Minor refactoring

Author: Ayush Kumar Mishra

examples/weather_report/Cargo.toml

@@ -1,4 +1,3 @@
-# You must change these to your own details.
 [package]
 name = "rust-webassembly-weather-reports"
 description = "Weather Information System- Get the mood of your city on one click using Rust and Webassembly"
@@ -11,34 +10,14 @@ edition = "2018"
 [lib]
 crate-type = ["cdylib"]
 
-[profile.release]
-# This makes the compiled code faster and smaller, but it makes compiling slower,
-# so it's only enabled in release mode.
-lto = true
-
-[features]
-# If you uncomment this line, it will enable `wee_alloc`:
-#default = ["wee_alloc"]
-
 [dependencies]
 chrono = "0.4.11"
 reqwest = "0.10.6"
 wasm-bindgen-futures = "0.4.1"
 json= "*"
-# The `wasm-bindgen` crate provides the bare minimum functionality needed
-# to interact with JavaScript.
 wasm-bindgen = "0.2.63"
 gloo = "0.2.1"
 
-# The `web-sys` crate allows you to interact with the various browser APIs,
-# like the DOM.
 [dependencies.web-sys]
 version = "0.3.40"
-features = [
-             'Document',
-             'Element',
-             'HtmlElement',
-             'Node',
-             'Window',
-             'console'
-           ]
+features = ["Document", "Element", "HtmlElement", "Window"]

examples/weather_report/src/lib.rs

@@ -19,11 +19,6 @@ extern "C" {
     fn initialize(lat: f64, lon: f64);
 }
 
-#[wasm_bindgen]
-extern "C" {
-    fn alert(s: &str);
-}
-
 // This is like the `main` function, except for JavaScript.
 #[wasm_bindgen(start)]
 pub fn main_js() -> Result<(), JsValue> {
@@ -36,7 +31,11 @@ pub fn main_js() -> Result<(), JsValue> {
     let input_box = create_input_box(&document);
     search_div.append_child(&input_box)?;
     let submit_box = create_submit_box(&document);
-    let temp_div = create_div(&document, "tempDetail", "ReportStyles-mainContainer col-md-12 maincontainer");
+    let temp_div = create_div(
+        &document,
+        "tempDetail",
+        "ReportStyles-mainContainer col-md-12 maincontainer",
+    );
     let first_div = document.create_element("div")?;
     let second_div = create_div(&document, "second_div", "col-md-6");
     let third_div = create_div(&document, "third_div", "ReportStyles-innerDiv");
@@ -191,11 +190,15 @@ pub fn main_js() -> Result<(), JsValue> {
         });
     });
 
+    // When a Closure is dropped it will invalidate the associated JS closure.
+    // Here we want JS callback to be alive for the entire duration of the program.
+    // So we used `forget` leak this instance of Closure.
+    // It should be used sparingly to ensure the memory leak doesn't affect the program too much.
     on_click.forget();
     Ok(())
 }
 
-fn create_div(document: &Document, id: &str, class:&str) -> Element {
+fn create_div(document: &Document, id: &str, class: &str) -> Element {
     let div = document.create_element("div").unwrap();
     div.set_id(id);
     div.set_class_name(class);
@@ -226,7 +229,7 @@ fn create_input_box(document: &Document) -> Element {
 // Get response from weather api
 async fn get_response(location: &str) -> JsonValue {
     let url1 = "http://api.openweathermap.org/data/2.5/weather?q=";
-    let url2 = "&appid=<apikey>";
+    let url2 = "&appid=<apiKey>";
 
     let url = [url1, location, url2].concat();