This doc explains why the push template notifications look slightly different than the default notifications. And also covers the rendering issues encountered with Push templates.
1. Size of Push template notifications
The height of Push notification in collapsed mode is 64 dp and expanded mode is 256 dp.
Due to this, you might see the height of a default notification bigger than the customised notification in collapsed mode. The reason for this is that the custom push notification with height > 64 dp was failing on some devices. And since, dynamic or flexible heights is not feasible, we restricted the height to the dimensions mentioned above.
2. Some users receive stylised push notification without background color
We observed that some of our client users received the push notification with HTML content but without the background color. Lets understand the reason behind this:
Whenever you configure a push template notification with
- HTML text (meaning, you have either set the text as bold/ italic/ underlined/ strikedthrough or added some text color) and
- Background color
The SDK renders the notification in the following sequence:
- Renders a basic push notification with HTML text fields & app icon
- Then, it tries to draw the custom layout containing background color. If you configured an image, then SDK will try to download the image in parallel
Since SDK only gets ~10 secs to render the entire notification, sometimes due to poor internet connectivity or other network issues, the background rendering or image rendering or both might fail. If both fails, then this would result in showing a push notification with only the stylised text and NO background color.
Impact of background color rendering failure:
1. If you set your text color as white, then users would end up seeing a blank notification as shown below if their device theme is set as light mode
2. If you set your text color as black, then users would end up seeing a blank notification as shown below if their device theme is set as dark mode
So, we suggest that:
1. wherever possible, use text colors that contrast with light & dark backgrounds.
2. While creating campaigns on MoEngage dashboard, check preview in both dark & light mode to make sure the notification looks fine in both the modes.
3. Color inversion in dark mode (device specific issue)
Another rare issue we have observed is that colors get inverted in dark mode when stylised Push is sent. This has been observed only on a few Oppo devices running on Android 10. Though we have taken utmost precautions to prevent this issue, but there seems to be some bug with ColorOS (operating system created by OPPO) due to which it is beyond the scope of MoEngage.