use std::collections::HashMap; use async_std::fs::File; use async_std::io::prelude::*; use async_std::task; use kuchiki::{traits::*, NodeRef}; use url::Url; use crate::moz_readability::{MetaData, Readability}; pub type ResourceInfo = (String, Option); lazy_static! { static ref ESC_SEQ_REGEX: regex::Regex = regex::Regex::new(r#"(&|<|>|'|")"#).unwrap(); } pub struct Extractor { article: Option, pub img_urls: Vec, readability: Readability, } impl Extractor { /// Create a new instance of an HTML extractor given an HTML string pub fn from_html(html_str: &str) -> Self { Extractor { article: None, img_urls: Vec::new(), readability: Readability::new(html_str), } } /// Locates and extracts the HTML in a document which is determined to be /// the source of the content pub fn extract_content(&mut self, url: &str) { self.readability.parse(url); if let Some(article_node_ref) = &self.readability.article_node { let template = r#" "#; let doc = kuchiki::parse_html().one(template); let body = doc.select_first("body").unwrap(); body.as_node().append(article_node_ref.clone()); self.article = Some(doc); } } /// Traverses the DOM tree of the content and retrieves the IMG URLs fn extract_img_urls(&mut self) { if let Some(content_ref) = &self.readability.article_node { for img_ref in content_ref.select("img").unwrap() { img_ref.as_node().as_element().map(|img_elem| { img_elem.attributes.borrow().get("src").map(|img_url| { if !(img_url.is_empty() || img_url.starts_with("data:image")) { self.img_urls.push((img_url.to_string(), None)) } }) }); } } } pub async fn download_images(&mut self, article_origin: &Url) -> async_std::io::Result<()> { let mut async_download_tasks = Vec::with_capacity(self.img_urls.len()); self.extract_img_urls(); if self.img_urls.len() > 0 { println!("Downloading images..."); } for img_url in &self.img_urls { let img_url = img_url.0.clone(); let abs_url = get_absolute_url(&img_url, article_origin); async_download_tasks.push(task::spawn(async move { let mut img_response = surf::Client::new() // The middleware has been temporarily commented out because it happens // to affect downloading images when there is no redirecting // .with(surf::middleware::Redirect::default()) .get(&abs_url) .await .expect("Unable to retrieve file"); let img_content: Vec = img_response.body_bytes().await.unwrap(); let img_mime = img_response .content_type() .map(|mime| mime.essence().to_string()); let img_ext = img_response .content_type() .map(|mime| map_mime_subtype_to_ext(mime.subtype()).to_string()) .unwrap(); let mut img_path = std::env::temp_dir(); img_path.push(format!("{}.{}", hash_url(&abs_url), &img_ext)); let mut img_file = File::create(&img_path) .await .expect("Unable to create file"); img_file .write_all(&img_content) .await .expect("Unable to save to file"); ( img_url, img_path .file_name() .map(|os_str_name| { os_str_name .to_str() .expect("Unable to get image file name") .to_string() }) .unwrap(), img_mime, ) })); } self.img_urls.clear(); for async_task in async_download_tasks { let (img_url, img_path, img_mime) = async_task.await; // Update the image sources let img_ref = self .readability .article_node .as_mut() .expect("Unable to get mutable ref") .select_first(&format!("img[src='{}']", img_url)) .expect("Image node does not exist"); let mut img_node = img_ref.attributes.borrow_mut(); *img_node.get_mut("src").unwrap() = img_path.clone(); // srcset is removed because readers such as Foliate then fail to display // the image already downloaded and stored in src img_node.remove("srcset"); self.img_urls.push((img_path, img_mime)); } Ok(()) } pub fn article(&self) -> Option<&NodeRef> { self.article.as_ref() } pub fn metadata(&self) -> &MetaData { &self.readability.metadata } } /// Utility for hashing URLs. This is used to help store files locally with unique values fn hash_url(url: &str) -> String { format!("{:x}", md5::compute(url.as_bytes())) } /// Handles getting the extension from a given MIME subtype. fn map_mime_subtype_to_ext(subtype: &str) -> &str { if subtype == ("svg+xml") { return "svg"; } else if subtype == "x-icon" { "ico" } else { subtype } } fn get_absolute_url(url: &str, request_url: &Url) -> String { if Url::parse(url).is_ok() { url.to_owned() } else if url.starts_with("/") { Url::parse(&format!( "{}://{}", request_url.scheme(), request_url.host_str().unwrap() )) .unwrap() .join(url) .unwrap() .into_string() } else { request_url.join(url).unwrap().into_string() } } /// Serializes a NodeRef to a string that is XHTML compatible /// The only DOM nodes serialized are Text and Element nodes pub fn serialize_to_xhtml( node_ref: &NodeRef, mut w: &mut W, ) -> Result<(), Box> { let mut escape_map = HashMap::new(); escape_map.insert("<", "<"); escape_map.insert(">", ">"); escape_map.insert("&", "&"); escape_map.insert("\"", """); escape_map.insert("'", "'"); for edge in node_ref.traverse_inclusive() { match edge { kuchiki::iter::NodeEdge::Start(n) => match n.data() { kuchiki::NodeData::Text(rc_text) => { let text = rc_text.borrow(); let esc_text = ESC_SEQ_REGEX .replace_all(&text, |captures: ®ex::Captures| escape_map[&captures[1]]); write!(&mut w, "{}", esc_text)?; } kuchiki::NodeData::Element(elem_data) => { let attrs = elem_data.attributes.borrow(); let attrs_str = attrs .map .iter() .map(|(k, v)| { format!( "{}=\"{}\"", k.local, ESC_SEQ_REGEX .replace_all(&v.value, |captures: ®ex::Captures| { escape_map[&captures[1]] }) ) }) .fold("".to_string(), |acc, val| acc + " " + &val); write!(&mut w, "<{}{}>", &elem_data.name.local, attrs_str)?; } _ => (), }, kuchiki::iter::NodeEdge::End(n) => match n.data() { kuchiki::NodeData::Element(elem_data) => { write!(&mut w, "", &elem_data.name.local)?; } _ => (), }, } } Ok(()) } #[cfg(test)] mod test { use super::*; const TEST_HTML: &'static str = r#" Testing Paperoni

Testing Paperoni

Starting out

Some Lorem Ipsum text here

Observe this picture

"#; #[test] fn test_extract_img_urls() { let mut extractor = Extractor::from_html(TEST_HTML); extractor.extract_content("http://example.com/"); extractor.extract_img_urls(); assert!(extractor.img_urls.len() > 0); assert_eq!( vec![("http://example.com/img.jpg".to_string(), None)], extractor.img_urls ); } #[test] fn test_map_mime_type_to_ext() { let mime_subtypes = vec![ "apng", "bmp", "gif", "x-icon", "jpeg", "png", "svg+xml", "tiff", "webp", ]; let exts = mime_subtypes .into_iter() .map(|mime_type| map_mime_subtype_to_ext(mime_type)) .collect::>(); assert_eq!( vec!["apng", "bmp", "gif", "ico", "jpeg", "png", "svg", "tiff", "webp"], exts ); } }