CodeProject-Tip

C# truncate DateTime

Sky Sanders — Wed, 21 Apr 2010 09:44:12 GMT

Here is an extension method that will let you truncate a DateTime to any resolution...

Usage:

DateTime myDateSansMilliseconds = myDate.Truncate(TimeSpan.TicksPerSecond);
DateTime myDateSansSeconds = myDate.Truncate(TimeSpan.TicksPerMinute)

Class:

public static class DateTimeUtils
{
    /// <summary>
    /// <para>Truncates a DateTime to a specified resolution.</para>
    /// <para>A convenient source for resolution is TimeSpan.TicksPerXXXX constants.</para>
    /// </summary>
    /// <param name="date">The DateTime object to truncate</param>
    /// <param name="resolution">e.g. to round to nearest second, TimeSpan.TicksPerSecond</param>
    /// <returns>Truncated DateTime</returns>
    public static DateTime Truncate(this DateTime date, long resolution)
    {
        return new DateTime(date.Ticks - (date.Ticks % resolution), date.Kind);
    }
}

Using WMI to fetch the command line that started all instances of a process

Sky Sanders — Mon, 12 Apr 2010 02:12:32 GMT

/// <summary>
/// Using WMI to fetch the command line that started all instances of a process
/// </summary>
/// <param name="processName">Image name, e.g. WebDev.WebServer.exe</param>
/// <returns></returns>
/// adapted from http://stackoverflow.com/questions/504208/how-to-read-command-line-arguments-of-another-process-in-c/504378%23504378
/// original code by http://stackoverflow.com/users/61396/xcud
private static IEnumerable<string> GetCommandLines(string processName)
{
    List<string> results = new List<string>();

    string wmiQuery = string.Format("select CommandLine from Win32_Process where Name='{0}'", processName);

    using (ManagementObjectSearcher searcher = new ManagementObjectSearcher(wmiQuery))
    {
        using (ManagementObjectCollection retObjectCollection = searcher.Get())
        {
            foreach (ManagementObject retObject in retObjectCollection)
            {
                results.Add((string)retObject["CommandLine"]);
            }
        }
    }
    return results;
}

Technorati tags: C-Sharp, WMI, CodeProject-Tip

Preventing caching of content in ASP.Net Pages and other HttpHandlers

Sky Sanders — Tue, 23 Mar 2010 14:59:47 GMT

Sometimes I forget to squash caching on my JSON handlers and end up with odd runtime behavior, especially when using IE.

You can ensure that each request actually pulls data instead of hitting the cache by adding this to the top of a handler (.ashx) or in the page_load of a .aspx. Drop 'context.' for use in page_load.

context.Response.Cache.SetExpires(DateTime.UtcNow.AddMinutes(-1));
context.Response.Cache.SetCacheability(HttpCacheability.NoCache);
context.Response.Cache.SetNoStore();

This is what the head of my JSON handlers typically look like:

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ClearContent();
            context.Response.ClearHeaders();
            context.Response.Cache.SetExpires(DateTime.UtcNow.AddMinutes(-1));
            context.Response.Cache.SetCacheability(HttpCacheability.NoCache);
            context.Response.Cache.SetNoStore();
            context.Response.ContentType = "text/json";

Technorati tags: C-Sharp, ASP.NET, CodeProject-Tip

Coerce Windows and Internet Explorer (IE) to diplay JSON text inline

Sky Sanders — Tue, 23 Mar 2010 14:49:07 GMT

Cheeso posted and eventually answered this question on StackOverflow about how to get IE to stop popping a file download dialog when rendering JSON text.

A few things I noticed about the answer that might help others follow:

You need to add the registry editor version as the first line in the .reg file
You might want to also include 'text/json' content type.

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\MIME\Database\Content Type\application/json]
"CLSID"="{25336920-03F9-11cf-8FD0-00AA00686F13}"
"Encoding"=dword:00080000


[HKEY_CLASSES_ROOT\MIME\Database\Content Type\text/json]
"CLSID"="{25336920-03F9-11cf-8FD0-00AA00686F13}"
"encoding"=dword:00080000

Technorati tags: CodeProject-Tip

Building Mono C# compiler (MCS) in Visual Studio 2008

Sky Sanders — Tue, 09 Mar 2010 13:09:59 GMT

If you are an old hand at building Mono on Windows using cygwin, then this post will not be of interest.

The target audience for this post are those who just wish to build MCS, GMCS etc in Visual Studio 2008 without the need for MCS.

Building the Mono C# compiler in Visual Studio 2008 would be as simple as opening gmcs.sln in VS and building if not for the need to generate the cs-parser.cs file.

Supplied in the MCS package in the latest stable, 2.6.1, is cs-parser.jay, which is an input file for the Jay Parser Generator for C#. The C++ source and gnu makefile for Jay are included but the point of this post is to obviate the need to use cygwin, so you can download a precompiled exe from the previous link.

The simplest way to generate your cs-parser.cs file is to copy cs-parser.jay to the Jay directory (to make use of the skeleton file) and run the following command line in the Jay directory:

jay.exe -ctv cs-parser.jay <skeleton.cs >cs-parser.cs

Now, in the compiler solution, delete the missing cs-parser.cs file and paste the freshly generate cs-parser.cs into the solution.

Or just download cs-parser.cs (2.6.1) here.

Now clean and rebuild.

Fini.

Technorati tags: Mono, CodeProject-Tip

Generic NullSafe IDataRecord Field Getter

Sky Sanders — Wed, 03 Mar 2010 00:15:55 GMT

// usage
var name = GetValueOrDefault<string>(reader, "Name");
var name = reader.GetValueOrDefault<string>("Name");
var name = reader.GetValueOrDefault<string>(0);


// extension
public static T GetValueOrDefault<T>(this IDataRecord row, string fieldName)
{
    int ordinal = row.GetOrdinal(fieldName);
    return row.GetValueOrDefault<T>(ordinal);
}

public static T GetValueOrDefault<T>(this IDataRecord row, int ordinal)
{
    return (T)(row.IsDBNull(ordinal) ? default(T) : row.GetValue(ordinal));
}

Technorati tags: C-Sharp, ADO.Net, CodeProject-Tip

Testing and Parsing an ASP.NET YSOD (Yellow Screen Of Death) from an XMLHttpRequest.responseText

Sky Sanders — Sun, 28 Feb 2010 11:46:56 GMT

After a minor bout of forgetfulness regarding legal regexp flags in Javascript, I knocked this one out that parses the comment block at the end of an YSOD.

var rxYSOD = /<!--\s*\[(.*?)]:(\s*.*\s(.*[\n\r]*)*?)\s*(at(.*[\n\r]*)*)-->/;
if (rxYSOD.test(text)) {
    // looks like one..
    var ysod = rxYSOD.exec(text);
    errObj = { Message: ysod[2], StackTrace: ysod[4], ExceptionType: ysod[1] };
}

will find and parse the comment block shown. I am guessing that is why they put it there....

<html>
<!-- omitted -->
    <body bgcolor="white">
		<!-- omitted -->
    </body>
</html>
<!-- 
[ArgumentException]: Unknown web method ValidateUser.
Parameter name: methodName
   at System.Web.Script.Services.WebServiceData.GetMethodData(String methodName)
   at System.Web.Script.Services.RestHandler.CreateHandler(WebServiceData webServiceData, String methodName)
   at System.Web.Script.Services.RestHandler.CreateHandler(HttpContext context)
   at System.Web.Script.Services.RestHandlerFactory.GetHandler(HttpContext context, String requestType, String url, String pathTranslated)
   at System.Web.Script.Services.ScriptHandlerFactory.GetHandler(HttpContext context, String requestType, String url, String pathTranslated)
   at System.Web.HttpApplication.MapHttpHandler(HttpContext context, String requestType, VirtualPath path, String pathTranslated, Boolean useAppConfig)
   at System.Web.HttpApplication.MapHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
-->

Technorati tags: ASP.NET, JavaScript, CodeProject-Tip

Adding a ajax/json endpoint to an existing WCF service

Sky Sanders — Sat, 27 Feb 2010 07:04:17 GMT

Mixing and matching security to get something like this locked down and providing the desired exposure might be challenging but I didn't offer to solve that in the title, did I?

 <system.serviceModel>
    <behaviors>
      <endpointBehaviors>
        <behavior name="webScriptBehavior">
          <enableWebScript />
        </behavior>
      </endpointBehaviors>
      <serviceBehaviors>
        <behavior name="Salient.ScriptModel.Services.DualServiceBehavior">
          <serviceMetadata httpGetEnabled="true" />
          <serviceDebug includeExceptionDetailInFaults="false" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
 
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" />
    <services>
      <service behaviorConfiguration="Salient.ScriptModel.Services.DualServiceBehavior" name="Salient.ScriptModel.Services.DualService">
        <endpoint address="" binding="wsHttpBinding" contract="Salient.ScriptModel.Services.IDualService"/>
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
        <endpoint address="json" behaviorConfiguration="webScriptBehavior" binding="webHttpBinding" contract="Salient.ScriptModel.Services.IDualService"/>
      </service>
    </services>
  </system.serviceModel>

Technorati tags: WCF, Ajax, CodeProject-Tip

WCF to JSON Dates and back again

Sky Sanders — Fri, 19 Feb 2010 05:33:16 GMT

I have been struggling with the seemingly unbeatable UTCness of js Date.getTime in respect to dealing with dates going between javascript and wcf. I tried adding the offset/60/1000, munging local times, closing one eye and sticking out my tongue and nothing. nothing. The server was always getting a utc long and treating it as a local.

I have been following Rick's saga with wcf dates r.e. ajax and gave his solutions a go and got pleasant results with the .parseWithDate() tweak to json2.js but could not get results with the .stringifyWcf(). Got UTC with no offset no matter how much attention I gave it. Maybe I was just not getting something....

In any case...

It turns out that, after reading the source for the server side parser that simply appending '-0000' will force the parser to consider the value as UTC and parse accordingly thus giving the correct local time at the endpoint.

js dates to/from wcf

var tmp = {
    dateFromWcf: function (input, throwOnInvalidInput) {
        var pattern = /Date\(([^)]+)\)/;
        var results = pattern.exec(input);
        if (results.length != 2) {
            if (!throwOnInvalidInput) {
                return s;
            }
            throw new Error(s + " is not .net json date.");
        }
        return new Date(parseFloat(results[1]));
    },
    dateToWcf: function (input) {
        var d = new Date(input);
        if (isNaN(d)) {
            throw new Error("input not date");
        }
        // here is how we force wcf to parse as UTC and give correct local time serverside        
        var date = '\/Date(' + d.getTime() + '-0000)\/';
        return date;
    }
};

Update:

Well, having to munge dates is just dirty and smelly so I went into Rick's json2.js mod and simply added the '-0000' to the replacer and bingo. It works great.

Update: In some roundtripping tests I noticed that stringifyWcf is setting the date field of the object being stringified to the wcf date string. PU! Now that's what I call an undocumented and unexpected side effect. That has been fixed so now you get your object back in the same shape you sent it. ;-)

Update 2:

Now I understand why Rick was modifying the input value, I am not sure he does though, can get no response from several comments left on his blog. In any case, Firefox 3.6 has a bug in the JSON replacer.

So, for FF you need to force json2.js as shown in the post linked above and use this addon:

(function jsonWcfAddons() { // from https://west-wind.com/Weblog/posts/729630.aspx#262650 // with some fairly significant fixes by sky sanders // http://skysanders.net/subtext/archive/2010/02/18/wcf-to-json-dates-and-back-again.aspx if (this.JSON && !this.JSON.parseWithDate) { var reISO = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)Z$/; var reMsAjax = /^\/Date$(d|-|.*)$[\/|\\]$/; JSON.parseWithDate = function(json) { /// <summary> /// parses a JSON string and turns ISO or MSAJAX date strings /// into native JS date objects /// </summary> /// <param name="json" type="var">json with dates to parse</param> /// </param> /// <returns type="value, array or object" /> try { var res = JSON.parse(json, function(key, value) { if (typeof value === 'string') { var a = reISO.exec(value); if (a) return new Date(Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4], +a[5], +a[6])); a = reMsAjax.exec(value); if (a) { var b = a[1].split(/[-+,.]/); return new Date(b[0] ? +b[0] : 0 - +b[1]); } } return value; }); return res; } catch (e) { // orignal error thrown has no error message so rethrow with message throw new Error("JSON content could not be parsed"); return null; } }; JSON.stringifyWcf = function(json) { /// <summary> /// Wcf specific stringify that encodes dates in the /// a WCF compatible format ("/Date(9991231231)/") /// Note: this format works ONLY with WCF. /// ASMX can use ISO dates as of .NET 3.5 SP1 /// </summary> /// <param name="key" type="var">property name</param> /// <param name="value" type="var">value of the property</param> // choking on FF 3.6 date Wed Feb 24 2010 14:02:17 GMT-0700 (US Mountain Standard Time) return JSON.stringify(json, function(key, value) { if (typeof value == "string") { var a = reISO.exec(value); if (a) { // SKY: the '-0000' forces the serverside serializer into utc mode resulting in accurate dates. var val = '/Date(' + new Date(Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4], +a[5], +a[6])).getTime() + '-0000)/'; //SKY: rick, I don't think that asking for a JSON representation // of an object should modify the state of the object. my 2 pesos. //this[key] = val; // this is the value that SHOULD be getting serialized but in the // FF native JSON is ignoring this and serializing the member so I am guessing // that is why rick is modifying the input object. gets the serialization job // done properly but is a rather nasty undocumented side effect, in my opinion. // I think it is probably better to overwrite native JSON with json2.js and // get consistant results across platforms with out the need to modify the input // UNLESS of course you are never going to need to use any of the objects that you // serialize... return val; } } return value; }) }; JSON.dateStringToDate = function(dtString) { /// <summary> /// Converts a JSON ISO or MSAJAX string into a date object /// </summary> /// <param name="" type="var">Date String</param> /// <returns type="date or null if invalid" /> var a = reISO.exec(dtString); if (a) return new Date(Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4], +a[5], +a[6])); a = reMsAjax.exec(dtString); if (a) { var b = a[1].split(/[-,.]/); return new Date(+b[0]); } return null; }; } })();

Technorati tags: WCF, Ajax, Javascript , CodeProject-Tip

Get CustomAttributes the easy way....

Sky Sanders — Thu, 21 Jan 2010 01:50:48 GMT
A few extension methods to help out.....
// Project: Salient.Reflection // http://salient.codeplex.com using System; using System.Collections.Generic; using System.Linq; using System.Reflection; public static class AttributeHelpers { /// <summary> /// Returns first non-inherited custom attribute of type T /// </summary> public static T GetCustomAttribute<T>(this ICustomAttributeProvider provider) where T : Attribute { return GetCustomAttribute<T>(provider, false); } /// <summary> /// Returns first custom attribute of type T in the inheritance chain /// </summary> public static T GetCustomAttribute<T>(this ICustomAttributeProvider provider, bool inherited) where T : Attribute { return provider.GetCustomAttributes<T>(inherited).FirstOrDefault(); } /// <summary> /// Returns all non-inherited custom attributes of type T /// </summary> public static List<T> GetCustomAttributes<T>(this ICustomAttributeProvider provider) where T : Attribute { return GetCustomAttributes<T>(provider, false); } /// <summary> /// Returns all custom attributes of type T in the inheritance chain /// </summary> public static List<T> GetCustomAttributes<T>(this ICustomAttributeProvider provider, bool inherited) where T : Attribute { return provider.GetCustomAttributes(typeof (T), inherited).Cast<T>().ToList(); } }

Technorati tags: C#, Reflection , CodeProject-Tip