Symfony in Enterprise – Tips and Experiences

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At work I am currently tasked with redeveloping an intranet application used to track customers, products owned, support contracts, support records and all sorts of other CRM-esqué functions. The version used at the moment is a very fast Perl/MySQL/Mod_perl/Apache setup built over a few years. Its got to the point where the company needs more functionality and hacking extra functions into the current code is getting more and more difficult.

Why Symfony? Why PHP?

The current trend for “rich internet applications” is Ruby on Rails. Ruby has very powerful Object Role Modelling features that completely abstract the database from your code – no more writing SQL queries once the initial database has been set up. Database tables become class generators and rows become class references, free to be instantiated, updated and saved. Symfony is probably the closest PHP Framework to Ruby, as it utilises the Propel ORM layer (so can use almost any RDMS) and has a full Model View Controller structure. PHP runs on the vast majority of Apache installations and requires no extra software installed on the server – in addition finding skilled PHP programmers is far easier (although this might change). Symfony is also probably one of the most well documented Open Source web framework projects that I have come across, featuring a whole book written by a member of the community very close to the development team, an expansive Wiki on the project homepage and hundreds of plugins to simplify everything from AJAX to RSS feed generation.

Symfony can be used in two ways – through config files (text files defined using YAML, a simple markup language) which are passed to Generators to create the final scripts, or by manually coding the actions and pages. In reality, a combination of the two will be used. Tweaking the included Administration Generator will yield respectable results for the standard CRUD (Create, Read, Update, Delete) functions and it is extremely simple to create modules and actions with the included command-line tool that creates skeleton templates for you to use.

No longer do you have to plug in debugging tools (such as the Xdebug php extension) to get decent errors and stack traces when your application fails – Symfony provides a development view of your application that will output extremely useful information (such as execution time, a list of all SQL queries made and globals) right in the page outputted to your browser. Debugging the application I’ve been working has been as easy as that of a desktop app (coming from my experience of Visual Studio) – Symfony will work in conjunction with many PHP debugging extensions for further information if you need it (I haven’t).

Plus, Symfony is good enough for Yahoo to use it for a 20 Million user app, Yahoo Bookmarks!

Results

I’ve been working alone for a month on the project and what strikes me is the huge amount of already achieved with no prior experience of Symfony:

  • A complete database redesign using the excellent MySQL Workbench. Adding many-to-many relationships where there were none before requires a good deal of thought but the results when the ORM classes are generated by Propel in Symfony are well worth the effort
  • Database migration handled by the CLI features of Symfony. One command will generate a .php file you can run at the command line (or cron job) with automatic access to all the features of your main application. Where the database had been vastly redesigned to support relationships, custom migration code had to be written (but where tables have not changed, you can copy table data directly in one line of manual SQL). The migration script takes about half an hour to run (approx. 3,000,000 records).
  • User security and session support, timeouts etc
  • Full creation and editing of all the major record types with administration control panels
  • AJAX views and manipulation of information with per-user rearrangeable panels ala iGoogle
  • Full filtering functions for searches with auto-paginated results (soon with Excel export)
  • Global per-user filters that effect all searches
  • …and lots of other actions specific to the application

Tips

Some advice to newcomers to Symfony from my experience:

  • Don’t rewrite the wheel. Use the plugins available and tweak them if necessary.
  • Use the Admin Generator, don’t fight it. Instead of writing custom create/edit/list actions when the Administration Generator does not meet your requirements (or altering the CSS won’t help), override templates with per-module versions of your own. Even better is creating a new Generator all together (although it is a headache writing PHP code that writes PHP code!) – check out the sfAdvancedAdminGenerator plugin for inspiration.
  • Don’t worry too much about performance especially if your application is running a bit sluggish on your local machine. On a proper server with a production installation of Apache and MySQL, the application I thought was a bit slow flew given the chance. You can optimise later.
  • Don’t be scared of upgrading – I went up a symfony version during production without a hitch and without a change in my code (from 1.0 to 1.1 this will be different)
  • Use a decent IDE. I use PDT Eclipse and it definitely speeds up development. You will frequently have to edit several files at once so at least use a text editor with tabs.
  • Read the book! I can’t stress this one enough. It is extremely well written and is available for free on the website.

I’ll post some more impressions and a brief postmortem when the project is finished.

Vista net problems? Disable auto-tuning

I have been having a problem where I would get “This page cannot be displayed” errors the first time I tried to access a website. The odd thing was that hitting Refresh would solve the problem and I would get through to the site immediately. At first, I thought it was a DNS problem due to the Internet Connection Sharing setup, but turns out it is Vista messing around with the net connection with a process called “Receive Window Auto-Tuning” (this alters the size of the packets on your network based on network conditions).

To turn this off, fire up an elevated command prompt window and type in “netsh interface tcp set global autotuninglevel=disabled” without the quotes. This solved all the problems I was having with my net connection in Vista SP1. Strange.

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XNA2.0 Dependency checking

After a lot of trial and error using Process Monitor and Virtual PC, I have finally sussed out exactly what XNA2.0 games on Windows need to run. The requirements are slightly different to XNA 1 games.

Direct X runtimes

There are four files that need to be installed in the system32 folder for XNA to initialise properly. They are:

  • xinput1_3.dll
  • x3daudio1_3.dll
  • d3dx9_31.dll, and
  • xactengine2_9.dll

The first three can be placed alongside the application exe and then load fine, but xactengine2_9.dll does not load this way for some reason, and has to be present in the system directory. Distributing these files alongside the application breaks the DirectX EULA, so they have to be installed using dxsetup.exe.

To check the presence in your XNA game, just put this code in Program.cs before game.Run() is called:

bool HasAllPrereqs = true;
// check all the required files, if any missing, return false
if (!System.IO.File.Exists(System.Environment.SystemDirectory 
    + "\\xactengine2_9.dll")) HasAllPrereqs = false;
if (!System.IO.File.Exists(System.Environment.SystemDirectory 
    + "\\d3dx9_31.dll")) HasAllPrereqs = false;
if (!System.IO.File.Exists(System.Environment.SystemDirectory 
    + "\\x3daudio1_2.dll")) HasAllPrereqs = false;
if (!System.IO.File.Exists(System.Environment.SystemDirectory 
    + "\\xinput1_3.dll")) HasAllPrereqs = false;

If HasAllPrereqs is false after those lines, exit the application before it crashes horribly when XNA tries to initialise.

Visual C++ 2005 SP1 runtimes

Even a fresh Vista install doesn’t have these. They are provided when updating Visual Studio 2005 to SP1, or installing SP1 of the .Net Framework 2.0. However, Vista comes with SP0 of .Net 2.0, meaning 99% of machines you come across will be lacking what XNA 2.0 needs. There is a 2.5MB standalone installer on the MS download site here which installs what you need even on .Net 2.0 SP0 machines. .Net 3.5 installs Net 2.0 SP1.

So if any of the following are installed, we safely have the right Visual C++ 2005 runtimes:

  • .NET Framework 2.0 SP1
  • .NET Framework 3.5
  • Visual C++ 2005 SP1 Redistributable

By looking up the product codes in the registry, we can also check at runtime if we have the runtimes (again, before game.Run()):

[DllImport("msi.dll")]
public static extern Int32 MsiQueryProductState(string szProduct);

…goes before the main application entry point, and

bool vccOK = false;
// check for VC++ 2005 SP1 redist (very rare in the wild)
if (MsiQueryProductState(
"{7299052b-02a4-4627-81f2-1818da5d550d}") == 5) vccOK = true;
// check for .NET Framework 2.0 SP1
if (MsiQueryProductState(
"{2FC099BD-AC9B-33EB-809C-D332E1B27C40}") == 5) vccOK = true;
// check for .NET Framework 3.5 (includes 2.0 SP1)
if (MsiQueryProductState(
"{B508B3F1-A24A-32C0-B310-85786919EF28}") == 5) vccOK = true;

If vccOK is still false, exit the application before you call game.Run().