feat(slhx): render hemplate views into slots

Add render_html plus slot render_view helpers that call hemplate render_into, and migrate a kanban effect path from explicit SafeHtml/html handling to the renderable-view helper.

req: view/001

req: html_safety/002

slhx/Cargo.toml

@@ -7,5 +7,6 @@ edition.workspace = true
 path = "src/lib.rs"
 
 [dependencies]
+hemplate = { path = "../../hemplate/hemplate" }
 slhx-core = { path = "../slhx-core" }
 slhx-derive = { path = "../slhx-derive" }

slhx/src/lib.rs

@@ -6,11 +6,52 @@
 pub use slhx_core::*;
 pub use slhx_derive::{app, component, form, handler, surface};
 
+pub fn render_html(view: &impl hemplate::Hemplate) -> SafeHtml {
+    let mut html = String::new();
+    view.render_into(&mut html)
+        .expect("hemplate view renders into slhx effect payload");
+    SafeHtml::trusted(html)
+}
+
+pub trait RenderSlotExt {
+    fn render_view(self, view: &impl hemplate::Hemplate) -> Effect;
+}
+
+impl<T> RenderSlotExt for Slot<T> {
+    fn render_view(self, view: &impl hemplate::Hemplate) -> Effect {
+        self.html(render_html(view))
+    }
+}
+
+pub trait RenderKeyedSlotExt<K> {
+    fn append_view(self, key: K, view: &impl hemplate::Hemplate) -> Effect;
+    fn prepend_view(self, key: K, view: &impl hemplate::Hemplate) -> Effect;
+    fn replace_view(self, key: K, view: &impl hemplate::Hemplate) -> Effect;
+}
+
+impl<K, T> RenderKeyedSlotExt<K> for KeyedSlot<K, T>
+where
+    K: ToString,
+{
+    fn append_view(self, key: K, view: &impl hemplate::Hemplate) -> Effect {
+        self.append_html(key, render_html(view))
+    }
+
+    fn prepend_view(self, key: K, view: &impl hemplate::Hemplate) -> Effect {
+        self.prepend_html(key, render_html(view))
+    }
+
+    fn replace_view(self, key: K, view: &impl hemplate::Hemplate) -> Effect {
+        self.replace_html(key, render_html(view))
+    }
+}
+
 pub mod prelude {
     pub use slhx_core::{
         navigate, push, redirect, replace, Atom, BuildFingerprint, ComponentRef, CssClass,
         CssClasses, Effect, EventName, Form, FormModel, FormValue, Handle, IntoEffect, KeyedSlot,
         Slot,
     };
+    pub use crate::{render_html, RenderKeyedSlotExt, RenderSlotExt};
     pub use slhx_derive::{app, component, form, handler, surface};
 }