Refactor the support for making browsers download files, and use more widely

Cargo.lock

@@ -23,12 +23,14 @@ dependencies = [
  "futures-channel",
  "include_dir",
  "instant",
+ "js-sys",
  "lazy_static",
  "log",
  "reqwest",
  "serde",
  "serde_json",
  "tokio",
+ "wasm-bindgen",
  "web-sys",
 ]
 
@@ -2101,12 +2103,10 @@ dependencies = [
  "anyhow",
  "contour",
  "flate2",
- "fs-err",
  "geo",
  "geojson",
  "geom",
  "getrandom",
- "js-sys",
  "lazy_static",
  "log",
  "map_gui",
@@ -2119,7 +2119,6 @@ dependencies = [
  "structopt",
  "synthpop",
  "wasm-bindgen",
- "web-sys",
  "widgetry",
 ]
 
@@ -3508,7 +3507,6 @@ dependencies = [
  "ctrlc",
  "downcast-rs",
  "enum_dispatch",
- "fs-err",
  "geom",
  "instant",
  "libm 0.2.1",

abstio/Cargo.toml

@@ -23,4 +23,6 @@ tokio = "1.1.1"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 include_dir = { git = "https://github.com/dabreegster/include_dir", branch = "union" }
-web-sys = { version = "0.3.47", features=["Storage", "Window"] }
+js-sys = "0.3.47"
+wasm-bindgen = "0.2.70"
+web-sys = { version = "0.3.47", features=["HtmlElement", "Storage", "Window"] }

abstio/src/io_native.rs

@@ -198,3 +198,10 @@ impl Read for FileWithProgress {
         Ok(bytes)
     }
 }
+
+/// Returns path on success
+pub fn write_file(path: String, contents: String) -> Result<String> {
+    let mut file = File::create(&path)?;
+    write!(file, "{}", contents)?;
+    Ok(path)
+}

abstio/src/io_web.rs

@@ -179,3 +179,29 @@ fn list_local_storage_keys() -> Vec<String> {
     }
     keys
 }
+
+/// Returns path on success
+pub fn write_file(path: String, contents: String) -> Result<String> {
+    // Make the browser prompt the user to save a local file with arbitrary contents.
+    use wasm_bindgen::JsCast;
+
+    let data: String = js_sys::JsString::from("data:text/json;charset=utf-8,")
+        .concat(&js_sys::encode_uri_component(&contents))
+        .into();
+
+    // TODO Proper error handling
+    let window = web_sys::window().unwrap();
+    let document = window.document().unwrap();
+    let node = document
+        .create_element("a")
+        .unwrap()
+        .dyn_into::<web_sys::HtmlElement>()
+        .unwrap();
+    node.set_attribute("href", &data).unwrap();
+    node.set_attribute("download", &path).unwrap();
+    document.body().unwrap().append_child(&node).unwrap();
+    node.click();
+    node.remove();
+
+    Ok(path)
+}

apps/game/src/layer/traffic.rs

@@ -234,11 +234,7 @@ impl Throughput {
             )
             .flex_wrap(ctx, Percent::int(20)),
             ColorLegend::gradient(ctx, &app.cs.good_to_bad_red, vec!["0", "highest"]),
-            if cfg!(not(target_arch = "wasm32")) {
-                ctx.style().btn_plain.text("Export to CSV").build_def(ctx)
-            } else {
-                Widget::nothing()
-            },
+            ctx.style().btn_plain.text("Export to CSV").build_def(ctx),
         ]))
         .aligned_pair(PANEL_PLACEMENT)
         .build(ctx);
@@ -758,22 +754,28 @@ fn export_throughput(app: &App) -> Result<(String, String)> {
         app.primary.map.get_name().as_filename(),
         app.primary.sim.time().as_filename()
     );
-    app.primary
-        .sim
-        .get_analytics()
-        .road_thruput
-        .export_csv(&path1, |id| id.0)?;
+    let path1 = abstio::write_file(
+        path1,
+        app.primary
+            .sim
+            .get_analytics()
+            .road_thruput
+            .export_csv(|id| id.0),
+    )?;
 
     let path2 = format!(
         "intersection_throughput_{}_{}.csv",
         app.primary.map.get_name().as_filename(),
         app.primary.sim.time().as_filename()
     );
-    app.primary
-        .sim
-        .get_analytics()
-        .intersection_thruput
-        .export_csv(&path2, |id| id.0)?;
+    let path2 = abstio::write_file(
+        path2,
+        app.primary
+            .sim
+            .get_analytics()
+            .intersection_thruput
+            .export_csv(|id| id.0),
+    )?;
 
     Ok((path1, path2))
 }

apps/game/src/sandbox/dashboards/risks.rs

@@ -1,8 +1,7 @@
 use std::collections::BTreeSet;
-use std::io::Write;
+use std::fmt::Write;
 
 use anyhow::Result;
-use fs_err::File;
 
 use abstutil::prettyprint_usize;
 use sim::{ProblemType, TripID};
@@ -207,9 +206,9 @@ fn export_problems(app: &App) -> Result<String> {
         app.primary.map.get_name().as_filename(),
         app.primary.sim.time().as_filename()
     );
-    let mut f = File::create(&path)?;
+    let mut out = String::new();
     writeln!(
-        f,
+        out,
         "id,mode,seconds_after,problem_type,problems_before,problems_after"
     )?;
 
@@ -225,7 +224,7 @@ fn export_problems(app: &App) -> Result<String> {
                 problem_type.count(after.problems_per_trip.get(&id).unwrap_or(&empty));
             if count_before != 0 || count_after != 0 {
                 writeln!(
-                    f,
+                    out,
                     "{},{:?},{},{:?},{},{}",
                     id.0,
                     mode,
@@ -238,5 +237,5 @@ fn export_problems(app: &App) -> Result<String> {
         }
     }
 
-    Ok(path)
+    abstio::write_file(path, out)
 }

apps/game/src/sandbox/dashboards/travel_times.rs

@@ -1,8 +1,7 @@
 use std::collections::BTreeSet;
-use std::io::Write;
+use std::fmt::Write;
 
 use anyhow::Result;
-use fs_err::File;
 
 use abstutil::prettyprint_usize;
 use geom::{Distance, Duration, Polygon, Pt2D};
@@ -42,16 +41,13 @@ impl TravelTimes {
             ));
         }
 
-        // TODO We can make file downloads of dynamically generated data work on the browser too...
-        if cfg!(not(target_arch = "wasm32")) {
-            filters.push(
-                ctx.style()
-                    .btn_plain
-                    .text("Export to CSV")
-                    .build_def(ctx)
-                    .align_bottom(),
-            );
-        }
+        filters.push(
+            ctx.style()
+                .btn_plain
+                .text("Export to CSV")
+                .build_def(ctx)
+                .align_bottom(),
+        );
 
         Panel::new_builder(Widget::col(vec![
             DashTab::TravelTimes.picker(ctx, app),
@@ -645,8 +641,8 @@ fn export_times(app: &App) -> Result<String> {
         app.primary.map.get_name().as_filename(),
         app.primary.sim.time().as_filename()
     );
-    let mut f = File::create(&path)?;
-    writeln!(f, "id,mode,seconds_before,seconds_after")?;
+    let mut out = String::new();
+    writeln!(out, "id,mode,seconds_before,seconds_after")?;
     for (id, b, a, mode) in app
         .primary
         .sim
@@ -654,7 +650,7 @@ fn export_times(app: &App) -> Result<String> {
         .both_finished_trips(app.primary.sim.time(), app.prebaked())
     {
         writeln!(
-            f,
+            out,
             "{},{:?},{},{}",
             id.0,
             mode,
@@ -662,5 +658,5 @@ fn export_times(app: &App) -> Result<String> {
             a.inner_seconds()
         )?;
     }
-    Ok(path)
+    abstio::write_file(path, out)
 }

apps/ltn/Cargo.toml

@@ -9,7 +9,7 @@ crate-type = ["cdylib", "lib"]
 
 [features]
 default = ["map_gui/native", "widgetry/native-backend"]
-wasm = ["getrandom/js", "js-sys", "map_gui/wasm", "wasm-bindgen", "web-sys", "widgetry/wasm-backend"]
+wasm = ["getrandom/js", "map_gui/wasm", "wasm-bindgen", "widgetry/wasm-backend"]
 
 [dependencies]
 abstio = { path = "../../abstio" }
@@ -17,12 +17,10 @@ abstutil = { path = "../../abstutil" }
 anyhow = "1.0.38"
 contour = "0.4.0"
 flate2 = "1.0.20"
-fs-err = "2.6.0"
 geo = "0.20.1"
 geojson = { version = "0.22.2", features = ["geo-types"] }
 geom = { path = "../../geom" }
 getrandom = { version = "0.2.3", optional = true }
-js-sys = { version = "0.3.47", optional = true }
 lazy_static = "1.4.0"
 log = "0.4"
 maplit = "1.0.2"
@@ -36,8 +34,3 @@ synthpop = { path = "../../synthpop" }
 wasm-bindgen = { version = "0.2.70", optional = true }
 widgetry = { path = "../../widgetry" }
 structopt = "0.3.23"
-
-[dependencies.web-sys]
-version = "0.3.47"
-optional = true
-features = ["HtmlElement"]

apps/ltn/src/export.rs

@@ -9,39 +9,7 @@ use crate::{App, Neighborhood};
 pub fn write_geojson_file(ctx: &EventCtx, app: &App) -> Result<String> {
     let contents = geojson_string(ctx, app)?;
     let path = format!("ltn_{}.geojson", app.map.get_name().map);
-
-    // TODO Refactor into map_gui or abstio and handle errors better
-    #[cfg(target_arch = "wasm32")]
-    {
-        use wasm_bindgen::JsCast;
-
-        let data: String = js_sys::JsString::from("data:text/json;charset=utf-8,")
-            .concat(&js_sys::encode_uri_component(&contents))
-            .into();
-
-        let window = web_sys::window().unwrap();
-        let document = window.document().unwrap();
-        let node = document
-            .create_element("a")
-            .unwrap()
-            .dyn_into::<web_sys::HtmlElement>()
-            .unwrap();
-        node.set_attribute("href", &data).unwrap();
-        node.set_attribute("download", &path).unwrap();
-        document.body().unwrap().append_child(&node).unwrap();
-        node.click();
-        node.remove();
-    }
-
-    #[cfg(not(target_arch = "wasm32"))]
-    {
-        use std::io::Write;
-
-        let mut file = fs_err::File::create(&path)?;
-        write!(file, "{}", contents)?;
-    }
-
-    Ok(path)
+    abstio::write_file(path, contents)
 }
 
 fn geojson_string(ctx: &EventCtx, app: &App) -> Result<String> {

sim/Cargo.toml

@@ -11,7 +11,6 @@ anyhow = "1.0.38"
 ctrlc = { version = "3.1.7", optional = true }
 downcast-rs = "1.2.0"
 enum_dispatch = "0.3.5"
-fs-err = "2.6.0"
 geom = { path = "../geom" }
 instant = "0.1.7"
 libm = "0.2.1"

sim/src/analytics.rs

@@ -1,8 +1,6 @@
 use std::collections::{BTreeMap, BTreeSet, VecDeque};
-use std::io::Write;
+use std::fmt::Write;
 
-use anyhow::Result;
-use fs_err::File;
 use serde::{Deserialize, Serialize};
 
 use abstutil::Counter;
@@ -834,13 +832,22 @@ impl<X: Ord + Clone> TimeSeriesCount<X> {
         pts_per_type.into_iter().collect()
     }
 
-    pub fn export_csv<F: Fn(&X) -> usize>(&self, path: &str, extract_id: F) -> Result<()> {
-        let mut f = File::create(path)?;
-        writeln!(f, "id,agent_type,hour,count")?;
+    /// Returns the contents of a CSV file
+    pub fn export_csv<F: Fn(&X) -> usize>(&self, extract_id: F) -> String {
+        let mut out = String::new();
+        writeln!(out, "id,agent_type,hour,count").unwrap();
         for ((id, agent_type, hour), count) in &self.counts {
-            writeln!(f, "{},{:?},{},{}", extract_id(id), agent_type, hour, count)?;
+            writeln!(
+                out,
+                "{},{:?},{},{}",
+                extract_id(id),
+                agent_type,
+                hour,
+                count
+            )
+            .unwrap();
         }
-        Ok(())
+        out
     }
 }