feat: Implement custom submission message

[susnux]

• Resolves Allow for custom message and/or redirect after submission #385

ℹ️ Summary

Users can configure a custom text which is shown if a users submits the form (custom "Thank you message").
It can be formatted using markdown, so it also allows the requested link feature (e.g. to link back to a website).

🖼️ Screenshots

Form submitted	Editing the message	Preview the message

[Chartman123]

@susnux Nice addition :) Should we hide the message input field behind a switch? [ ] Show custom message

[codecov]

Codecov Report

Merging #1659 (812a637) into main (6c0ad5d) will decrease coverage by 0.24%.
Report is 5 commits behind head on main.
The diff coverage is 11.76%.

❗ Current head 812a637 differs from pull request most recent head fed3d4c. Consider uploading reports for the commit fed3d4c to get more accurate results

Additional details and impacted files

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- Coverage     43.19%   42.96%   -0.24%     
- Complexity      611      613       +2     
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  Lines          2475     2486      +11     
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- Hits           1069     1068       -1     
- Misses         1406     1418      +12     

[susnux]

Should we hide the message input field behind a switch? [ ] Show custom message

Unsure about this, what do you think looks better? (For me both variants have equal pros and cons)

[Chartman123]

Unsure about this, what do you think looks better? (For me both variants have equal pros and cons)

Using the switch we would surely need one more column in the DB, but then could also have an empty submission message. I think this is also a question for the designers. If we add the switch, we should also indent the text box under the text of the switches. Would you like to bring it up in the design team chat?

[jancborchardt]

Nice idea @susnux! And yep, I think @Chartman123’s suggestion about doing it as a switch is good, keeps it cleaner too since most people are likely to keep the original submission message. And then we can also add some grey hint text when it’s enabled saying something like:
"Message to show after form submission. Note that this can not be translated."

[susnux]

@Chartman123 @jancborchardt

Implemented the checkbox:

[Chartman123]

I had another look at the corresponding issue and saw that there was a request for customizing the title message of the submission page, too. Would you like to add this into this PR as well?

Other than that, please update the API docs :)

[susnux]

@jancborchardt the setting do look like this now:

[Chartman123]

Looks good now. So only the following things are remaining:

• add the new prop to docs/API.md and docs/DataStructure.md, add info that prop is only available with higher API level
• raise API level?
• What to do about the title? Always keep the default or make it customizable, too?
• Squash commits into one, do a rebase

clicked wrong button

[susnux]

@Chartman123 done with the todos

raise API level?

I would say no as we did not change it, there are no new routes, we did not increase the API level for new option keys before (e.g. extraSettings).

What to do about the title? Always keep the default or make it customizable, too?

can we do this in a follow up? I would like to discuss some options before and this PR at least provides the functionality requested.

[Chartman123]

we did not increase the API level for new option keys before (e.g. extraSettings).

I'm no expert in API level definitions... But fine for me to stay with 2.1

can we do this in a follow up?

Fine for me 👍🏻