miércoles, 28 de enero de 2009

Steps to deploy an ASP.NET 2.0 web application in Apache 2 using mod_mono 2.2 (In OpenSuse 11)

this is a quick list of the steps required to deploy .Net applications under Apache 2 and mod_mono in OpenSuse 11

  1. Compile your web application. You can do it on Linux using MonoDevelop or using Visual Studio 2008, we usually compile it on Linux just to be sure the website will no have problems to start.
  2. Create a folder for your application.

    In our case we created a folder named "WebApp " under this directory:


    just because there were other demo applications that come with mono.

    Be sure to give this folder the right permissions. open a Console and log in as the root user (sudo -s) and move to the folder. Use the chmod command to change the permissions if necessary (chmod 777 ./ will enable all the permissions under this folder, you can try adding only the necessary access level, because 777 enable all of them)

  3. copy the contents of the compiled web application to the new folder created.
  4. navigate to the folder "/etc/apache2/conf.d" and create a text file named "WebApp.conf"
  5. copy this code inside the file
        Alias /WebApp /usr/share/mono/asp.net/apps/WebApp
        MonoApplicationsConfigFile WebApp /etc/xsp/2.0/applications-available/WebApp.webapp
        MonoServerPath WebApp "/usr/bin/mod-mono-server2"
        MonoSetEnv WebApp MONO_IOMAP=all
        <Location /WebApp>
         Allow from all
         Order allow,deny
         SetHandler mono
         MonoSetServerAlias WebApp
  6. As you can see in the line 2 we point to a WebApp file that should be located in the /etc/xsp/2.0/applications-available/, so navigate to that folder an create a WebApp.webapp text fileand put this code inside this file:
    <?xml version="1.0" ?>
  7. Now is time to restart apache, so run this command: "apache2ctl restart".
  8. Now open your browser and navigate to http://localhost/WebApp/Default.aspx (if Default.aspx exist or maybe other page that you have in the site)
  9. If all went without errors now you can enjoy your new website running under Apache 2 using mod_mono 2.2

Notes: There a lot of things that could go, wrong, maybe you will need to first Install Apache 2, if you don't already have it in your Linux distro, or maybe the mod_mono 2.2. Those tasks are out of the scope of this post. The present list of steps were written here just to never forget them.if you need help to install apache 2 or mod_mono, or even MONO 2.2, then you will need to do some googling by yourself. sorry :(

martes, 27 de enero de 2009

MONO Formview/ObjectDataSourceView Bug?. Why some of the sections of my website Dissapear?

UPDATE : MONO Has Fixed this Bug in the 2.4 release, at least it seems to be fixed looking at the source code

But it seems to fail when the result is null because it returns a new Object collection with a null element wich seems to be wrong, so this patch could still apply under some circunstances

Well some days ago, while we’re developing our current project release using MONO 1.9.1, MONO 2.0 were released. It was including a lot of bugfixes and new features. So now we were able to compile the application in Linux without make any modification. We were really happy.

But our happiness was futile. Suddenly we realize that some portions of the Website were  not been rendered. We review the rendered code and realized that the formviews were not been rendered properly.

The Gridviews and other ASP.NET controls were rendering good, but, not the formviews. As we had to continue with the project release, we decide to turn back to MONO 1.9.1. At the end of the past Sprint, we decide to rertun and investigate why the the Formviews were not rendering.

First we were suspecting that it could be maybe a Viewstate Issue, (When we turned off the viewstate for the formview controls in MONO 1.9.1 they were not rendered also, turning the viewstate on solved the issue). But turning on or off the viewstate in MONO 2.0.x had no effect. The formview were still not rendered.

So, after some time of digging into the code, creating our custom Formview controls that inherited the ASP.NET Formview, overriding some methods and using the Response as Console for debugging (God! Mono needs a Debugger!) we found the issue.

So, here is:

The problem is located at the ExecuteSelect Method of the ObjectDataSourceView Class that is located in this path inside the MONO Source directory:


(The MONO sources can be obtained from this location)

the method has this lines of code that could be wrong:

if (result is IEnumerable)
return (IEnumerable) result;
return new object[] {};

As you can see when you have methods that return only a single instance of an entity, and those methods are used as the SelectMethods of the ObjectDataSource Controls, the ExecuteSelect will consider they’re not IEnumerable instances so it will return an Empty collection, causing that the Formview Controls render nothing at the Aspx pages.

the correct code should be:

if (result is IEnumerable)
return (IEnumerable) result;
return (result != null)? new object [] { result } : new object[] {};

as you can see, now only if the result is null will be returned an empty collection otherwise a collection with exactly one element is returned.

So doing that modification, and recompiling the MONO Sources you could make your Formview Controls work properly again.

I reported the bug, but I’m not so sure if that is really a bug, (because maybe it is intended to work like that in the specs…) or if it will be solved soon by the MONO team.

Well, here is some useful information.

Details of the Bug, and some comments about it:


To re compile MONO Sources, after do the code change:


Good Luck, Hopely this could help someone else!