MARKLESS_TEMPLATE_EXPRESSION_UNSUPPORTED

A markup expression that reads state needs a route the page can follow: a Markless compiler error.

Error from the compiler, while it builds your .tsrx files.

What happened

Markless prints the message, the reason, and a suggestion:

MARKLESS_TEMPLATE_EXPRESSION_UNSUPPORTED: <target> is written as `<source>`, which reads state but is not an expression this compiler can keep current.
An expression with no graph node behind it renders once, from whatever the value was at render, and a later write never reaches it - so the page would show a stale value and nothing would say so.
Write a plain read (`group.value`), or an expression built only from reads, operators and method calls on those reads. If the value needs a function of your own, put that function inside a `computed()` and read the computed here.
https://markless.dev/errors/MARKLESS_TEMPLATE_EXPRESSION_UNSUPPORTED

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How to fix it

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Where it comes from

@markless/compiler raises this code. Source:

• packages/compiler/src/passes/semantic-graph/diagnostics.ts

Read how to read a Markless error, or go back to all error codes.