Check whether an user input is a valid date or not

General
1

I have a telegram bot which connects to my node-red and triggers a flow which generates a report. for it to work correctly, i need the user to always input the date format in YYYY-MM-DD format, when the user enters correctly, it generates a report and sends a report back to telegram.
however if the user sends an incorrect syntax, the report obviously doesnt generate, i want to send the user a message the syntax was incorrect.

is there a way to

  1. check if the entered string is a valid date in the format YYYY-MM-DD and/or
  2. restrict the user to enter always in the given format. or
  3. generate a inline keyboard in telegram whcih is similar to a datepicker. (raised a separate topic in forum already)

any help / hint appreciated.

2

Here is a posibility

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[edit]
$moment().isAfter()
May work better if you want to limit valid dates by years.

[{"id":"7a0882e159aa5076","type":"inject","z":"b9860b4b9de8c8da","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"01-01-1970","payloadType":"str","x":190,"y":4260,"wires":[["c7f2fa132c1fee66"]]},{"id":"c7f2fa132c1fee66","type":"change","z":"b9860b4b9de8c8da","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"$moment($replace($$.payload, \"/\", \"-\"), \"DD-MM-YYYY\").isAfter(\"12-12-1969\")","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":440,"y":4360,"wires":[["4ca64e0ac228f163"]]},{"id":"781cdcca88fe5c64","type":"inject","z":"b9860b4b9de8c8da","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"24/05/2023","payloadType":"str","x":210,"y":4320,"wires":[["c7f2fa132c1fee66"]]},{"id":"e9aae64c35e743f1","type":"inject","z":"b9860b4b9de8c8da","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"24-05-223","payloadType":"str","x":200,"y":4380,"wires":[["c7f2fa132c1fee66"]]},{"id":"a4d56691df5e1b59","type":"inject","z":"b9860b4b9de8c8da","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"05/24/2023","payloadType":"str","x":210,"y":4440,"wires":[["c7f2fa132c1fee66"]]},{"id":"4ca64e0ac228f163","type":"debug","z":"b9860b4b9de8c8da","name":"debug 314","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","statusVal":"","statusType":"auto","x":650,"y":4360,"wires":[]}]

Will return true or false

3

this would satisfy my urgent need. thanks!
I understand the logic behind it, but would never be able to build a equation with jsonata like this. ever.
my ulterior goal is to get some 'datepicker' interface in telegram. still searching for it.

4

Another approach, while you search, might be to use the node-red-contrib-moment node to force conversion to the format you want. Since it would let the user enter a "wrong" format, it might be best to show what the node thinks he wants and ask for confirmation. (Note the difference in how "24-05-223" is handled.)

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