I'm looking for a regular expression to isolate the src value of an img. (I know that this is not the best way to do this but this is what I have to do in this case)
I have a string which contains simple html code, some text and an image. I need to get the value of the src attribute from that string. I have managed only to isolate the whole tag till now.
string matchString = Regex.Match(original_text, @"(<img([^>]+)>)").Value;
string matchString = Regex.Match(original_text, "<img.+?src=[\"'](.+?)[\"'].*?>", RegexOptions.IgnoreCase).Groups[1].Value;
.+? between img and src, so there can be all kinds of characters ...Regex.Match(original_text, "<img.*?src=[\"'](.+?)[\"'].*?>", RegexOptions.IgnoreCase).Groups[1].Value;
I know you say you have to use regex, but if possible i would really give this open source project a chance: HtmlAgilityPack
It is really easy to use, I just discovered it and it helped me out a lot, since I was doing some heavier html parsing. It basically lets you use XPATHS to get your elements.
Their example page is a little outdated, but the API is really easy to understand, and if you are a little bit familiar with xpaths you will get head around it in now time
The code for your query would look something like this: (uncompiled code)
List<string> imgScrs = new List<string>();
HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(htmlText);//or doc.Load(htmlFileStream)
var nodes = doc.DocumentNode.SelectNodes(@"//img[@src]"); s
foreach (var img in nodes)
{
HtmlAttribute att = img["src"];
imgScrs.Add(att.Value)
}
I tried what Francisco Noriega suggested, but it looks that the api to the HtmlAgilityPack has been altered. Here is how I solved it:
List<string> images = new List<string>();
WebClient client = new WebClient();
string site = "http://www.mysite.com";
var htmlText = client.DownloadString(site);
var htmlDoc = new HtmlDocument()
{
OptionFixNestedTags = true,
OptionAutoCloseOnEnd = true
};
htmlDoc.LoadHtml(htmlText);
foreach (HtmlNode img in htmlDoc.DocumentNode.SelectNodes("//img"))
{
HtmlAttribute att = img.Attributes["src"];
images.Add(att.Value);
}
SelectNodes call (or check for its existence before getting the att.Value.. And either check the result for null or tack ?? new HtmlNodeCollection(null); to the call of SelctNodes. You'll get NullReferenceException otherwise.This should capture all img tags and just the src part no matter where its located (before or after class etc) and supports html/xhtml :D
<img.+?src="(.+?)".+?/?>
The regex you want should be along the lines of:
(<img.*?src="([^"])".*?>)
Hope this helps.
you can also use a look behind to do it without needing to pull out a group
(?<=<img.*?src=")[^"]*
remember to escape the quotes if needed
This is what I use to get the tags out of strings:
</? *img[^>]*>
Here is the one I use:
<img.*?src\s*?=\s*?(?:(['"])(?<src>(?:(?!\1).)*)\1|(?<src>[^\s>]+))[^>]*?>
The good part is that it matches any of the below:
<img src='test.jpg'>
<img src=test.jpg>
<img src="test.jpg">
And it can also match some unexpected scenarios like extra attributes, e.g:
<img src = "test.jpg" width="300">
