my.property
is not a valid property. First of all you must prefix a property with either lib
or temp
. The first one is a "Library" object and will be cached while the second one is a "Temporary" object and will be deleted after runtime.
Besides that, your example doesn't include any TypoScript objects. So even if it works, it won't output anything.
So this should work:
lib.myproperty = TEXT
lib.myproperty.value = Hello world!
page = PAGE
page {
# PAGE is a COA so we need a numerical index
10 < lib.myproperty
}
Output in browser:
Hello world!