Guestbook

This template runs Lua on its host. The source below is not executed by this web preview.

return function(ctx)
  local P=ctx.page
  local entries=ctx.read('entries',{})
  if ctx.method=='POST' and ctx.path=='/sign' then
    local text=tostring(ctx.fields.message or ''):sub(1,240)
    if text:match('%S') then
      entries[#entries+1]={text=text,id=ctx.requestId}
      while #entries>30 do table.remove(entries,1) end
      ctx.write('entries',entries)
    end
    return {kind='redirect',path='/'}
  end
  if ctx.path~='/' then return nil end
  local children={P.heading{text='Leave a little warmth'},P.paragraph{text='A guestbook for passing travelers. Notes are public.'}}
  for _,entry in ipairs(entries) do children[#children+1]=P.paragraph{text=entry.text} end
  children[#children+1]=P.form{action='/sign',children={P.input{name='message',text='Your note'},P.submit{text='Sign guestbook'}}}
  return {kind='page',page=P.document('Guestbook',children)}
end

{
  "version": 1,
  "title": "Guestbook",
  "children": [
    {
      "type": "heading",
      "text": "Guestbook"
    },
    {
      "type": "paragraph",
      "text": "Leave a note for the next traveler."
    },
    {
      "type": "columns",
      "children": [
        {
          "type": "section",
          "children": [
            {
              "type": "heading",
              "text": "Explore"
            },
            {
              "type": "paragraph",
              "text": "Built for our world."
            }
          ]
        },
        {
          "type": "section",
          "children": [
            {
              "type": "heading",
              "text": "Make it yours"
            },
            {
              "type": "paragraph",
              "text": "Edit this page with Lantern."
            }
          ]
        }
      ]
    },
    {
      "type": "link",
      "text": "Back to Lantern",
      "href": "ln://home"
    }
  ]
}