web-sys: Weather report
This example makes an HTTP request to OpenWeather API,
parses response in JSON and render UI from that JSON. It also shows the usage of
spawn_local
function for handling asynchronous tasks.
Please add your api key in get_response() before running this application.
src/lib.rs
#![allow(unused_variables)]
fn main() {
extern crate chrono;
extern crate reqwest;
use chrono::prelude::DateTime;
use chrono::Utc;
use std::time::{Duration, UNIX_EPOCH};
use gloo::events::EventListener;
use json::JsonValue;
use wasm_bindgen::prelude::*;
use wasm_bindgen_futures::spawn_local;
use web_sys::Document;
use web_sys::Element;
use web_sys::HtmlInputElement;
#[wasm_bindgen(module = "/util.js")]
extern "C" {
fn initialize(lat: f64, lon: f64);
}
#[wasm_bindgen(start)]
fn run() -> Result<(), JsValue> {
let window = web_sys::window().expect("no global `window` exists");
let document = window.document().expect("should have a document on window");
let body = document.body().expect("document should have a body");
// Manufacture the element we're gonna append
let search_div = create_div(&document, "search", "ReportStyles-secondDiv col-md-12");
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 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");
let fourth_div = create_div(&document, "cityName", "ReportStyles-city");
let table_div = document.create_element("table")?;
table_div.set_class_name("ReportStyles-table table-bordered table-striped");
let tbody_div = document.create_element("tbody")?;
let ftr_div = document.create_element("tr")?;
let ftd_div = document.create_element("td")?;
ftd_div.set_class_name(" ReportStyles-firstTd");
let img_div = document.create_element("div")?;
img_div.set_id("temp");
let std_div = document.create_element("td")?;
std_div.set_class_name(" ReportStyles-secondTd");
let weather_div = document.create_element("div")?;
weather_div.set_id("weather");
ftr_div.append_child(&ftd_div)?;
ftd_div.append_child(&img_div)?;
ftr_div.append_child(&std_div)?;
std_div.append_child(&weather_div)?;
let str_div = document.create_element("tr")?;
let ptd_div = document.create_element("td")?;
ptd_div.set_class_name(" ReportStyles-td");
ptd_div.set_inner_html("Pressure");
let sptd_div = document.create_element("td")?;
sptd_div.set_id("pressure");
str_div.append_child(&ptd_div)?;
str_div.append_child(&sptd_div)?;
let ttr_div = document.create_element("tr")?;
let htd_div = document.create_element("td")?;
htd_div.set_class_name(" ReportStyles-td");
htd_div.set_inner_html("Humidity");
let shtd_div = document.create_element("td")?;
shtd_div.set_id("humidity");
ttr_div.append_child(&htd_div)?;
ttr_div.append_child(&shtd_div)?;
let sunr_tr_div = document.create_element("tr")?;
let sunr_td_div = document.create_element("td")?;
sunr_td_div.set_class_name(" ReportStyles-td");
sunr_td_div.set_inner_html("Sunrise[UTC]");
let sunr_s_td_div = document.create_element("td")?;
sunr_s_td_div.set_id("sunrise");
sunr_tr_div.append_child(&sunr_td_div)?;
sunr_tr_div.append_child(&sunr_s_td_div)?;
let suns_tr_div = document.create_element("tr")?;
let suns_td_div = document.create_element("td")?;
suns_td_div.set_class_name(" ReportStyles-td");
suns_td_div.set_inner_html("Sunset[UTC]");
let suns_s_td_div = document.create_element("td")?;
suns_s_td_div.set_id("sunset");
suns_tr_div.append_child(&suns_td_div)?;
suns_tr_div.append_child(&suns_s_td_div)?;
let geo_tr_div = document.create_element("tr")?;
let geo_htd_div = document.create_element("td")?;
geo_htd_div.set_class_name(" ReportStyles-td");
geo_htd_div.set_inner_html("Geo coords");
let geo_shtd_div = document.create_element("td")?;
geo_shtd_div.set_id("geocoords");
geo_tr_div.append_child(&geo_htd_div)?;
geo_tr_div.append_child(&geo_shtd_div)?;
tbody_div.append_child(&ftr_div)?;
tbody_div.append_child(&str_div)?;
tbody_div.append_child(&ttr_div)?;
tbody_div.append_child(&sunr_tr_div)?;
tbody_div.append_child(&suns_tr_div)?;
tbody_div.append_child(&geo_tr_div)?;
table_div.append_child(&tbody_div)?;
third_div.append_child(&fourth_div)?;
third_div.append_child(&table_div)?;
let map_div = document.create_element("div")?;
map_div.set_class_name("col-md-6");
let map_canvas_div = document.create_element("div")?;
map_canvas_div.set_class_name(" ReportStyles-mapCanvas");
map_canvas_div.set_id("map_canvas");
map_div.append_child(&map_canvas_div)?;
second_div.append_child(&third_div)?;
first_div.append_child(&second_div)?;
first_div.append_child(&map_div)?;
temp_div.append_child(&first_div)?;
search_div.append_child(&submit_box)?;
body.append_child(&search_div)?;
body.append_child(&temp_div)?;
let on_click = EventListener::new(&submit_box, "click", move |_event| {
let input_value = document
.get_element_by_id("name")
.unwrap()
.dyn_into::<HtmlInputElement>()
.unwrap()
.value();
let temp_d = temp_div.clone();
let city = fourth_div.clone();
let image = img_div.clone();
let weather = weather_div.clone();
let pressure = sptd_div.clone();
let humidity = shtd_div.clone();
let sunrise = sunr_s_td_div.clone();
let sunset = suns_s_td_div.clone();
let geo = geo_shtd_div.clone();
let input_value: &'static _ = Box::leak(Box::new(input_value));
let response = get_response(input_value);
spawn_local(async move {
let parsed = response.await;
let lon = parsed["coord"]["lon"].to_owned().as_f64().unwrap();
let lat = parsed["coord"]["lat"].to_owned().as_f64().unwrap();
initialize(lat, lon);
let city_name: &str = &parsed["name"].to_owned().to_string();
let country_name: &str = &parsed["sys"]["country"].to_owned().to_string();
let place = [city_name, ",", country_name].concat();
let icon = &parsed["weather"][0]["icon"].to_owned().to_string();
let src = [
"<img src='http://openweathermap.org/img/w/",
icon,
".png'>",
" ",
]
.concat();
let temp = (parsed["main"]["temp"].to_owned().as_f64().unwrap() - 273.15) as i64;
let content = [src, temp.to_string()].concat();
let p: &str = &parsed["main"]["pressure"].to_owned().to_string();
let h: &str = &parsed["main"]["humidity"].to_owned().to_string();
let sun_r = (parsed["sys"]["sunrise"].to_owned().as_f64().unwrap()) as u64;
let sun_s = (parsed["sys"]["sunset"].to_owned().as_f64().unwrap()) as u64;
temp_d
.set_attribute("style", "display: block")
.expect("failed to set attr style");
city.set_inner_html(&place);
image.set_inner_html(&content);
weather.set_inner_html(&parsed["weather"][0]["main"].to_owned().to_string());
pressure.set_inner_html(&([p, " hpa"].concat()));
humidity.set_inner_html(&([h, "%"].concat()));
sunrise.set_inner_html(&get_time(sun_r));
sunset.set_inner_html(&get_time(sun_s));
geo.set_inner_html(&(["[", &lon.to_string(), ",", &lat.to_string(), "]"].concat()));
});
});
// 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 {
let div = document.create_element("div").unwrap();
div.set_id(id);
div.set_class_name(class);
div
}
fn create_submit_box(document: &Document) -> Element {
let submit_box: Element = document.create_element("input").unwrap();
submit_box
.set_attribute("type", "button")
.expect("failed to set attr type to button");
submit_box
.set_attribute("value", "Search")
.expect("failed to set attr value to Search");
submit_box
.set_attribute("name", "submit")
.expect("failed to set attr name to submit");
submit_box.set_id("submit");
submit_box.set_class_name(" ReportStyles-bootstrapButton btn btn-info");
submit_box
}
fn create_input_box(document: &Document) -> Element {
let input_box = document.create_element("input").unwrap();
input_box
.set_attribute("name", "name")
.expect("failed to set attr name to name");
input_box.set_attribute("value", "Delhi").expect(
"
failed to set attr value to Delhi",
);
input_box
.set_attribute("type", "text")
.expect("failed to set attr type to text");
input_box
.set_attribute("placeholder", "Type city name here")
.expect("Failed to set attr placeholder to Type city name here");
input_box.set_id("name");
input_box.set_class_name("ReportStyles-search");
input_box
}
// 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 url = [url1, location, url2].concat();
let resp = reqwest::get(&url).await.unwrap().text().await.unwrap();
json::parse(&resp).unwrap()
}
// Convert millisecond into UTC date
fn get_time(millis: u64) -> String {
let d = UNIX_EPOCH + Duration::from_secs(millis);
// Create DateTime from SystemTime
let datetime = DateTime::<Utc>::from(d);
// Formats the combined date and time with the specified format string.
datetime.format("%H:%M:%S").to_string()
}
}