SmartReader is a .NET Standard 1.3 library to extract the main content of a web page, based on a port of the Readability library by Mozilla, which in turn is based on the famous original Readability library.
You can do it the standard way, by using the NuGet package.
PM> Install-Package SmartReader
There are already other similar good projects, but they don't support .NET Core and they are based on old version of Readability. The original library is already quite stable, but there are always improvement to be made. So by relying on a original library maintained by such a competent organization we can piggyback on their hard work and user base.
There are also some improvements: it returns an author and publication date, the language of the article, the featured image, a list of images and an indication of the time needed to read it.
Feel free to suggest new features.
There are mainly two ways to use the library. The first is by creating a new Reader object, with the URI as the argument, and then calling the GetArticle method to obtain the extracted Article. The second one is by using one of the static methods ParseArticle of Reader directly, to return an Article. Both ways are available also through an async method, called respectively GetArticleAsync and ParseArticleAsync.
The advantage of using an object, instead of the static method, is that it gives you the chance to set some options.
There is also the option to parse directly a String or Stream that you have obtained by some other way. This is available either with ParseArticle methods or by using the proper Reader constructor. In either case, you also need to give the original URI. It will not re-download the text, but it need the URI to make some checks and modifications on the links present on the page. If you cannot provide the original uri, you can use a fake one, like https:\\localhost.
If the extraction fails, the returned Article object will have the field IsReadable set to false.
The content of the article is unstyled, but it is wrapped in a div with the id readability-content that you can style yourself.
The library tries to detect the correct encoding of the text, if the correct tags are present in the text.
On the Article object you can call GetImagesAsync to obtain a Task for a list of Image objects, representing the images found in the extracted article. The method is async because it makes HEAD Requests, to obtain the size of the images and only returns the ones that are bigger then the specified size. The size by default is 75KB.
This is to exclude things such as images used in the UI.
Using the GetArticle method.
SmartReader.Reader sr = new SmartReader.Reader("https://arstechnica.co.uk/information-technology/2017/02/humans-must-become-cyborgs-to-survive-says-elon-musk/");
sr.Debug = true;
sr.Logger = new StringWriter();
SmartReader.Article article = sr.GetArticle();
var images = article.GetImagesAsync();
if(article.IsReadable)
{
// do something with it
}Using the ParseArticle static method.
SmartReader.Article article = SmartReader.Reader.ParseArticle("https://arstechnica.co.uk/information-technology/2017/02/humans-must-become-cyborgs-to-survive-says-elon-musk/");
if(article.IsReadable)
{
// do something with it
}intMaxElemsToParse
Max number of nodes supported by this parser.
Default: 0 (no limit)intNTopCandidates
The number of top candidates to consider when analyzing how tight the competition is among candidates.
Default: 5boolDebug
Set the Debug option. If set to true the library writes the data on Logger.
Default: falseTextWriterLogger
Where the debug data is going to be written.
Default: nullboolContinueIfNotReadable
The library tries to determine if it will find an article before actually trying to do it. This option decides whether to continue if the library heuristics fails. This value is ignored if Debug is set to true
Default: trueintWordThreshold
The minimum number of words an article must have in order to return a result.
Default: 500
UriUri
Original UriStringTitle
TitleStringByline
Byline of the article, usually containing author and publication dateStringDir
Direction of the textStringFeaturedImage
The main image of the articleStringContent
Html content of the articleStringTextContent
The pure text of the articleStringExcerpt
A summary of the article, based on metadata or first paragraphStringLanguage
Language string (es. 'en-US')intLength
Length of the text of the articleTimeSpanTimeToRead
Average time needed to read the articleDateTime?PublicationDate
Date of publication of the articleboolIsReadable
Indicate whether we successfully find an article
It's important to be aware that the fields Byline, Author and PublicationDate are found independently of each other. So there might be some inconsistencies and unexpected data. For instance, Byline may be a string in the form "@Date by @Author" or "@Author, @Date" or any other combination used by the publication.
The TimeToRead calculation is based on the research found in Standardized Assessment of Reading Performance: The New International Reading Speed Texts IReST. It should be accurate if the article is written in one of the languages in the research, but it is just an educated guess for the others languages.
The FeaturedImage property holds the image indicated by the Open Graph or Twitter meta tags. If neither of these is present, and you called the GetImagesAsync method, it will be set with the first image found.
The demo project is a simple ASP.NET Core webpage that allows you to input an address and see the results of the library.
The console project is a Console program that allows you to see the results of the library on a random test page.
In case you want to build the Nuget package yourself you cannot use the standard nuget pack because of a bug related to .NET Core. Instaed use the dotnet pack command.
dotnet pack --configuration Release --output "..\nupkgs"
The command must be issued inside the src/SmartReader folder, otherwise it will generate nuget packages for all projects.
The project uses the Apache License.
Thanks to all the people involved.