Check for multiple object properties in AppleScript - applescript

Question

I wrote an AppleScript that shall check existing reminders in the Reminders app for their name. If a reminder with the given name (Erinnerung) does not exist one shall be created.
But the following code does check the uncompleted reminders only:
tell application "Reminders"
if exists (reminders whose name is Erinnerung) then
else
set newremin to make new reminder
set name of newremin to Erinnerung
end if
end tell
So I tried to check for the name and the completion status at once:
tell application "Reminders"
if exists (reminders with properties {name:Erinnerung, completed:true}) then
else
set newremin to make new reminder
set name of newremin to Erinnerung
end if
end tell
But then I'm getting an error:
"„properties:true“ kann nicht diesem „reminders“ folgen."
("„properties:true“ can not follow this „reminders“")
Why does the Reminders app check for uncompleted reminders only? And why can't I check for two properties at once? Does anyone know what I am doing wrong?

Answer 1

To filter objects by one or more properties filter the array and count the elements of the result.
One property (I changed the variable Erinnerung to a literal string)
tell application "Reminders"
set erinnerungen to reminders whose name is "Erinnerung"
if (count erinnerungen) is 0 then
set newremin to make new reminder
set name of newremin to "Erinnerung"
end if
end tell
Two properties
tell application "Reminders"
set erinnerungen to reminders whose name is "Erinnerung" and completed is true
if (count erinnerungen) is 0 then
set newremin to make new reminder
set name of newremin to "Erinnerung"
end if
end tell
If you want to check an object which can be referenced by name you can also use this
tell application "Reminders"
if not (exists reminder "Erinnerung") then
set newremin to make new reminder
set name of newremin to "Erinnerung"
end if
end tell