Using Function Calls (data-*@)

Hi, I would like to build a form in Grav for customors to sign in for upcomming events.
The events are defined as list items on another page

    title: 'Datenschutz in der TGI'
    kurzbeschreibung: 'Das Seminar bietet neben praktischen Umsetzungsmöglichkeiten und Musterformularen speziell auf den tiergestützten Bereich zugeschnittene Inhalte rund um das Thema "Datenschutz".'
    bild: Datenschutz.jpg
    pdf1: 'Datenschutz in der TGI.pdf'
    pdf1txt: 'Weitere Infos'
    datum: 01.02.2019
    zeit: '14:00 - 20:00 Uhr'
    bildbanner: 'Jetzt buchen!'
    verfallsdatum: '02-02-2019 16:15'
    show: true
    title: 'Selbsterfahrungstag mit verschiedenen Tieren (Hund, Pferd & Ziege)'
    bild: blanko.png
    datum: "03.03.2019\t"
    show: true

so I would like to query all title fields and make them available in an option field in a form on another page.

I am not sure, if the latest Grav-Version can make this work anyhow. Is it possible to use data-*@ calls in a form for that purpose? I have no clue how that could work…

Are the events defined in an html list in the content of the other page, or are they part of the frontmatter? I think you would have to write your own php function to get them if they are an html list.

the events are entered via a form in the admin panel, the code i posted was a copy of the yaml header of the event page

I’m still learning Grav so I don’t have a complete answer for you, but you’d need to get this page as a collection on your form page I think. That would make the list available as a twig variable in your form. I’m not sure how you would get the titles.