String manipulation

MIT App Inventor Help
8

Hello szymekkart250

Does your App have to download the questions from a web page? If it does have to, is that website yours? If it is yours, you can collect a CSV file instead of HTML. If you don't have to download you can store a CSV file in the App, or send me that file and I can convert it into a Blocks List.

10

I download this file from URL. A couple of replies above there is the process of downloading the json. Thanks for Your help!

11

I download this file from URL. A couple of replies above there is the process of downloading the json.

12

What I mean is - does the App only ever perform the download once, only use this data?

13

The idea is that I download the data once, when the user want to start a quiz game. Later I want to display this data on the screen. So yeah, somehow I can tell that it performs the download once, but there can be a second download when sbd want to play another game.

14

So it sounds as though you have control of the online data - so why not download a CSV file that has no formatting issues?

15

@ChrisWard How do I get a CSV file? Is it done by using the "Web.GotText" and processing the "responseContent"? I havn't worked with it so far. Thanks!

16

Is it your own website?

17

No, this was a general question following the discussion here I'm interested in.

18

So you can only get a CSV if the website owner makes one available.

1 Like
19

@ChrisWard Ah, thank you!

20

Can you direct the Web1 GotText responseContent to a temporary Text Box, copy it, send it to yourself via email and post it here as a text file? Or alternatively let us have the URL.

21

Here is a sample url

https://opentdb.com/api.php?amount=10&type=multiple

It will return different questions every time

1 Like
28

@TIMAI2 Oh, thanks, I'm going to test it/make first experience with it later on.

31

Would be good to hear from ABG, he is our JSON Guru.

1 Like
33

Hi all, I just dropped into this thread.

Without any coding, here are my thoughts ...

  • The JSON looks okay.
  • The web markup in the questions suggest to me that maybe plopping the questions into a HTML Label or WebViewer would let them do their appearance thing without having to clean out any markup.
  • JSON Strings turned into objects have the right to come back in a different order than the original JSON strings, since the dictionary internals are supposed to be accessed by key.
  • I see no need for bracket and quote removal in answers, if they are manipulated as lists and offered for display as ListView Elements.
  • a list append and a list randomizer call would be needed before loading a ListView Elements with answer options. (I have one in stock, if any one needs.)

I could wire up a solution, if any one has a recent .aia to build on.

34

I took a first whack at the project, and discovered that the answers might have markup also, so the ListView is not up to the task.

I would have to rework this to use buttons, and restrict the total number of possible answers to the length of my button list.

blocks
blocks1022×2267 314 KB
Capture Correct ListView is inadequate opentdb.aia (5.5 KB) Wrong

35

I managed to remove the internal answer markup using the Web1.HTMLDecode block.
With no markup showing, the ListView was up to the task.

blocks
blocks1022×2742 369 KB
Capture Correct Decoded
Designer
Designer762×408 51.4 KB
opentdb.aia (6.0 KB) Wrong
(I figured, if HTMLEncode adds markup, then HTMLDecode must remove markup.)

This should be my final version .

2 Likes
36

(added to FAQ)

1 Like
37

@ABG Thank you very much for this detailed presentation. I've got a first idea of how to use JSON stuff along with the web component and its blocks that I didn't use so far. I've played around a bit and additionally found an example in the web http://sparse-dense.blogspot.com/2020/03/decoding-json-by-using-new-dictionaries.html, to my opinion worth to put an eye on it, as well as a YT video by @ewpatton Evan Patton https://www.youtube.com/watch?v=8rhw7JIB9R0 :slight_smile:

1 Like