')
	
	if currentIndex != self.view.custom.currentIndex:
		self.view.custom.currentIndex = currentIndex
		
		for i in range(3):
			self.getChild("Swiper").props.instances[currentIndex + i].viewParams.load = True
  • Calling the Custom Method through a "onPointerDown" event.
def runAction(self, event):
	self.parent.realIndex()

This seems to work fine for me. But I'm not really sure how effecient it is. And depending on the Swiper settings it could cause the message to not get triggered enough (more dots (have to preload more then +2), or with a scroll etc.). If there was a better way to get the current index it would probably work better.

EDIT: Used Message Handler on the Embedded Views to load the images but felt wrong to send out a message that ~100 views handled on each Swiper-click. This solution feels better, but I'm open for a better one :slight_smile: