Question

I used to embed YouTube video’s via a link I have in a database.

YouTube no longer allows me to embed in this fashion. Instead, I need to extract the video ID from the URL I have stored.

Here is an example of the link:

http://www.youtube.com/watch?v=72xSxQIRelc&feature=youtube_gdata

The ID I need to extract is 72xSxQIRelc. I know I could do something like:

string vidID = 
    preURL.Substring(preURL.LastIndexOf("v=") + 2,
    preURL.Substring(preURL.LastIndexOf("v=") + 2).Length -
    preURL.Substring(preURL.LastIndexOf("&feature")).Length)

I’ve seen some Regex stuff on here that does this. I’m wondering if my way is horribly inefficient, comparatively. I’m also not a regex kung fu wizard, so I’m not sure if the solutions I’m seeing are scalable if YouTube changes the URL structure (in this case, it’s hard coded to require v= as well as &feature).

My solution still seems pretty hackish to me. Is there a more efficient way of doing this?

---

Added

This app is wrapped in a silverlight solution, so I should mention that here.

One posted solution was to use HttpUtility.ParseQueryString. That looked like it was the answer, up until I discovered that Silverlight’s implementation of HttpUtility doesn’t include the ParseQueryString method.

Answer 1

then you should just update your database no?

UPDATE 
    [VideosTable]
SET
    video_url = 
        SUBSTRING(
            video_url, 
            CHARINDEX('v=', video_url) + 2,
            CHARINDEX('&', video_url, CHARINDEX('v=', video_url)) -
            (CHARINDEX('v=', video_url) + 2)
        )
WHERE
    video_url LIKE '%youtube.com%'; 

Then you can simply use the video ID that comes from the Database…

if you are uploading the video ID from the hole link, use the URI object instead

Uri youtube = new Uri("http://www.youtube.com/watch?v=72xSxQIRelc&feature=youtube_gdata");
string videoId = HttpUtility.ParseQueryString(youtube.Query)["v"];

---

Silverlight update

Silveright lack two things, the support for the ParseQueryString part of the System.Web.HttpUtility and the System.Collections.Specialized.NameValueCollection

So, why not just add that functionality yourself?

Because HttpUtility is already a static object you can’t extend this, but you can easily create yourself something new:

public static class MyHttpUtilities
{
    public static System.Collections.Generic.Dictionary<string, string>
        ParseQueryString(this string queryString)
    {
        System.Collections.Generic.Dictionary<string, string> r = 
            new Dictionary<string, string>();
        // remove extra noise
        queryString = queryString.TrimStart('?').Replace("amp;", ""); 
        // split up and fill up Dictionary
        foreach (string s in queryString.Split('&'))
        {
            if (s.Contains('='))
            {
                string[] par = s.Split('=');
                r.Add(par[0], par[1]);
            }
        }
        return r;
    }
}

and then use:

string videoId = MyHttpUtilities.ParseQueryString(youtube.Query)["v"],
       feature = MyHttpUtilities.ParseQueryString(youtube.Query)["feature"];