Hope everyone is having a fantastic 4th of July. Make sure to drink some brews and eat some BBQ!
Hope everyone is having a fantastic 4th of July. Make sure to drink some brews and eat some BBQ!
Recently on a project I had a situation where I was using the Symfony2 forms component without an entity. In addition to each field’s constraints, I needed to something similar to symfony 1.4’s conditional validator so that I could make sure that the form on the whole was valid. There are a bunch of docs out there on how to use callback functions on an entity to do this, however I didn’t see much on how to get the entire form that has no entity to do a callback. After reading some of the source code, found that you can set up some ‘form level’ constraints in the setDefaultOptions method. So it will look something like this:
You pass the Callback constraint an array methods which it can call. If you pass one of those methods is an array it is parsed as class::method. In my case by passing $this it uses the currently instantiated form, rather than trying to call the method statically.
From there you can do something like this:
The first parameter is the form’s data fields. From there you can add global level errors to the form, such as if a combination of fields are not valid.
Good luck out there.
We’re always on the hunt for talented LAMP developers and as a consequence we end up evaluating a decent amount of fairly diverse PHP code. We always ask potential employees for a code sample so that we can get a sense of their style and generally make sure they have their heads screwed on right. Because of this, we’ve been evaluating PHP samples from everything from Drupal modules, to batch processing scripts, and even “hardware hacks”.
During this process, one of the issues we’ve had is coming up with an objective rubric to evaluate the relative skill of a PHP developer. Although there are several broad criteria for evaluating code, I’ve been interested in coming up with PHP-centric benchmarks since they’re more directly applicable. Here’s a list of criteria that we’ve been working on to help us identify how familiar an engineer is with PHP.
Unfortunately, it’s sometimes easier to spot negative signals so here are a few PHP specific “code smells” we’ve identified.
Often, inexperienced engineers won’t search for standard functions that’ll do exactly what they’re looking for. Not always a bad thing but it’s a sign of inexperience. An example would be:
This one isn’t really PHP specific but we’ve noticed it a couple of times anyway. We’ll often see code that looks something like:
As you can see, the code returns all the results and then evaluates the criteria as opposed to passing the selection criteria to the ORM or SQL.
Due to PHP’s global keyword it’s unfortunately really easy to throw encapsulation to the wind and just make everything a global. Because of that, we’ve seen code that looks like:
What we look for next is usually positive signals that an engineer is generally familiar with PHP. These are generally things you’d pick up after you’ve written a fair amount of PHP.
I know this one will be controversial, but my sense is that if an engineer implements __toString() somewhere in PHP they probably have a decent familiarity with the language since its something you have to “seek out”. A canonical example would be something like:
Output buffering is a bit exotic but it’s indispensable when building web apps without a framework. It also certainly demonstrates a level of familiarity with PHP. A good example would be capturing output from a template and returning it inside some JSON:
Finally, the last couple of things we’ve been looking for are “exotic” techniques that really demonstrate that someone “gets” PHP. Granted, some (most?) of these are bad ideas in production they do convey a certain level of understanding.
Since PHP relies so heavily on arrays, building classes that implement the ArrayAccess interface makes them work more naturally in PHP and definitely demonstrates a strong level of familiarity with the language. An example would be:
Although, using any of these in production is questionable at best, they undeniably do convey a sense that whoever used them knows their way around PHP. An example (from the documentation) would be:
Anyway, like everything I’d take this list with a big grain of salt. We’d also love any input or feedback.
Recently we were getting ready to deploy a new project which functions only over SSL. The project is deployed on AWS using the Elastic Load Balancers (ELB). We have the ELB doing the SSL termination to reduce the load on the server and to help simply management of the SSL certs. Anyways the the point of this short post. One of the developers noticed that on some of the internal links she kept getting a link something like “https://dev.app.com:80/….”, it was properly generating the link to HTTPS but then specify port 80. Of course your browser really does not like that as its conflicting calls of port 80 and 443. After a quick look into the project we found that we had yet to enable the proxy headers and specify the proxy(s), it was we had to turn on `trust_proxy_headers`. However, doing this did not fix the issue. You must in addition to enable the headers specify which ones you trust. This can be easily done via the following:
Here is a very simple example of how you could specify them. You just let it know the IP’s of the proxy(s) and it will then properly generate your links.
You can read up on this more in the Symfony documentation on trusting proxies.
Anyways just wanted to put throw this out there incase you see this and realize you forgot to configure the proxy in your app!
Earlier in the week, I was looking to customize how the Bootstrap typeahead() plugin was rendering the autocomplete options. Surprisingly, looking at the options listed on the plugin there is no way to specify a custom renderer function. Poking around a bit, I ran across this pull request on GitHub it looks like changes to the typehead() plugin have been tabled since it’s going to be replaced in Bootstrap 3.0 anyway.
I didn’t really want to customize our version of Bootstrap for a single page so I went on the hunt looking for a way to customize the renderer without modifying the plugin. Looking at how the typeahead() plugin is instantiated I noticed that a reference to the “Typeahead()” object with the render() method is actually stored using data() for the element it’s activated on. Because of that, it’s actually relatively straightforward to just overwrite the render() method on the specific element that you’ve activated typeahead() on.
The code I ended up with basically looks like:
Anyway, just a fun tidbit. Questions or comments welcome as always.