mca blog

i do a lot of XSLT work in my code. it's my favorite 'big stick.' i'm ready to hit anything with XSLT [grin]. since i also do lots of HTTP/Web work, the current XslCompiledTransform can be a bit sluggish. on top of that, i use the MvpXslTransform *excellent* Mvp.Xml Library. a bit more added weight with it's cool EXSLT features, etc.

so i needed a way to optimize the compiled transforms without interfering with my general code pattern. i decided to use the ASP.NET Cache object to hold the compiled transform for later re-use. now, even though i'm coding a state-less web-app, i can still reuse the compiled transform when i want to - sweet!

here's the method i use:

// get the requested xsl file, instance as xsldoc and store in memory for later
private MvpXslTransform GetXsl(HttpContext ctx, string xslfile)
{
    return GetXsl(ctx, xslfile, new XmlUrlResolver());
}
private MvpXslTransform GetXsl(HttpContext ctx, string xslfile, XmlResolver xmlres)
{
    MvpXslTransform xsldoc = new MvpXslTransform();
    xsldoc = (MvpXslTransform)ctx.Cache.Get(xslfile);

    if (xsldoc == null)
    {
        xsldoc = new MvpXslTransform();
        xsldoc.Load(xslfile, new XsltSettings(true, false), xmlres);

        ctx.Cache.Add(
            xslfile,
            xsldoc,
            new System.Web.Caching.CacheDependency(xslfile),
            System.Web.Caching.Cache.NoAbsoluteExpiration,
            System.Web.Caching.Cache.NoSlidingExpiration,
            System.Web.Caching.CacheItemPriority.Normal,
            null);
    }

    return xsldoc;
}