Crate soup[−][src]
Inspired by the Python library “BeautifulSoup,” soup
is a layer on top of
html5ever
that aims to provide a slightly different API for querying &
manipulating HTML
Examples (inspired by bs4’s docs)
Here is the HTML document we will be using for the rest of the examples:
const THREE_SISTERS: &'static str = r#" <html><head><title>The Dormouse's story</title></head> <body> <p class="title"><b>The Dormouse's story</b></p> <p class="story">Once upon a time there were three little sisters; and their names were <a href="http://example.com/elsie" class="sister" id="link1">Elsie</a>, <a href="http://example.com/lacie" class="sister" id="link2">Lacie</a> and <a href="http://example.com/tillie" class="sister" id="link3">Tillie</a>; and they lived at the bottom of a well.</p> <p class="story">...</p> "#;
First let’s try searching for a tag with a specific name:
use soup::prelude::*; let soup = Soup::new(THREE_SISTERS); let title = soup.tag("title").find().expect("Couldn't find tag 'title'"); assert_eq!(title.display(), "<title>The Dormouse's story</title>"); assert_eq!(title.name(), "title"); assert_eq!(title.text(), "The Dormouse's story".to_string()); assert_eq!(title.parent().expect("Couldn't find parent of 'title'").name(), "head"); let p = soup.tag("p").find().expect("Couldn't find tag 'p'"); assert_eq!( p.display(), r#"<p class="title"><b>The Dormouse's story</b></p>"# ); assert_eq!(p.get("class"), Some("title".to_string()));
So we see that .find
will give us the first element that matches the query, and we’ve seen some
of the methods that we can call on the results. But what if we want to retrieve more than one
element with the query? For that, we’ll use .find_all
:
// .find returns only the first 'a' tag let a = soup.tag("a").find().expect("Couldn't find tag 'a'"); assert_eq!( a.display(), r#"<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>"# ); // but .find_all will return _all_ of them: let a_s = soup.tag("a").find_all(); assert_eq!( a_s.map(|a| a.display()) .collect::<Vec<_>>() .join("\n"), r#"<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a> <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a> <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>"# );
Since .find_all
returns an iterator, you can use it with all the methods you would
use with other iterators:
let expected = [ "http://example.com/elsie", "http://example.com/lacie", "http://example.com/tillie", ]; for (i, link) in soup.tag("a").find_all().enumerate() { let href = link.get("href").expect("Couldn't find link with 'href' attribute"); assert_eq!(href, expected[i].to_string()); }
The top-level structure we’ve been working with here, soup
, implements the same methods
that the query results do, so you can call the same methods on it and it will delegate the
calls to the root node:
let text = soup.text(); assert_eq!( text, r#"The Dormouse's story The Dormouse's story Once upon a time there were three little sisters; and their names were Elsie, Lacie and Tillie; and they lived at the bottom of a well. ... "# );
You can use more than just strings to search for results, such as Regex:
use regex::Regex; let soup = Soup::new(r#"<body><p>some text, <b>Some bold text</b></p></body>"#); let results = soup.tag(Regex::new("^b")?) .find_all() .map(|tag| tag.name().to_string()) .collect::<Vec<_>>(); assert_eq!(results, vec!["body".to_string(), "b".to_string()]);
Passing true
will match everything:
let soup = Soup::new(r#"<body><p>some text, <b>Some bold text</b></p></body>"#); let results = soup.tag(true) .find_all() .map(|tag| tag.name().to_string()) .collect::<Vec<_>>(); assert_eq!(results, vec![ "html".to_string(), "head".to_string(), "body".to_string(), "p".to_string(), "b".to_string(), ]);
(also, passing false
will always return no results, though if that is useful to you, please let me know)
So what can you do once you get the result of a query? Well, for one thing, you can traverse the tree a few different ways. You can ascend the tree:
let soup = Soup::new(r#"<body><p>some text, <b>Some bold text</b></p></body>"#); let b = soup.tag("b") .find() .expect("Couldn't find tag 'b'"); let p = b.parent() .expect("Couldn't find parent of 'b'"); assert_eq!(p.name(), "p".to_string()); let body = p.parent() .expect("Couldn't find parent of 'p'"); assert_eq!(body.name(), "body".to_string());
Or you can descend it:
let soup = Soup::new(r#"<body><ul><li>ONE</li><li>TWO</li><li>THREE</li></ul></body>"#); let ul = soup.tag("ul") .find() .expect("Couldn't find tag 'ul'"); let mut li_tags = ul.children().filter(|child| child.is_element()); assert_eq!(li_tags.next().map(|tag| tag.text().to_string()), Some("ONE".to_string())); assert_eq!(li_tags.next().map(|tag| tag.text().to_string()), Some("TWO".to_string())); assert_eq!(li_tags.next().map(|tag| tag.text().to_string()), Some("THREE".to_string())); assert!(li_tags.next().is_none());
Or ascend it with an iterator:
let soup = Soup::new(r#"<body><ul><li>ONE</li><li>TWO</li><li>THREE</li></ul></body>"#); let li = soup.tag("li").find().expect("Couldn't find tag 'li'"); let mut parents = li.parents(); assert_eq!(parents.next().map(|tag| tag.name().to_string()), Some("ul".to_string())); assert_eq!(parents.next().map(|tag| tag.name().to_string()), Some("body".to_string())); assert_eq!(parents.next().map(|tag| tag.name().to_string()), Some("html".to_string())); assert_eq!(parents.next().map(|tag| tag.name().to_string()), Some("[document]".to_string()));
Modules
pattern | Traits & impls for matching types with strings |
prelude | This module exports all the important types & traits to use |
Structs
QueryBuilder | Construct a query to apply to an HTML tree |
Soup | Parses HTML & provides methods to query & manipulate the document |
Traits
NodeExt | Adds some convenience methods to the |
QueryBuilderExt | Adds the QueryBuilder constructor methods to the implementing type |