✨ [pagetop] Añade la librería principal de PageTop

El crate pagetop reúne algunos de los crates más estables y populares
del ecosistema Rust para proporcionar un conjunto completo de
funcionalidades que pueden extenderse y adaptarse a las necesidades
específicas de cada aplicación para crear soluciones web modulares,
extensibles y configurables.

pagetop/src/core/theme/definition.rs

@@ -0,0 +1,59 @@
+use crate::core::package::PackageTrait;
+use crate::global;
+use crate::html::{html, Markup};
+use crate::locale::L10n;
+use crate::response::page::Page;
+
+pub type ThemeRef = &'static dyn ThemeTrait;
+
+/// Los temas deben implementar este "trait".
+pub trait ThemeTrait: PackageTrait + Send + Sync {
+    fn regions(&self) -> Vec<(&'static str, L10n)> {
+        vec![("content", L10n::l("content"))]
+    }
+
+    fn render_head(&self, page: &mut Page) -> Markup {
+        let viewport = "width=device-width, initial-scale=1, shrink-to-fit=no";
+        html! {
+            head {
+                meta charset="utf-8";
+
+                @if let Some(title) = page.title() {
+                    title { (global::SETTINGS.app.name) (" | ") (title) }
+                } @else {
+                    title { (global::SETTINGS.app.name) }
+                }
+
+                @if let Some(description) = page.description() {
+                    meta name="description" content=(description);
+                }
+
+                meta name="viewport" content=(viewport);
+                @for (name, content) in page.metadata() {
+                    meta name=(name) content=(content) {}
+                }
+
+                meta http-equiv="X-UA-Compatible" content="IE=edge";
+                @for (property, content) in page.properties() {
+                    meta property=(property) content=(content) {}
+                }
+
+                (page.context().render_assets())
+            }
+        }
+    }
+
+    #[allow(unused_variables)]
+    fn before_render_body(&self, page: &mut Page) {}
+
+    fn render_body(&self, page: &mut Page) -> Markup {
+        html! {
+            body id=[page.body_id().get()] class=[page.body_classes().get()] {
+                (page.context().render_region("content"))
+            }
+        }
+    }
+
+    #[allow(unused_variables)]
+    fn after_render_body(&self, page: &mut Page) {}
+}