Final application available at http://winphp.juokaz.com:82/.

Goal was:

My project will allow people to upload huge collections of photos (probably archived in one zip file) and get nice online gallery.

I decided not to use archived files and simply allowed to upload multiple files using Silverlight control, but pretty much everything left the same. My approach to this competition was to focus on technologies and not on functionality. That’s why I spent huge amount of time creating abstractions and making parts of application to be very customizable and not adding a lot of functions.

Functions in my app are really easy to add and in a matter of some lines one can add various parameters to images (tags, name etc.) and then sort/filter them – a lot of hard work is done under the hood. Silverlight based gallery is also absolutely independent from whole application and will work as long as front-end supplies correct gallery xml file, hence it can be easily customized.

Rules had 4 criterias:

1. Application originality – I think I passed this one
2. Completeness – I have done everything what I’ve wanted
3. Use of Windows specific features/services – uses COM objects, Silverlight
4. Documentation of the process – articles in this blog and a lot of tweets

I think I have done everything that was required and now will try to push this application even further. Maybe Microsoft itself will show interest in it, because what I’ve done and used has been key topics in MIX 09.

Silverlight part and images processing is based on Jellyfish library. At first I used Microsoft libraries, but soon I got stuck because of lack of documentation and functionality. However Jellyfish is far from perfect – a lot of things are hardcoded, made private and hard to change. Also, it has some functions which are useful only in rare cases and need to be removed. For example, each mouse move, click and scroll used to look through all images in scene (using loop) and detect which one is under the mouse cursor. Very inefficient (especially if you don’t need it).

Zend Framework was used to power whole website. I didn’t find any difference running it on Windows from running on Linux, so I can’t say much about anything specific. However, I decided to use the new Sql driver implementation for PHP, but it wasn’t included in Zend Framework supported adapters list. That’s why me and Rob Allen started a project at codeplex to create an adapter for sql driver. It’s almost complete and at least both of us use it for our projects – everyone is free to test it and suggest changes though.

Windows was good enough. I haven’t used Windows for any development for more than two years, but it worked surprisingly good. NetBeans works the same in all platforms, but Visual Studio was almost a new thing. Nevertheless, both have done their job. IIS was a new thing too, but I didn’t find a big difference for a developer, only that it allows to change everything without touching config files – I found it faster when settings are in multiple places.

Community is outstanding. Stuart Herbert,  Rob Allen, Alton Crosslen and organizer Bram Veenhof were all chatting on Twitter and it felt more like a community project and not a competition. Also the level of entries, from my point of view, is really high – this competition doesn’t had a lot of entrants (only slightly more than 10), but all of them are really competitive.

It was really a great time.

1. PHP extensions
2. COM objects, programs executed with exec()

Today I’m going to look at all of them and explain my choice to use COM objects and not others from above.

Three choices

PHP extensions (how to create them read here) are fast and (at least should be) stable. However they are quite hard to create at start and uses C. For example, I’m now using library written in C# and rewriting it in C just to use it as extension is way to complicated and time consuming (and probably not worth it). I can only image PHP extensions as libraries to optimize some parts of code or to be used in multiple projects. In my case, I only need to some limited tasks.

Next logical choice would be executing programs with exec(). In my opinion it’s the easiest way because programs can be created with any language you like, can be supplied with source code and none of system settings need be changed. If exec() is not blocked in php.ini it’s very practical solution.

Windows users has an option to use COM objects. COM objects stand somewhere between PHP extensions and exec(). They can be created in many languages, but libraries are not executed outside PHP script – they behave as normal PHP objects (almost). They are more convenient to work with than compiled programs, but need to registered with Windows.

The best

I was testing last two solutions for more than two weeks and my final choice is… COM objects.  To explain this choice here is a short story:

I have a webpage which allows uploading multiple pictures. Two files are uploaded in parallel and once uploaded they are processed (resized, thumbnail and special structure for DeepZoom is created). All this processing is written in C# and uses various windows and 3rd-party libraries.

At first I tried compiling a program as “console application” (in VisualStudio) and then run it with exec(). It worked as expected, but was a little bit too slow. Script was taking around 3 s. to execute, even though actual program ran in 1 s. I didn’t spent much time analyzing where overhead was coming from but it was clear that it can be optimized.

So I compiled program as “class library”, registered it with the Windows assembly cache and then used with a DOTNET class. First problem was IIS server – it kept throwing 500 errors no matter what I did. I didn’t wanted to waste my time trying to find where was a problem – after changing to COM class it magically started to work (even though it uses the same library). Using my library inside PHP was much more faster and execution time reduced to less than a second (depends on a size of image).

Conclusion

I have tested most of possible ways to execute external code. Even though COM objects perform better they can’t be suggested as default choice, because libraries need to registered with a system what can be problematic and maybe not even possible. So if you have limited permissions to server – use exec(), but in all other cases – I definitely recommend using COM. PHP extensions are even better, but harder to code and limited to C.

Configuration syntax

Flash uses flashvars object parameter which is easy to use and passed variables automatically become available within actionscript variables scope. Luckily, Silverlight has almost the same thing.

Flash: name1=value1&name2=value2&name3=value3
Silverlight: name1=value1,name2=value2,name3=value3

To start with, lets create a simple script which will form an arguments string (you can use array of params and then implode with ‘,’, but for the sake of simplicity I just use static string):

$connect = '/users/juozas';
$args = "Connect=" . urlencode($connect) . ",id=1,somethingElse=true";

Inside an object element in HTML add this code (depending on framework you (not)use you may need to change it to work as a template or a view script):

<param name="initParams" value="<?php echo $args; ?>" />

Reading configuration in Silverlight

If you start with a default Silverlight project in Visual Studio, you initially have two classes: App and Page. App is a main class, which (by default) on start up creates a new Page instance and assigns it to a root visual element of itself (App), where Page is your actual Silverlight application (visual part, controls, etc.). Standard start up event in App looks like this:

private void Application_Startup(object sender, StartupEventArgs e)
{
    this.RootVisual = new Page();
}

To use parameters from HTML tag, we need to get initParams from the passed e argument (which has type of StartupEventArgs) and set corresponding properties of some object to their values. You can have global static configuration class, but (also for simplicity) I just pass them to the Page instance:

private void Application_Startup(object sender, StartupEventArgs e)
{
    Page page = new Page();
 
    if (e.InitParams.Keys.Contains("Connect") && 
        !string.IsNullOrEmpty(e.InitParams["Connect"]))
    {
     page.connectPath = HttpUtility.UrlDecode(e.InitParams["Connect"]);
    }
 
    this.RootVisual = page;
}

Here I’m setting connectPath using Connect from initParams. One last thing – don’t trust user input, if you have integers, use Int32.Parse() and always check if passed values are in range of expected values. It’s really important to remember that SQL injections and other similar attacks are also threat in Silverlight (as Flash also).

Outside information sources

However, not all properties can be passed initially – some times it’s required to refresh information from server during actual runtime (think AJAX). You can easily create asynchronous calls to server from Silverlight too (works almost exactly the same as normal JavaScript AJAX script):

public Page()
{
    InitializeComponent();
 
    LoadButton.Click += new RoutedEventHandler(LoadButton_Click);
}
 
void LoadButton_Click(object sender, RoutedEventArgs e)
{
    var wc = new WebClient();
    wc.OpenReadCompleted
            +=new OpenReadCompletedEventHandler(wc_OpenReadCompleted);
    wc.OpenReadAsync( new Uri( "/script.php?id=1", UriKind.Relative ) );
 
    Text.Text = "Loading...";
}
 
void wc_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
    if ( e.Error != null )
    {
        // Do something with an error
        Text.Text = e.Error.ToString();
    }
    else
    {
        try
        {
            // e.Result has a type of Stream, so we need to read it first
            // (not just cast to string)
            StreamReader rdr = new StreamReader(e.Result);
            Text.Text = rdr.ReadToEnd();
        }
        finally
        {
            if ( e.Result != null ) e.Result.Close();
        }
    }
}

This code creates onClick event which asynchronously downloads “/script.php?id=1″ and sets results to TextBlock element named “Text”. You can use absolute URLs too, but don’t forget that cross-domain requests protection will try to block it. Look here to read more about how to avoid it. Not even localhost will work if you are testing with VisualStudio (witch creates temporary “ASP.NET development server” with random port (not 80)), so make sure to check it first.

As you can see it’s very easy and simple to create dynamical Silverlight applications. I have done some work with Flash too (probably more than with Silverlight, especially with ActionScript language) and I can confirm that there isn’t much difference. Silverlight is more like Flex though.

Making your library COM visible requires that you register the DLL in the GAC and registering something in the GAC should only be done when multiple applications need to access the same version of the same library. Even then, most software houses will deploy each app with it’s own copy of the DLL instead of using the GAC.

Nevertheless, C# (and most of other languages) support Reflection. Basically using reflection, programs can “observe and modify its own structure and behavior” (wiki). .NET has System.Reflection namespace with all needed methods. Purpose of this post is to find a way how to load DLL’s dynamically – without worrying about registering, re-registering, unregistering them in running system/production servers.

DLL’s are library assemblies, which “contain code in CIL, which is usually generated from .NET languages, and then compiled into machine language at runtime by the CLR just-in-time compiler.” (from). For all not familiar with assemblies, assembly “is a reusable, versionable, and self-describing building block of a common language runtime application.” (from). Consider this code:

using System;
using System.Reflection;
 
namespace Php
{
    public class Reflection
    {
        public Object get(string assembly, string className)
        {
            Assembly asm = Assembly.LoadFrom(assembly);
 
            return asm.CreateInstance(className, true);
        }
    }
}

This is very basic class, which can be used to do such things as:

Php.Reflection obj = new Php.Reflection ();
Object my = obj.get("my.dll", "namespace.class");

You may have thought that this class is absolutely useless, because you can simply use System.Reflection.Assembly without wrapping it into separate class. However, I was writing this code with an intention to use it as COM object in PHP and because PHP can’t access static COM class methods (which I find very disappointing) I needed to create this class. Now in PHP you can write:

$obj = new Com ("Php.Reflection");
$math = $obj->get("math_class.dll", "phpclass3.first");

This method, in my opinion, is much much more better than registering every single class with global assembly cache. It’s more practical and maintainable to have all required libraries in the same project directory, and not somewhere in Windows core. However, benchmarks are still coming so stay tuned.

* For everyone interested in Winphp contest, and people building PHP apps in Windows, I recommend reading www.eurowinphp.com blog, which aggregates all participants blogs. For example, Timmy Kokke, another WinPHP participant, recently wrote another great tutorial how to make your .NET classes accessible in PHP. Also, you can follow my on Twitter at twitter.com/juokaz.

I followed this tutorial, which has most of required information. Firstly, you create your “Class library”, then create assembly key file and assign it to project assembly. After project is built, you register and add to global assembly cache your library. Probably it’s quite natural process for all .NET developers, but for PHP developer like me, registering something with whole system seemed quite odd (dll hell?).

First problem was ComVisible. ComVisible is a keyword in assembly which is used to control types visibility: “If you need to access a type in this assembly from COM, set the ComVisible attribute to true on that type”. VisualStudio by default sets it to false, so all types are hidden and trying to register dll will result in this warning:

RegAsm : warning RA0000 : No types were registered

Luckily, I find out about ComVisible property quite soon – it’s quite hard to know about it if you haven’t done anything serious with .NET. Nevertheless, after setting it to true, everything should work fine. Sometimes VisualStudio (2008 Professional Edition) refused to build project because of locked dll, so don’t forget to try to kill PHP-CGI process first (Ctrl+Alt+Del). I didn’t had any other problems.

After some tests and failures I ended up with two simple C# classes and PHP caller. Class1 has two public variables (x, y) which are set by PHP in $math object. Method Class1.sum() creates new Math object with constructor parameters x and y, and calls getSum() which returns sum of x and y. Useless stuff, but it worked great to test if:

• COM objects works
• One class can call another (Class1 -> Math)
• Types are correctly understood/converted

Working PHP code (phpclass2 is C# library namespace):

$math = new COM ("phpclass2.Class1");
$math->x = 100;
$math->y = 100;
 
echo "sum = " . $math->sum();
 
unset($math);

Which successfully outputted:

sum = 200

I tried this code with the same Web Platform I used in Windows Server 2008, but now with older IIS (v5, Windows XP) and it worked perfectly with all default settings. Also, IIS control panel in Server 2008 is 10 times better than in Windws Xp – in Xp-one I couldn’t even find how to add new virtual host (my bad, but in IIS 7 it’s way easier to do). And because I was installing it second time, it took me only few minutes.

Getting this to work was probably one of the biggest milestones – actual frontend code and Deepzoom C# library is not that tricky. After some days of working with PHP+Windows things are starting to get a shape – except of different OS GUI, web server works good in both Linux and Windows – clearly Microsoft is holding this competition to show it. And they are in the right way.

Luckily, I had Windows XP in VirtualBox so I tried it. And it worked really well. I’m using university internet network so connections speeds are very fast and Ubuntu -> Windows Xp -> Windows Server 2008 worked just fine. Later I will probably use real Windows system, but for first steps virtual machine worked much more faster than I expected.

Almost 4 years ago I had experience installing IIS server, but I haven’t done much since then. Nevertheless, installing IIS+PHP was really easy – I followed this tutorial, which shows you how to install Microsoft Web Platform, and IIS was ready. Platform installer allows you to install not only SQL, PHP, ASP.NET, etc. but also various web applications – Wordpress, Drupal and many more. Experience with IIS was very similar to Zend Server, but IIS control panel is way better.

I chose to install Wordpress, just to test if IIS is working properly, but Platform installer doesn’t install MySQL. PHP is installed with MySQL extension, but no server is being installed – quite illogical. However, installing MySQL server is as easy as installing any other windows application (subjective) – download installer, Next, Next, Next and server is running. Also, mysql tool works the same in Windows cmd and Linux console.

Tutorials and other information:

• Creating your PHP dev environment for the WinPHP Challenge
• Microsoft Web Platform
• Setting up MySQL for PHP applications
• PHP on IIS7

What I liked very much is GUI for web server control. Currently I have 13 web apps running in my laptop and every app has different port (localhost:80, localhost:81, localhost:82, etc.), but I haven’t found any good tool for adding more sites. I would like to have simple tool, which would accept port number and directory, and create virtual host. IIS control application allows it very easily.

In conclusion, working with PHP in Windows server seems to be pretty acceptable. I haven’t tested setting up anything except Wordpress, but Wordpress seems to work just fine. Especially I liked using GUI, because most of tasks for development machine can be done much more easier and faster, still I’m not going to switch from Linux yet.

Advantages:

• GUI
• Easy to setup
• PHP works

Disadvantages:

• Some functionality is hard to find
• Differences from Apache (mod_rewrite, etc.)

My project will allow people to upload huge collections of photos (probably archived in one zip file) and get nice online gallery. Users will have selection of Ajax or Silverlight version and password protection for galleries. If I have time, I will also add ability to select different photos shuffle style, background theme and/or music, and maybe even automatic tour with captions.

PHP will work as front-end language (with Zend Framework), and C# will be responsible for all Deep Zoom work (which I haven’t tried/tested yet, but I believe it will work). Not only it’s quite useful app, but also showcases a lot of cool technologies. Leaseweb, sponsor of this competition, provided us with dedicated servers so I will hopefully publish alpha version in some weeks.

Why I chose to participate? Firstly, it’s good experience, because I do a lot of PHP, but also more and more C#, so it’s great opportunity to learn more. Secondly, in my belief, such competitions are really useful for portfolios and CV’s – I’m currently looking for a job, so it can help. Lastly, competitions are fun, so, I’m in.

Part of competition requirements is “blog about your experiences with Windows Server 2008 during the contest” so I’ll write around 2-3 posts every week about project status, problems with switching from Linux back to Windows and more. Also, I’m really bad in designing websites, so if anyone would like to help me – please feel free to contact.