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I wrote code for my needs (i.e. collecting YouTube links from a page) and it is simple, but now I just want to know what can I do just to make it a better and properly written one. For example, I think I should have try/catch blocks/exceptions in my methods, or get/set properties. What tests can I write to test the code? I don't know to be honest, but how would the code look if you had written it?

public class Parser
{
    public static void Main()
    {
        Console.WriteLine("Enter the url of the page:");
        var url = Console.ReadLine();

        var numOfPages = GetNumberOfPages(url);
        var numOfLinks = 1;

        for (int page = 0; page <= numOfPages; page++)
        {
            if (page != 1)
            {
                if (page == 0)
                {
                    GetYouTubeLink(url).ForEach(x => Console.WriteLine($"{numOfLinks++}." +
                        $"{x.Replace("embed/", "watch?v=").Replace("?feature=oembed", "")}"));
                }
                else
                {
                    var newUrl = url + string.Format($"{page}/");
                    GetYouTubeLink(newUrl).ForEach(x => Console.WriteLine($"{numOfLinks++}." +
                        $"{x.Replace("embed/", "watch?v=").Replace("?feature=oembed", "")}"));
                    newUrl = string.Empty;
                }
            }
        }
    }

    private static HtmlDocument GetWebPageHtmlFromUrl(string url)
    {
        var webGet = new HtmlWeb();

        return webGet.Load(url);
    }

    private static int GetNumberOfPages(string url)
    {
        var pages = GetWebPageHtmlFromUrl(url)
            .DocumentNode.SelectNodes("//div[@class='page-link']")
            .Descendants("a")
            .Last().InnerText;

        return int.Parse(pages);
    }

    private static List<string> GetYouTubeLink(string url)
    {
        var links = new List<string>();
        var iframeLinks = GetWebPageHtmlFromUrl(url).DocumentNode.SelectNodes("//iframe");

        if (iframeLinks != null)
        {
            foreach (var link in iframeLinks)
            {
                links.Add(link.Attributes["src"].Value);
            }
        }

        return links;
    }
}
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  • \$\begingroup\$ CRs are so much easier when I can just paste the code in VS. Thank you! \$\endgroup\$ Commented Apr 30, 2018 at 22:14

1 Answer 1

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Comments inline:

public class Parser
{
    public static void Main()
    {
        Console.WriteLine("Enter the url of the page:");
        var url = Console.ReadLine();

        var numOfPages = GetNumberOfPages(url);
        var numOfLinks = 1;

        for (int page = 0; page <= numOfPages; page++)
        {
            // if (page != 1) is redundant in the original code, did you mean numOfPages?
            var newUrl = url + (page > 0 ? string.Format($"{page}/") : "");
            GetYouTubeLinks(newUrl).ForEach(x => Console.WriteLine($"{numOfLinks++}." +
                x.Replace("embed/", "watch?v=").Replace("?feature=oembed", "")));   // remove string interpolation since it's just one value
            // newUrl = string.Empty;       // Not needed
        }
    }

    private static HtmlDocument GetWebPageHtmlFromUrl(string url)
    {
        var webGet = new HtmlWeb();

        return webGet.Load(url);
    }

    private static int GetNumberOfPages(string url)
    {
        var pages = GetWebPageHtmlFromUrl(url)
            .DocumentNode.SelectNodes("//div[@class='page-link']")  // This parsing may work on specific pages, but it won't work on all pages. This is concerning since the user is prompted to enter any URL?
            .Descendants("a")
            .Last().InnerText;

        return int.Parse(pages);
    }

    private static List<string> GetYouTubeLinks(string url)     // Made plural
    {
        var iframeLinks = GetWebPageHtmlFromUrl(url).DocumentNode.SelectNodes("//iframe");

        if (iframeLinks == null)    // reduce nesting
        {
            return new List<string>(0);
        }

        return iframeLinks.Select(link => link.Attributes["src"].Value).ToList();   // simplify allocation
    }
}
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  • \$\begingroup\$ Actually I am checking if the page is not 1, because the first page actually is 0 and the second is 2. And the other thing is that I am getting the number of pages only from the first one, so I don't need to call this method on every page. \$\endgroup\$
    – beBoss
    Commented May 1, 2018 at 23:12
  • \$\begingroup\$ Why not just make the first page 1? I.e. for (int page = 1; page <= numOfPages; page++) I'm confused by your "getting the number of pages" once comment. I'm only calling GetNumberOfPages once, same as you. My comment about numOfPages wouldn't have required any recalculation, I was just trying to figure out what you were trying to accomplish. \$\endgroup\$ Commented May 2, 2018 at 15:17
  • \$\begingroup\$ Well, will try to explain it. So when I call GetNumberOfPages(), on every page on the bottom there is pagination and the number of pages, So I just call this method on the first page and I have the number of the pages. First page in the URL is like this: website.com/ , the second is website.com/2/ so I don't have page 1 as you suggested me to use if in the for loop (don't have website.com/1/) that's why I check if the loop isn't 1. \$\endgroup\$
    – beBoss
    Commented May 2, 2018 at 20:39
  • \$\begingroup\$ So you could just start at 1 instead of 0 and do var newUrl = url + (page > 1 ? string.Format($"{page}/") : ""); \$\endgroup\$ Commented May 2, 2018 at 23:29
  • \$\begingroup\$ Yep, it works and looks great to be honest, thank you for the help! Great tips and suggestions :) \$\endgroup\$
    – beBoss
    Commented May 3, 2018 at 1:20

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