add counter example

examples/counter.rs

@@ -0,0 +1,36 @@
+//! Comparison example with leptos' counter example
+//! https://github.com/leptos-rs/leptos/blob/main/examples/counters/src/lib.rs
+
+use dioxus::prelude::*;
+
+fn main() {
+    dioxus_desktop::launch(app);
+}
+
+fn app(cx: Scope) -> Element {
+    let counters = use_state(cx, || vec![0, 0, 0]);
+    let sum: usize = counters.iter().copied().sum();
+
+    render! {
+        div {
+            button { onclick: move |_| counters.make_mut().push(0), "Add counter" }
+            button { onclick: move |_| { counters.make_mut().pop(); }, "Remove counter" }
+            p { "Total: {sum}" }
+            for (i, counter) in counters.iter().enumerate() {
+                li {
+                    button { onclick: move |_| counters.make_mut()[i] -= 1, "-1" }
+                    input {
+                        value: "{counter}",
+                        oninput: move |e| {
+                            if let Ok(value) = e.value.parse::<usize>() {
+                                counters.make_mut()[i] = value;
+                            }
+                        }
+                    }
+                    button { onclick: move |_| counters.make_mut()[i] += 1, "+1" }
+                    button { onclick: move |_| { counters.make_mut().remove(i); }, "x" }
+                }
+            }
+        }
+    }
+}