How to create a conditional string expression?

Hello! Been trying the library, and porting over a reporting survey from an alternative system. There’s two main things I did on said previous system, and that I ended up doing here in a similar way:

1. I ask them (optionally) for a contact username. While testing the available features on surveyjs, I wanted to place a regex restriction depending on what option they chose: If they chose Discord, they’d have to be “username#9999”, and if they chose reddit they’d use “/u/username”.
2. I make a good amount of logic jumps, giving different questions and options depending on previously selected options. I think this could be optimized, but right now it doesn’t really change the issue that much.

Which brings my current question: I’d like to include a confirmation page before the user completes the submission, something like this. But so far I can’t seem to find a way to process the answers inside the survey itself. I can get specific answers to display, but what I’d be looking for is something combining many of them, and using some only if a certain condition is met… What I wonder is, is there some way to, as examples:

• Print “{username_discord}” here only if {contact_info_choice} = “discord”
  • Alternative to this: Set {username} (“Expression (read-only)” block) depending on the value of {contact_info_choice}. Then just print {username}.
• Print {quest_type} + ( ("[" + <name conditional> + "]") if {quest_type} = "MSS") + ( {ch_number} if ({quest_type} != "D" && {quest_type} != "MSS") ) + <more similar conditions>

Here’s a gist of my current survey json

I’ve been looking around the site and customer portal for hours, solved many other questions I had but just can’t find a solution to this. I’d really appreciate if you could help me, thank you for reading.

[andrewtelnov]

@starg09 Got it! Thank you for good explanation.

Andrew

[starg09]

Oh! Wasn’t aware of those custom functions, not sure how I missed those… That works perfectly for what I was looking for, haha!

Thanks for the quick reply!

By the way, just curious, from what platform are you migrating from? and what is the reason? We have plans, not immediately so, to work on imports from popular survey platforms. Do you feel we missed something?

Well, I’ve been trying some different open source alternatives as to replace an old Google Form for a “game farming report” spreadsheet. For the last couple months I’d been trying Tripetto, which is pretty nice but still missing a couple small features. While trying to understand their custom blocks SDK as to improve the form in some ways I stumbled upon survey.js and decided to give it a shot as well, and I feel it might work pretty well for some stuff I wasn’t able to do over there 😃

Being able to migrate from their system would certainly be a nice feature, since it’s also built as a structure and not with a specific display format in mind (and can be self-hosted, so a form definition could be passed manually without much trouble).