Tech stuff and randomness
My new venture, Wedu Games, is up and running. Or at least the site is as there are no games finished yet. There are a few things in development, though, including an interactive storytelling table app (that isn’t a game at all) and a stud/hold-em poker hybrid to launch on mobile and Facebook together. Everything’s being built in HTML and JavaScript with possibly a bit of Node.js for simple back-end.
In the meantime there are a few blog posts to read. Now, back to making the games again…
Slides from my presentation at the London Facebook Developer Garage last night:
With Daniel Schaffer (author of the .Net Facebook API Client) I’ve put together a Stack Overflow-type website for Facebook developer help called fbExchange.Net. It’s intended to build as a knowledge base and to be focussed more on tech than the official Facebook developer forum’s discussion format. (So hopefully the forum will be the place for “Is the Platform down?” or “What do you think of the new design?” type questions, and fbExchange.Net can be the site for “How do I…?” questions.)
For anyone who’s not familiar with the Stack Exchange model, you gain reputation by asking (good) questions, and answering them such that other people vote for your answers. For freelance developers and consultants having a high reputation can even help to bring work in. While the site’s in an early stage (“bootstrap mode”) it’s easier to gain points too, so there’s some benefit in getting in there now (hint, hint).
It’s intended to be dev-centred, but there’s no reason why it can’t cover most of the practicalities of “how do I set up a Facebook Page” etc, so feel free to create questions you know the answer to and even answer them yourself. The great thing about the system is that since it’s community moderated, and questions are tagged rather than put into categories, then the definition of “what can I ask?” is fairly broad.
I’ve had this problem before: PHP truncates results from a SQL Server text field to 4096 characters. (This is running PHP under Apache on Windows.) To save myself having to work out the right Google terms again, this is the solution: change the following in php.ini (note that ini_set doesn’t appear to work:
; Valid range 0 - 2147483647. Default = 4096. mssql.textlimit = 2147483647 ; Valid range 0 - 2147483647. Default = 4096. mssql.textsize = 2147483647
Ever since programming BASIC on the Spectrum I’d wondered why it was possible to seed a “random” number generator. But then I found I wanted to do something that would produce repeatable results, but look like a random sequence. Strangely, although JavaScript alongs you to specify a seed for Math.random() the numbers that follow aren’t a repeated sequence. I’m guessing the system clock comes into it.
So after some Googling for an equation to generate numbers I put together the following function. It works on a sequence of 2^32 numbers, in “random” order. (I believed the equation I found – I didn’t test the completeness of it, but it looks pretty random to me.) So, just call Random.next() to get a decimal between 0 and 1, or pass in a range (lower,upper) and you get a random number between the two.
var Random =
{
seed : 12345,
//Returns a random number between 0 and 1
next : function(lower,upper)
{
var maxi = Math.pow(2,32);
this.seed = (134775813 * (this.seed + 1))
% maxi;
var num = (this.seed) / maxi;
if(typeof lower!='undefined')
{
var range = upper - lower;
num *= range;
num += lower;
}
return num;
}
}
Set “Random.seed” to taste.
I wanted to have a function called after data was returned to the page from a .Net AJAX call. (The idea was to fade out when you pressed “submit” and then redraw when data came back.) It turns out there are handy handlers already there to, erm, handle this:
Sys.WebForms.PageRequestManager.getInstance() .add_beginRequest(StartRequestHandler); Sys.WebForms.PageRequestManager.getInstance() .add_endRequest(EndRequestHandler);
Those little nuggets add calls to your functions, and the functions themselves are:
function StartRequestHandler(sender,args)
{
}
function EndRequestHandler(sender, args)
{
}
Nice.
From The Daily WTF
I was thinking about how to best represent connections between people in my Six Degrees of Separation Facebook application and Paul Crabtree recommend I get in touch with Moritz Stefaner as he had something that would fit very nicely indeed.
And he most certainly did; the relation browser was exactly what I wanted to do, but better. If you have a Facebook account, install the application, and go to the Show Network tab you’ll see what I mean.
This piece of SQL is perfect for finding which query is running at any particular time, especially if you want to find what it is that’s running very slowly.
sp_who2
This should return a list of what’s running, including process ids (in the first column). Find out what’s causing all the trouble and enter it’s id after spid = below:
DECLARE @Handle binary(20) SELECT @Handle = sql_handle FROM master.dbo.sysprocesses WHERE spid = 55 SELECT * FROM ::fn_get_sql(@Handle)
Everyone’s been either copying and pasting or writing from scratch some code to add “Invite friends” to their Facebook apps, but now there’s a simple tag that they’ve provided. It’s currently in beta and, knowing Facebook, is bound to change and break everything a few times, but it’s very easy to use:
" image="http://apps.exponetic.com/itrust/ _img/iTrust-logo-magenta-small.gif">
(Note the slightly dodgy tag inside the content attribute.)
We’re now using it at Exponetic on our second Facebook application, called iTrust.
Exponetic, Facebook developers in London
iTrust
Six degrees of separation