MishkaCmsCore.Runtime.Resources.Validations.TemplateCompiles (Mishka CMS Core v0.0.1)

Refuses a layout, component or error page whose markup HEEx will not take, at the action boundary.

MishkaCmsCore.Runtime.Resources.Validations.PageCodeCompiles has done this for a Page since it existed, and it is the reason a page cannot even be seeded broken. The other three had nothing: the row was stored, MishkaCmsCore.Runtime.RuntimeStatus reported Ready, the compile then failed into MishkaCmsCore.Runtime.States.CompileFailureState, and the site went on serving the module it already had. The author is told nothing at any point in that.

Why this is the syntax half and not the whole compile

PageCodeCompiles builds the whole LiveView, which is about a second of work and the right price for a page — its handlers and helpers are author-written Elixir that only a real compile can judge. A layout, a component and an error page are markup plus, at most, helpers; the failure that actually happens is markup the tokenizer accepts and the engine does not:

{@a + }              parses as an expression, is not Elixir      → caught by `to_heex/1`
<div :foo={@a}>      a special attribute that does not exist     → caught HERE, and nowhere else
<div :for={@a}>      `:for` without a generator                  → the same
<:header>x</:header> a slot entry outside a component            → the same

CodeCheck.template/1 is Phoenix.LiveView.TagEngine.compile/2 — the call every one of this runtime's compilers makes — with no module built around it, so it costs milliseconds. What it cannot see is anything semantic, which is what the compile pipeline is for.

An error page is a list

It keeps error_pages, one entry per status, so "the template" is several of them; each is checked and the first fault names the status it came from, because "line 4" means nothing when the reader has five documents open in one record.

What is deliberately NOT checked

root_layout_template is not HEEx and must not be judged as if it were. MishkaCmsCore.Runtime.Compilers.ErrorCompiler compiles it with EEx.compile_string/2 and Phoenix.HTML.Engine — the classic engine — precisely because it relies on EEx interpolation inside an attribute (content="<%= Phoenix.Controller.get_csrf_token() %>"), which HEEx rejects and which the shipped seeds use. Every per-status template beside it goes through the TagEngine and is checked here; the root layout is a different language in the same record.