fix(core) Fix HTML encoding in webview rendered via data url

core/tauri-runtime-wry/Cargo.toml

@@ -21,6 +21,7 @@ rand = "0.8"
 raw-window-handle = "0.5"
 tracing = { version = "0.1", optional = true }
 arboard = { version = "3", optional = true }
+percent-encoding = "2.1"
 
 [target."cfg(windows)".dependencies]
 webview2-com = "0.19.1"
@@ -32,7 +33,6 @@ webview2-com = "0.19.1"
 [target."cfg(any(target_os = \"linux\", target_os = \"dragonfly\", target_os = \"freebsd\", target_os = \"openbsd\", target_os = \"netbsd\"))".dependencies]
 gtk = { version = "0.15", features = [ "v3_20" ] }
 webkit2gtk = { version = "0.18.2", features = [ "v2_22" ] }
-percent-encoding = "2.1"
 
 [target."cfg(any(target_os = \"ios\", target_os = \"macos\"))".dependencies]
 cocoa = "0.24"

core/tauri-runtime-wry/src/lib.rs

@@ -3247,13 +3247,27 @@ fn create_webview<T: UserEvent>(
  if window_builder.center {
  let _ = center_window(&window, window.inner_size());
  }
- let mut webview_builder = WebViewBuilder::new(window)
- .map_err(|e| Error::CreateWebview(Box::new(e)))?
+
+ let mut webview_builder =
+ WebViewBuilder::new(window).map_err(|e| Error::CreateWebview(Box::new(e)))?;
+
+ // use with_html method if html content can be extracted from url.
+ // else defaults to with_url method
+ webview_builder = if let Some(html_string) = tauri_utils::html::extract_html_content(&url) {
+ webview_builder
+ .with_html(html_string)
+ .map_err(|e| Error::CreateWebview(Box::new(e)))?
+ } else {
+ webview_builder
+ .with_url(&url)
+ .map_err(|e| Error::CreateWebview(Box::new(e)))?
+ };
+
+ webview_builder = webview_builder
  .with_focused(focused)
- .with_url(&url)
- .unwrap() // safe to unwrap because we validate the URL beforehand
  .with_transparent(is_window_transparent)
  .with_accept_first_mouse(webview_attributes.accept_first_mouse);
+
  if webview_attributes.file_drop_handler_enabled {
  webview_builder = webview_builder
  .with_file_drop_handler(create_file_drop_handler(window_event_listeners.clone()));

core/tauri-runtime/Cargo.toml

@@ -50,3 +50,4 @@ system-tray = [ ]
 macos-private-api = [ ]
 global-shortcut = [ ]
 clipboard = [ ]
+window-data-url = [ "tauri-utils/window-data-url" ]

core/tauri-utils/Cargo.toml

@@ -38,6 +38,7 @@ semver = "1"
 infer = "0.13"
 dunce = "1"
 log = "0.4.20"
+data-url = { version = "0.3.1", optional = true }
 
 [target."cfg(target_os = \"linux\")".dependencies]
 heck = "0.4"
@@ -54,3 +55,4 @@ process-relaunch-dangerous-allow-symlink-macos = [ ]
 config-json5 = [ "json5" ]
 config-toml = [ "toml" ]
 resources = [ "glob", "walkdir" ]
+window-data-url = [ "data-url" ]

core/tauri-utils/src/config.rs

@@ -54,12 +54,18 @@ pub enum WindowUrl {
  /// For instance, to load `tauri://localhost/users/john`,
  /// you can simply provide `users/john` in this configuration.
  App(PathBuf),
+ #[cfg(feature = "window-data-url")]
+ /// A data url, for example data:text/html,<h1>Hello world</h1>
+ /// Data url should not be encoded
+ DataUrl(Url),
 }
 
 impl fmt::Display for WindowUrl {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  match self {
  Self::External(url) => write!(f, "{url}"),
+ #[cfg(feature = "window-data-url")]
+ Self::DataUrl(url) => write!(f, "{url}"),
  Self::App(path) => write!(f, "{}", path.display()),
  }
  }
@@ -3281,6 +3287,11 @@ mod build {
  let url = url_lit(url);
  quote! { #prefix::External(#url) }
  }
+ #[cfg(feature = "window-data-url")]
+ Self::DataUrl(url) => {
+ let url = url_lit(url);
+ quote! { #prefix::DataUrl(#url) }
+ }
  })
  }
  }

core/tauri-utils/src/html.rs

@@ -286,6 +286,20 @@ pub fn inline_isolation(document: &mut NodeRef, dir: &Path) {
  }
 }
 
+/// Temporary naive method to check if a string is a html
+pub fn is_html(data_string: &str) -> bool {
+ data_string.contains('<') && data_string.contains('>')
+}
+
+/// Temporary naive method to extract data from html data string
+pub fn extract_html_content(input: &str) -> Option<&str> {
+ if input.starts_with("data:text/html,") {
+ Some(&input[15..])
+ } else {
+ None
+ }
+}
+
 #[cfg(test)]
 mod tests {
  use kuchiki::traits::*;

core/tauri/Cargo.toml

@@ -87,7 +87,7 @@ time = { version = "0.3", features = [ "parsing", "formatting" ], optional = tru
 os_info = { version = "3", optional = true }
 regex = { version = "1", optional = true }
 glob = "0.3"
-data-url = { version = "0.2", optional = true }
+data-url = { version = "0.3.1", optional = true }
 serialize-to-javascript = "=0.1.1"
 infer = { version = "0.9", optional = true }
 png = { version = "0.17", optional = true }
@@ -184,7 +184,7 @@ macos-private-api = [
  "tauri-runtime-wry/macos-private-api"
 ]
 windows7-compat = [ "win7-notifications" ]
-window-data-url = [ "data-url" ]
+window-data-url = [ "tauri-utils/window-data-url", "data-url" ]
 api-all = [
  "clipboard-all",
  "dialog-all",

core/tauri/src/manager.rs

@@ -995,6 +995,8 @@ impl<R: Runtime> WindowManager<R> {
  }
  }
  WindowUrl::External(url) => url.clone(),
+ #[cfg(feature = "window-data-url")]
+ WindowUrl::DataUrl(url) => url.clone(),
  _ => unimplemented!(),
  };
 
@@ -1005,23 +1007,46 @@ impl<R: Runtime> WindowManager<R> {
  ));
  }
 
- #[cfg(feature = "window-data-url")]
- if let Some(csp) = self.csp() {
- if url.scheme() == "data" {
- if let Ok(data_url) = data_url::DataUrl::process(url.as_str()) {
- let (body, _) = data_url.decode_to_vec().unwrap();
- let html = String::from_utf8_lossy(&body).into_owned();
- // naive way to check if it's an html
- if html.contains('<') && html.contains('>') {
+ match (
+ url.scheme(),
+ tauri_utils::html::extract_html_content(url.as_str()),
+ ) {
+ #[cfg(feature = "window-data-url")]
+ ("data", Some(html_string)) => {
+ // There is an issue with the external DataUrl where HTML containing special characters
+ // are not correctly processed. A workaround is to first percent encode the html string,
+ // before it processed by DataUrl.
+ let encoded_string = percent_encoding::utf8_percent_encode(html_string, percent_encoding::NON_ALPHANUMERIC).to_string();
+ let url = data_url::DataUrl::process(&format!("data:text/html,{}", encoded_string))
+ .map_err(|_| crate::Error::InvalidWindowUrl("Failed to process data url"))
+ .and_then(|data_url| {
+ data_url
+ .decode_to_vec()
+ .map_err(|_| crate::Error::InvalidWindowUrl("Failed to decode processed data url"))
+ })
+ .and_then(|(body, _)| {
+ let html = String::from_utf8_lossy(&body).into_owned();
  let mut document = tauri_utils::html::parse(html);
- tauri_utils::html::inject_csp(&mut document, &csp.to_string());
- url.set_path(&format!("text/html,{}", document.to_string()));
- }
- }
+ if let Some(csp) = self.csp() {
+ tauri_utils::html::inject_csp(&mut document, &csp.to_string());
+ }
+ // decode back to raw html, as the content should be fully decoded
+ // when passing to wry / tauri-runtime-wry, which will be responsible
+ // for handling the encoding based on the OS.
+ let encoded_html = document.to_string();
+ Ok(
+ percent_encoding::percent_decode_str(encoded_html.as_str())
+ .decode_utf8_lossy()
+ .to_string(),
+ )
+ })
+ .unwrap_or(html_string.to_string());
+ pending.url = format!("data:text/html,{}", url);
  }
- }
-
- pending.url = url.to_string();
+ _ => {
+ pending.url = url.to_string();
+ }
+ };
 
  if !pending.window_builder.has_icon() {
  if let Some(default_window_icon) = self.inner.default_window_icon.clone() {