mca blog

the last post was a bit long (and vague), so i figured i'd post a follow up here. with the new CheckPut... utility methods, i can clean up my resource code that handles PUTs. below is an example from my FileHandler class":

Requestor req = new Requestor();
ExyusPrincipal ep = (ExyusPrincipal)this.Context.User;
req.Credentials = new NetworkCredential(((ExyusIdentity)ep.Identity).Name, ((ExyusIdentity)ep.Identity).Password);

// load headers for request
PutHeaders ph = new PutHeaders(this.Context);
if (ph.IfMatch != string.Empty)
    req.RequestHeaders.Add(Constants.hdr_if_none_match, ph.IfMatch);
if (ph.IfUnmodifiedSince != string.Empty)
    req.RequestHeaders.Add(Constants.hdr_if_modified_since, ph.IfUnmodifiedSince);

// make request for existing resource
try
{
    out_text = req.Execute(
        string.Format("{0}://{1}{2}",
            this.Context.Request.Url.Scheme,
            this.Context.Request.Url.DnsSafeHost,
            this.Context.Request.RawUrl),
        "head", "text/xml");

    // record exists, this must be an update
    etag = util.GetHttpHeader(Constants.hdr_etag, (NameValueCollection)req.ResponseHeaders);
    last_mod = util.GetHttpHeader(Constants.hdr_last_modified, (NameValueCollection)req.ResponseHeaders);
    // sort out update conditions
    util.CheckPutUpdateCondition(ph, etag, last_mod, ref put_error, ref save_item);
}
catch (HttpException hex2)
{
    // record not there or some other error
    int code = hex2.GetHttpCode();

    switch (code)
    {
        // record exists w/o changes, we can update!
        case (int)HttpStatusCode.NotModified:
            save_item = true;
            break;
        // see if it's ok to save
        case (int)HttpStatusCode.NotFound:
            // sort out create conditions
            util.CheckPutCreateCondition(ph, this.AllowCreateOnPut, etag, ref put_error, ref save_item);
            break;
        // some other error, omgz!
        default:
            put_error = hex2.Message + " Unable to create.";
            save_item = false;
            break;
    }
}