Joining / Importing several lists?

MIT App Inventor Help
1

Let's say I have a list of dog breeds (about 200 dog breeds), and each breed has a list of diseases (there are about 350 diseases), and I want an app where I select a dog breed and a list of it's possible diseases appear - what would be the easiest way to implement this? Thank you!

2

You can do this with a two column list:

  • breed
  • disease common to that breed.

You can import this from a spreadsheet using a Comma Separated Values (CSV) file.

Filter your table (list of lists) using the filter procedures at https://docs.google.com/document/d/12t4HLNRepCnbmcfycdF8wSHWht_D1P8hKJpTknVDChY/edit?usp=sharing

3

Alternatively, if you represent the data as a JSON dictionary, e.g.:

{
  "breed1": ["disease1", "disease2", ...],
  "breed2": ["disease3", "disease4", ...]
}

then you can use the get keys block to get a list of the breeds for populating the Elements property of a ListView component. After the user selects an item in the list view, use the get value for key in dictionary block to get the corresponding list.

4

More considerations:

  • How is your raw data arranged?
  • do you anticipate reverse queries (which breeds have this disease?)?
5

I would build up a db:

breed list:
cocker spaniel,1,5,7,9,12
labrador,2,3,4,5,9,14
.....

Where the numbers represent the index of the disease in the disease list