![]() The code still parses the HTML and converts it to a JSON object from the HackerNewsItems class, but the HTML is parsed after loading it into a virtual browser. ![]() ```c # private string ParseHtml( string html) Var linkList = ParseHtml(browser.PageSource) After installing Selenium, add the following using statements to your file:īinaryLocation = "C:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe" Selenium lets you pull HTML from a page using your browser executable, and then you can parse the HTML using the Agility Pack in the same way we did above.īefore you can parse in a browser, you need to install the Selenium.WebDriver from NuGet and add the using statements to the project. To emulate code loading in a browser, you can use a library named Selenium. Since client-side code executes after the browser loads HTML and scripts, the previous example will not get the results that you need. This is because some websites work with client-side code to render results. In some cases, you’ll need to use Selenium with a browser to pull HTML from a page. Pull HTML Using Selenium and a Chrome Browser Instance HTML Agility Pack will traverse down the DOM hierarchy using various methods should you want to pull table elements item by item down the DOM tree. Note that you can also select child nodes from parent nodes with the Agility Pack. Var response = client.GetStringAsync(fullUrl) ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls13 Ĭ() Private static async Task CallUrl( string fullUrl) Here is the full code from start to finish with the final JSON object contained in the linkList variable: That’s it - you’ve pulled the top 10 news links from Hacker News and created a JSON object. The last statement before the method return statement is Newtonsoft turning the generic list into a JSON object. Each HackerNewsItems object is then added to a generic list, which will contain all 10 items. Notice in the code above that the HackerNewsItems class is populated from the parsed HTML. String results = JsonConvert.SerializeObject(newsLinks) Var score = link.SelectSingleNode( item = new HackerNewsItems() ![]() We’ll create a class named HackerNewsItems to illustrate: You can create a class in the same namespace as you’ve been creating your code in the previous examples. The easiest way to create a JSON object is to serialize it from a class. Once we have a JSON object, we can then pass it to anything we want - another method in our code, an API on an external platform, or to another application that can ingest JSON. We now need to create a JSON object to contain the information. Var score = link.SelectSingleNode( above code iterates through all top 10 links on Hacker News and gets the information that we want, but it doesn’t do anything with the information. Var rank = link.SelectSingleNode( storyName = link.SelectSingleNode( url = link.SelectSingleNode( "href", string.Empty) Where(node => node.GetAttributeValue( "class", "").Contains( "athing")).Take( 10).ToList() HtmlDocument htmlDoc = new HtmlDocument() If you do not see the reference in your using statements, you must add the following line to every code file where you use the Agility Pack: After you install it, you’ll notice the dependency in your solution, and you will find it referenced in your using statements. In this Window, perform a search for HTML Agility Pack, and install it into your solution dependencies. NuGet is available in the Visual Studio interface by going to Tools -> NuGet Package Manager -> Manage NuGet Packages for Solution. To install the Agility Pack, you need to use NuGet. The first step is to install the HTML Agility Pack after you create your C#. Instead of writing your own parsing engine, the HTML Agility Pack has everything you need to find specific DOM elements, traverse through child and parent nodes, and retrieve text and properties (e.g., HREF links) within specified elements. ![]() The Agility Pack is standard for parsing HTML content in C#, because it has several methods and properties that conveniently work with the DOM. For any project that pulls content from the web in C# and parses it to a usable format, you will most likely find the HTML Agility Pack. ![]()
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