From b4c143b84ad600ff53ec8f9a0fa371a32e742ac1 Mon Sep 17 00:00:00 2001
From: Jonathan Cornaz <jonathan.cornaz@gmail.com>
Date: Sun, 3 Nov 2024 09:01:20 +0100
Subject: [PATCH] support `none` element

---
 README.md            | 10 ++++++++--
 src/elt.rs           | 18 ++++++++++++++++++
 src/lib.rs           | 15 ++++++++++++---
 tests/render_spec.rs |  2 ++
 4 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 6d22dd2..2c889a9 100644
--- a/README.md
+++ b/README.md
@@ -18,8 +18,14 @@ assert_eq!(greeting.to_string(), r#"<h1 class="bold">Hello world!</h1>"#);
 Because those are simple rust functions, it is easy to leverage rust features like conditions, loops and iterators:
 
 ```rust
-let list = ul([], (1..=3).map(|n| li([], [n.to_string().into()])));
-assert_eq!(list.to_string(), "<ul><li>1</li><li>2</li><li>3</li></ul>");
+let list_values = true;
+let element = if list_values {
+ ul([], (1..=3).map(|n| li([], [n.to_string().into()])))
+} else {
+ text("no value")
+};
+
+assert_eq!(element.to_string(), "<ul><li>1</li><li>2</li><li>3</li></ul>")
 ```
 
 
diff --git a/src/elt.rs b/src/elt.rs
index a36cdb5..8f1bb0e 100644
--- a/src/elt.rs
+++ b/src/elt.rs
@@ -8,6 +8,24 @@ use alloc::{borrow::Cow, string::String, vec::Vec};
 
 use crate::{Attribute, Element, ElementInner};
 
+/// Renders nothing. Useful fo conditional rendering.
+///
+/// # Example
+///
+/// ```
+/// use fun_html::{Element, elt::{text, none}};
+///
+/// let say_hello = true;
+/// let element: Element = if say_hello {
+///   text("Hello")
+/// } else {
+///   none()
+/// };
+/// ```
+pub fn none() -> Element {
+    Element(ElementInner::None)
+}
+
 /// `<div>`
 pub fn div(
     attributes: impl IntoIterator<Item = Attribute>,
diff --git a/src/lib.rs b/src/lib.rs
index 00238d5..7471282 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -27,9 +27,16 @@
 //! Because those are simple rust functions, it is easy to leverage rust features like conditions, loops and iterators:
 //!
 //! ```
-//! # use fun_html::{elt::{li,ul}};
-//! let list = ul([], (1..=3).map(|n| li([], [n.to_string().into()])));
-//! assert_eq!(list.to_string(), "<ul><li>1</li><li>2</li><li>3</li></ul>");
+//! # use fun_html::{elt::{li,ul,text}};
+//!
+//! let list_values = true;
+//! let element = if list_values {
+//!   ul([], (1..=3).map(|n| li([], [n.to_string().into()])))
+//! } else {
+//!   text("no value")
+//! };
+//!
+//! assert_eq!(element.to_string(), "<ul><li>1</li><li>2</li><li>3</li></ul>")
 //! ```
 //!
 //! ## Escape hatches
@@ -103,6 +110,7 @@ enum ElementInner {
     Script(Cow<'static, str>),
     Raw(Cow<'static, str>),
     Multiple(Vec<Element>),
+    None,
 }
 
 /// An attribute
@@ -214,6 +222,7 @@ impl Display for Element {
                     write!(f, "{elt}")?;
                 }
             }
+            ElementInner::None => (),
         }
         Ok(())
     }
diff --git a/tests/render_spec.rs b/tests/render_spec.rs
index 22f3e1e..172f01a 100644
--- a/tests/render_spec.rs
+++ b/tests/render_spec.rs
@@ -63,6 +63,8 @@ fn should_render_attribute(#[case] attr: Attribute, #[case] expected: &str) {
 }
 
 #[rstest]
+#[case(none(), "")]
+#[case([div([], []), div([], [])].into(), "<div></div><div></div>")]
 #[case(text("hello"), "hello")]
 #[case(text("hello".to_string()), "hello")]
 #[case("hello".into(), "hello")]