From 7de8132386600e4dcdc511092e71898261860b8d Mon Sep 17 00:00:00 2001
From: Nico Burns <nico@nicoburns.com>
Date: Mon, 29 Jul 2024 12:58:18 +1200
Subject: [PATCH] Implement fetching of local filesystem resources

---
 examples/markdown.rs     | 20 +++++++++++---
 packages/dom/src/util.rs | 57 +++++++++++++++++++++++++++++++++-------
 2 files changed, 63 insertions(+), 14 deletions(-)

diff --git a/examples/markdown.rs b/examples/markdown.rs
index 87c64294..b100705c 100644
--- a/examples/markdown.rs
+++ b/examples/markdown.rs
@@ -1,14 +1,26 @@
 //! Render the readme.md using the gpu renderer
 
+use std::path::Path;
+
 use comrak::{markdown_to_html, ExtensionOptionsBuilder, Options, RenderOptionsBuilder};
 use dioxus_blitz::Config;
 
 fn main() {
-    let contents = std::env::args()
+    let (base_url, contents) = std::env::args()
         .skip(1)
         .next()
-        .map(|path| std::fs::read_to_string(path).unwrap())
-        .unwrap_or(include_str!("../README.md").to_string());
+        .map(|path| {
+            let base_path = std::path::absolute(Path::new(&path)).unwrap();
+            let base_path = base_path.parent().unwrap().to_string_lossy();
+            let base_url = format!("file://{}/", base_path);
+            let contents = std::fs::read_to_string(path).unwrap();
+            (base_url, contents)
+        })
+        .unwrap_or({
+            let base_url = "https://raw.githubusercontent.com/DioxusLabs/blitz/main/".to_string();
+            let contents = include_str!("../README.md").to_string();
+            (base_url, contents)
+        });
 
     let stylesheet = include_str!("./assets/github-markdown-light.css");
     let body_html = markdown_to_html(
@@ -52,7 +64,7 @@ fn main() {
         &html,
         Config {
             stylesheets: vec![String::from(stylesheet)],
-            base_url: Some("https://raw.githubusercontent.com/DioxusLabs/blitz/main/".to_string()),
+            base_url: Some(base_url),
         },
     );
 }
diff --git a/packages/dom/src/util.rs b/packages/dom/src/util.rs
index 2e113520..60e87306 100644
--- a/packages/dom/src/util.rs
+++ b/packages/dom/src/util.rs
@@ -11,13 +11,42 @@ const FILE_SIZE_LIMIT: u64 = 1_000_000_000; // 1GB
 
 static FONT_DB: OnceLock<Arc<usvg::fontdb::Database>> = OnceLock::new();
 
-pub(crate) fn fetch_blob(url: &str) -> Result<Vec<u8>, Box<ureq::Error>> {
+pub(crate) enum FetchErr {
+    UrlParse(url::ParseError),
+    Ureq(Box<ureq::Error>),
+    FileIo(std::io::Error),
+}
+impl From<url::ParseError> for FetchErr {
+    fn from(value: url::ParseError) -> Self {
+        Self::UrlParse(value)
+    }
+}
+impl From<Box<ureq::Error>> for FetchErr {
+    fn from(value: Box<ureq::Error>) -> Self {
+        Self::Ureq(value)
+    }
+}
+impl From<std::io::Error> for FetchErr {
+    fn from(value: std::io::Error) -> Self {
+        Self::FileIo(value)
+    }
+}
+
+pub(crate) fn fetch_blob(url: &str) -> Result<Vec<u8>, FetchErr> {
+    // Handle data URIs
     if url.starts_with("data:") {
         let data_url = data_url::DataUrl::process(url).unwrap();
         let decoded = data_url.decode_to_vec().expect("Invalid data url");
         return Ok(decoded.0);
     }
 
+    // Handle file:// URLs
+    let parsed_url = Url::parse(url)?;
+    if parsed_url.scheme() == "file" {
+        let file_content = std::fs::read(parsed_url.path())?;
+        return Ok(file_content);
+    }
+
     let resp = ureq::get(url)
         .set("User-Agent", USER_AGENT)
         .call()
@@ -37,7 +66,7 @@ pub(crate) fn fetch_blob(url: &str) -> Result<Vec<u8>, Box<ureq::Error>> {
     Ok(bytes)
 }
 
-pub(crate) fn fetch_string(url: &str) -> Result<String, Box<ureq::Error>> {
+pub(crate) fn fetch_string(url: &str) -> Result<String, FetchErr> {
     fetch_blob(url).map(|vec| String::from_utf8(vec).expect("Invalid UTF8"))
 }
 
@@ -55,23 +84,30 @@ pub(crate) enum ImageOrSvg {
 
 #[allow(unused)]
 pub(crate) enum ImageFetchErr {
-    FetchErr(Box<ureq::Error>),
-    ImageError(image::error::ImageError),
-    SvgError(usvg::Error),
+    UrlParse(url::ParseError),
+    Ureq(Box<ureq::Error>),
+    FileIo(std::io::Error),
+    ImageParse(image::error::ImageError),
+    SvgParse(usvg::Error),
 }
-impl From<Box<ureq::Error>> for ImageFetchErr {
-    fn from(value: Box<ureq::Error>) -> Self {
-        Self::FetchErr(value)
+
+impl From<FetchErr> for ImageFetchErr {
+    fn from(value: FetchErr) -> Self {
+        match value {
+            FetchErr::UrlParse(err) => Self::UrlParse(err),
+            FetchErr::Ureq(err) => Self::Ureq(err),
+            FetchErr::FileIo(err) => Self::FileIo(err),
+        }
     }
 }
 impl From<image::error::ImageError> for ImageFetchErr {
     fn from(value: image::error::ImageError) -> Self {
-        Self::ImageError(value)
+        Self::ImageParse(value)
     }
 }
 impl From<usvg::Error> for ImageFetchErr {
     fn from(value: usvg::Error) -> Self {
-        Self::SvgError(value)
+        Self::SvgParse(value)
     }
 }
 
@@ -172,6 +208,7 @@ pub fn walk_tree(indent: usize, node: &Node) {
 
 use peniko::Color as PenikoColor;
 use style::color::AbsoluteColor;
+use url::Url;
 
 pub trait ToPenikoColor {
     fn as_peniko(&self) -> PenikoColor;