Author: Ashish Datta

We’ve been using Jeff Hui’s very awesome jquery.blank plugin for sometime over at Setfive HQ. What blank() is allow you to basically move the labels for text inputs into the input themselves (to save space). We use this technique frequently for login boxes in headers since it’s easier not to have to stick in labels next to text boxes.

The problem is, you can’t use blank() on a password field since a password field won’t display clear text (obviously). To get around this, I’ve always manually stuck in a “shadow” text box next to the password field and toggled the text box or password box in order to make blank() work correctly.

Anyway, I finally got tired of doing this so I decided to patch the plugin to do this automatically. Jeff incorporated the code back into blank() and it’s available on GitHub here.

Happy coding.

So earlier today I was working on a Facebook App and wanted to use “partials” in a similar fashion as Symfony’s partials. At this point, I realized I had no idea how Symfony placed variables into the current execution scope when you do things like

include_partial("somePartial", array("foo" => $foo, "bar" => $bar));

A bit of digging led me to the extract() function in PHP.

From the documentation, “extract — Import variables into the current symbol table from an array”.

Pretty neat.

Every now and then, I’ll end up having to scrape HTML pages for some content. I know, I know, there’s like a bazillion different ways to do this, but I really like doing it in PHP so I can jack right into Symfony. Usually, I just get down and dirty with the PHP DOM and use XPath to select nodes within the document. The problem with this is that the XPath sucks and the PHP implementation sucks…alot.

But hold on, we know a selector engine that doesn’t suck! The jQuery selector engine, called Sizzle is probably one of the best CSS/DOM selector engines to use. Turns out there is a PHP port! Enter phpQuery

At its root, phpQuery is a port of the jQuery selector syntax to PHP. Additionally, phpQuery includes dozens of the jQuery traversal methods like next(), prev(), find(), and so on. It also implements the CSS3 filters like :first, :last, :eq, ect.

Anyway, if you’re tired of suffering through the PHP XPath implementation and dig jQuery then you should definitely give phpQuery a whirl.

Happy holidays everyone! Hope everyone had an awesome Christmas and is getting excited for a fun New Years Eve and then a great 2010.

Anyway, since the sun never sets on the Setfive empire I was actually doing some coding earlier when I ran across an interesting little problem. What I was looking to do was “match” a string input against a set of acceptable strings. The caveat was that the inputs might have spelling mistakes or typos. For example, an input might be “onnlinee ad” matching against [“online ad”, “video”, “news”, “online”] with the goal of matching “online ad”.

Unfortunately, you can’t simply iterate over the two strings matching letters because a single wrong letter will cause you to miss all of the rest. Remembering back to some old engineering courses I found my way over to the Hamming distance article on Wikipedia. From there, I made my way over to the Levenshtein distance article which proved extremely useful.

So, at this point I figured I wanted to minimize the Levenshtein distance and that would be my matching string. Fortunately enough, PHP has a built in function to calculate Levenshtein distances! levenshtein() The Levenshtein distance works pretty well for what I was looking to do. In addition, PHP has another built in function - similar_text() for comparing two strings. similar_text will return the number of matching characters in the two input strings.

Anyway, the only thing to be aware of is that both these functions have really bad running times. similar_text clocks in at O(n^3) where n is the length of the longest string and levenshtein runs at O(m*n) where m and n are the lengths of the input strings.

Well that’s it for now. Happy string comparing.

We were recently working on an application that required users to enter a significant amount of complex data that often meant that they had to look things up in between saves. Users kept running into the problem that their sfGuard sessions would timeout before they were able to click “Save” on the form which in turn caused them to loose all of their hard work. Obviously, this is lame so we decided to add a popup warning users that their session had expired and prompting them to login again before saving their data.

We decided to implement this by using setTimeout in Javascript to pop up a window once the user’s session had expired.

Setting the session length for a Symfony user is easy enough, open up app/config/factories.yml and add the following:

all:
  user:
    class: myUser
    param:
      timeout: 1800 # this is the default but you can change it at will (its in seconds)

As it turns out, the tricky part is how do you access this value inside the application? Un-characteristically, I couldn’t find anything in the Symfony documentation about how to access these variables. For whatever reason, sfConfig::get() doesn’t provide access to the variables in factories.yml.

In order to get that timeout value I used (inside a template):

  $userOptions = $sf_user->getOptions(); 
  $timeout = $userOptions["timeout"];

Anyway, once I figured that out the rest is pretty straightforward.

After $timeout a Javascript function opens a jQuery UI Dialog box informing the user that their session has expired and presents the standard sfGuard sign in form. I override the onSubmit of this form to perform the request via AJAX in the background (so the user doesn’t loose their data) and then if the credentials are valid the dialog closes and the user can go on their way. If the credentials are invalid, the form re-populates with any errors and the user can correct them to re-login to the app.

Hope everyone had a good Thanksgiving!