Two tags two values from two databases (ex. firebase) in one listview

MIT App Inventor Help
1

Hello, someone can help me??
It can possible?
Thanks

2

Ask the first database for the first value.
When that arrives, save it somewhere and ask the second database for the second value.
When the second data arrives, combine it with the saved data.

3

Thanks, and if i've one database and two records, how can i do to view those value into a one listview?
Because when arrive (datachanged) the first record with one tag i see the value in the listview, But when arrive (Gotvalue) the second tag and the second value, the first disappears and I only see the second.

4

image
image1229×293 38.6 KB

image
image1228×315 36.2 KB

5

image
image1308×344 36.3 KB

6

Sometimes it is easier to answer a question for any number n than for a fixed number like 2.

Set up two global lists, initially empty:

  • tags I want to get
  • values that came back from Firebase

add tag1 to the list tags I want to get
add tag2 to the list tags I want to get
Ask Firebase for the tag at item 1 of tags I want to get

When a tag/value arrives from Firebase:
if tag is in list tags I want to get then

  • add value to list values that came back from Firebase
  • remove tag from list tags I want to get (item 1)
  • if list tags I want to get is empty list, then
    • set listview Elements to list values that came back from Firebase
  • else
    • Ask Firebase for the tag at item 1 of tags I want to get

By the way, Fontsize can't be a list. It's a number to set how big the text looks.