David,
I use a couple of static htmlhelpers in my code for exactly this scenario. it works on the principle that the context.items collection gets populated per request and therefore if an item exists in the context.items collection then it doesn't get added twice. anyway, enough of the scottish words of wisdOOOm, 'yill jist be waantin the coade'...
for our Scripts:
public static MvcHtmlString Script(this HtmlHelper html, string path)
{
var filePath = VirtualPathUtility.ToAbsolute(path);
HttpContextBase context = html.ViewContext.HttpContext;
// don't add the file if it's already there
if (context.Items.Contains(filePath))
return MvcHtmlString.Create("");
// add the beast...
context.Items.Add(filePath, filePath);
return MvcHtmlString.Create(
string.Format("<script type=\"text/javascript\" src=\"{0}\"></script>", filePath));
}
for our cuddly css:
// standard method - renders as defined in as(cp)x file
public static MvcHtmlString Css(this HtmlHelper html, string path)
{
return html.Css(path, false);
}
// override - to allow javascript to put css in head
public static MvcHtmlString Css(this HtmlHelper html,
string path,
bool renderAsAjax)
{
var filePath = VirtualPathUtility.ToAbsolute(path);
HttpContextBase context = html.ViewContext.HttpContext;
// don't add the file if it's already there
if (context.Items.Contains(filePath))
return null;
// otherwise, add it to the context and put on page
// this of course only works for items going in via the current
// request and by this method
context.Items.Add(filePath, filePath);
// js and css function strings
const string jsHead = "<script type='text/javascript'>";
const string jsFoot = "</script>";
const string jsFunctionStt = "$(function(){";
const string jsFunctionEnd = "});";
string linkText = string.Format("<link rel=\"stylesheet\" type=\"text/css\" href=\"{0}\"></link>", filePath);
string jsBody = string.Format("$('head').prepend('{0}');", linkText);
var sb = new StringBuilder();
if (renderAsAjax)
{
// join it all up now
sb.Append(jsHead);
sb.AppendFormat("\r\n\t");
sb.Append(jsFunctionStt);
sb.AppendFormat("\r\n\t\t");
sb.Append(jsBody);
sb.AppendFormat("\r\n\t");
sb.Append(jsFunctionEnd);
sb.AppendFormat("\r\n");
sb.Append(jsFoot);
}
else
{
sb.Append(linkText);
}
return MvcHtmlString.Create( sb.ToString());
}
usage in both cases:
<%=Html.Css("~/Content/Site.Css")%>
<%=Html.Script("~/Scripts/default.js")%>
have fun...
[edit] - pay particular attn to the comment line:
// this of course only works for items going in via the current
// request and by this method
