AngleSharp is a .NET library that gives you the ability to parse angle bracket based hyper-texts like HTML, SVG, and MathML. XML without validation is also supported by the library. An important aspect of AngleSharp is that CSS can also be parsed. The parser is built upon the official W3C specification. This produces a perfectly portable HTML5 DOM representation of the given source code. Also current features such as querySelector or querySelectorAll work for tree traversal.
The advantage over similar libraries like the HtmlAgilityPack is that e.g. CSS (including selectors) is already built-in. Also the parser uses the HTML 5.1 specification, which defines error handling and element correction. The AngleSharp library focuses on standards complience, interactivity and extensibility. It is therefore giving web developers, who are working with C#, all possibilities as they know from using the DOM in any modern browser.
The performance of AngleSharp is quite close to the performance of browsers. Even very large pages can be processed within milliseconds. AngleSharp tries to minimize memory allocations and reuses elements internally to avoid unnecessary object creation.
AngleSharp has been created as a PCL (profile 259) that supports a wide range of platforms. The list includes, but is not limited to:
- .NET Framework 4.5
- Silverlight 5
- Windows 8
- Windows Phone 8.1 / Windows Phone Silverlight
- Xamarin.Android
- Xamarin.iOS
Additionally the NuGet package also comes with support for the following platforms:
- Silverlight 5
- .NET 4.0
Please note, however, that those platforms have requirements (Microsoft.Bcl.Async), which are not needed by the platforms targeted from the original PCL version.
The simple example will use the website of Wikipedia for data retrieval.
// Setup the configuration to support document loading
var config = Configuration.Default.WithDefaultLoader();
// Load the names of all The Big Bang Theory episodes from Wikipedia
var address = "http://en.wikipedia.org/wiki/List_of_The_Big_Bang_Theory_episodes";
// Asynchronously get the document in a new context using the configuration
var document = await BrowsingContext.New(config).OpenAsync(address);
// This CSS selector gets the desired content
var cellSelector = "tr.vevent td:nth-child(3)";
// Perform the query to get all cells with the content
var cells = document.QuerySelectorAll(cellSelector);
// We are only interested in the text - select it with LINQ
var titles = cells.Select(m => m.TextContent);Every collection in AngleSharp supports LINQ statements. AngleSharp also provides many useful extension methods for element collections that cannot be found in the official DOM.
Documentation is available in form of the public Wiki here at GitHub.
The project's timeline, upcoming implementations, (currently) missing features and milestones is published and maintained in the Wiki as well. Issues should be reported on the GitHub's project page.
More information is also available by following some of the hyper references mentioned in the Wiki. In-depth articles will be published on the CodeProject, with links being placed in the Wiki at GitHub.
The project aims to bring a solid implementation of the W3C DOM for HTML, SVG, MathML and CSS to the CLR, written in C#. The idea is that you can basically do everything with the DOM in C# that you can do in JavaScript.
Most parts of the DOM are included, even though some may still miss their (right) implementation. The goal for v1.0 is to have almost everything implemented according to the official W3C specification (with useful extensions by the WHATWG).
The API is close to the DOM4 specification, however, the naming has been adjusted to apply with .NET conventions. Nevertheless, to make AngleSharp really useful for, e.g., a JavaScript engine, attributes have been placed on the corresponding interfaces (and methods, properties, ...) to indicate the status of the field in the official specification. This allows automatic generation of DOM objects with the official API.
This is a long-term project which will eventually result in a state of the art parser for the most important angle bracket based hyper-texts (and related description languages like CSS).
A more detailed change log can be found in the wiki.
0.8.0
- New CSS value model integrated
- PseudoElement available
- Mutation records connected
- Encoding basically finished
- Memory leak fixed
- All CSS4 selectors (excluding
||) included - Finished
Urlimplementation - HTML5 form validation
- Media features and CSS properties extended
- Namespace naming fix
- All HTML5 input types are supported
0.7.0
- Native (callback based) async parsing
- Interfaces for resource loading defined
- Browsing context available / creation possible (if demanded)
- Event model included (
addEventListener, ...) - CSS property / value architecture finalized
- Sample JavaScript engine based on Jint included
0.6.0:
- Implemented parsing of CSS media queries
- Improved URL parsing according to RFC 3986
- 100% finished HTML5 parser
- 98% finished CSS3 parser
- CSS properties and values defined and implemented
- CSS model implemented (i.e. getComputedStyle works)
- Tree traversal included (
NodeIteratorandTreeWalker) - Configuration model changed
- API changed (now interface driven)
- New source management for better handling and performance
0.5.0:
- Major API changes (DI is now the only singleton)
- 98% finished HTML5 parser
- 95% finished CSS3 parser
- 85% finished HTML DOM
- Included
Submit()method for forms
0.4.0:
- Final alpha version
- 98% finished HTML5 parser
- 90% finished CSS3 parser
- 85% finished HTML DOM
- Removed XML parser (until HTML and CSS are finished)
- Included WebRequester
0.3.0:
- Alpha version
- 95% finished HTML5 parser
- 90% finished CSS3 parser
- 85% finished HTML DOM
- Includes non-validating XML parser
- QuerySelectors etc. are fully working
- DOMAttribute applied where possible
0.2.0:
- First released version (pre-alpha)
- 95% finished HTML5 parser
- 70% finished CSS3 parser
- 80% finished HTML DOM
- SVG and MathML DOM are not implemented yet
- Performance seems to be quite OK
The roadmap presents a draft on what is about to be implemented, and when. The priorities might change, which will affect the roadmap. Additionally the implementation speed will be impacted by factors like people participating in the project and design decisions.
The time estimates are speculative, which means that the project could be totally off those predictions. Finding talented (and motivated) collaborators would certainly speed up the project.
(July 2015) 0.9.0
- (Simple?) XPath query support
- Interface for rendering defined
- CSS layout box
- Improved DOM algorithms and performance
- Parser token output
- More neat helpers
- CSS computation works with everything
- MathML support improved
- ShadowDOM
- AngleSharp.Scripting with generated JS bindings
(October 2015) 1.0.0
- Final release of the first version
- MathML and SVG finalized (for HTML)
- HTML5 parser at 100% with complete DOM
- SVG document included
- SVG DOM skeleton implemented
- Most important SVG elements implemented
The current schedule seems to be rather defensive, which does not mean the project will be "finished", i.e. released in version 1.0.0, before the given date. If there is time left, more unit tests will be written and the general code quality will be increased.
- Parsing HTML (incl. fragments)
- Parsing CSS (incl. selectors, declarations, ...)
- Constructing HTML (e.g., view-engine)
- Minifying CSS, HTML
- Querying document elements
- Crawling information
- Gathering statistics
- Connection to page analytics
- HTML / DOM Unit Tests
- Automated JavaScript interaction
- Testing other script engines
- ...
If you know some feature that AngleSharp is currently missing, and you are willing to implement the feature, then your contribution is more than welcome! Also if you have a really cool idea - do not be shy, we'd like to hear it.
If you have an idea how to improve the API (or what is missing) then posts / messages are also welcome. For instance there have been ongoing discussions about some styles that have been used by AngleSharp (e.g. HTMLDocument instead of HtmlDocument) in the past. In the end AngleSharp stopped using HTMLDocument (at least visible outside of the library). Now AngleSharp uses names like IDocument, IHtmlElement and so on. This change would not have been possible without fruitful discussions.
The project is always searching for additional contributors. Even if you do not have any code to contribute, but rather an idea for improvement, a bug report or a mistake in the documentation. These are the contributions that keep this project active.
Copyright (c) 2013-2015, Florian Rappl and collaborators. All rights reserved.
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