I've been trying to find a way to programmatically add a link to an external CSS file to the <head> tag from markup within the <body> tag in Castle MonoRails and NVelocity view engine. Anyone know how this can be done?
I need to resolve this problem as the page I work on can consist of many "widgets", and each widget would optimally acquire additional assets such as JS and CSS, rather than putting the <link ..> within the body tag and risk rendering problems.
The solutions posted here are not properly working. A better approach is to add your scripts to httpContext.Current.Items
Using same structure as @jishi:
in your view or your viewcomponent, you would be able to invoke something like this:
$Style.Add("/static/style1.css")
and in your layout (head-section):
$Style.Render()
Your helper consists of 2 simple methods using httpcontext to store and retreive the list of files.
public class StyleHelper
{
public static void Add(string file) {
if (string.IsNullOrWhiteSpace(file))
return;
var obj = HttpContext.Current.Items["AssetFiles"] as List<string>; // get the collection which might be empty
if (obj == null || obj.Count == 0) {
IList<string> list = new List<string>();
list.Add(file.ToLower());
HttpContext.Current.Items.Add("AssetFiles", list); // adds your first asset to your collection and returns
return;
}
if (obj.Contains(file.ToLower()))
return; // asset is already added
// new asset ready to be added to your collection
obj.Add(file.ToLower());
HttpContext.Current.Items.Add("AssetFiles", obj);
}
public string Render() {
var obj = HttpContext.Current.Items["AssetFiles"] as List<string>;
if (obj == null || obj.Count == 0)
return ""; // you never added anything to the collection. Nothing more to do.
// not using linq here for the sake of readability:
string res = string.Empty;
foreach (var item in obj) {
res = res + string.Format("<link rel=\"stylesheet\" {0} />", item);
}
return res;
}
}
In your controller (preferably base controller) add this:
[Helper( typeof( StyleHelper ), "Style" )] public class YourController