HOW TO WRITE A AUTOMATION WEBSCRAPER FULL
Those are the full xpaths for each targeted HTML element. Now you might be wondering what those long strings are in the method call. There are several calls to a method that will perform the extraction of the data we are looking for. We then load the HTML that we received back from the network call into our HTML document object. If not, an exception is thrown with a few details of the failing network call. Right after that, we ensure the call out to the website results in a success status code. Then, there is an HTTP call out to the website we want to hit. The first step is setting up an HTML document object that will be used to load HTML and parse the actual HTML document we get back from the site. The method “GetCovidStats” performs a few simple tasks to get our data from the website. The web scraper class has a couple of class-level fields, one public method, and a few private methods. This class will utilize a few components from the HtmlAgilityPack package that was brought into the project earlier.
Now it’s time to start coding the web scraper class. Here is a snapshot of the resource model that will be used for the web scraper. Since the web scraper component will be pulling in multiple sets of data, it is good to capture them inside a custom resource model.
Once that package has been installed into our solution, we can then start coding. The NuGet package is called HtmlAgilityPack. Luckily, there is only one dependency we need to install. Now that we have that out of the way, we need to bring in the dependencies for this solution. I plan to fetch the total number of USA cases, new USA cases, and the date that the data was last updated. Next, we need to pick out what data to fetch from the website. I feel that the CDC’s COVID-19 site is an excellent option for this demo.
Let’s first select a website to scrape data from. Here is a list of Azure resources that were created for this demo:īefore we start writing code, we need to take care of a few more things first.
However, you can have your Azure Function utilize a completely different trigger type, and your web scraper can be written in other languages if preferred. Let’s get started with building a web scraper in an Azure Function! For this example, I am using an HTTP Trigger Azure Function written in C#. It should go without saying, but please be a good Samaritan when web scraping since it can negatively impact site performance. So some automation tasks might need to abide by the use of the site’s cookies/session state. One thing to keep in mind, if you want to web scrape, is that some websites will be using cookies/session state. Some of these abilities will depend if the site allows web scraping or not. Web scraping is a powerful tool for automating certain features such as filling out a form, submitting data, etc. Web scraping is the process of programmatically analyzing a website’s Document Object Model (DOM) to extract specific data of interest. I’ve recently developed a specific interest in a less discussed facet of web development: web scraping.
HOW TO WRITE A AUTOMATION WEBSCRAPER SOFTWARE
Software developers can make snappy, eye-catching websites, and build robust APIs. Web development is arguably the most popular area of software development right now.
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