I have never heard that described as a "fluent interface" before, but you'd
probably like jQuery. :-) It's a javascript library that uses much the same
concept, although it refers to it as "function chaining". It also operates
on multiple objects simultaneously, which is even niftier.
On Thursday 12 April 2007 12:37 pm, Tim Stiles wrote:
> I suppose I should have summarized what I learned from that
> experiment, putting myself more squarely on topic: Simply put, a
> Fluent interface let me move from
>
> $_input->addCheck('Integer');
> $_input->addCheck('Range',3,9);
> $_input->addCheck('NonEmpty');
>
> to
>
> $_input->addCheck('Integer')
> ->addCheck('Range',3,9)
> ->addCheck('NonEmpty');
>
> with almost no effort. Not a huge timesaver, but I kept it in
> because I find the necessary code that I'll use repeatedly to be less
> cluttered and easier to read. Less experienced developers who will
> have to work with my code felt the same way. It just feels like less
> labor. And as a solution, it suited this problem well, mirroring how
> most people mentally approached the issue - making it easier for them
> to understand the code at a glance.
>
> I elaborated on that problem because it was specifically the nature
> of the problem that led me to Fluent interfaces as being part of the
> solution. I needed to set up a complex configuration within the
> object, but needed only a very simple response from it. Like others
> pointed out, a SQL query is a very simple thing, but building one may
> involve many seemingly simple steps that occur in no prescribed
> particular order, and you don't need the result until the
> configuration is complete. Fluent interfaces can hide complexity.
>
>
>
> 1) Fluent interfaces seem to work best when most of your methods
> alter the internal characteristics of an object. Setting properties,
> not Getting them. You can't really use a fluent interface when you
> actually NEED a specific response from your method: they work by
> returning a reference to the object itself instead of returning a
> value - that way, the response they deliver is set up and ready to
> receive a new, unrelated method call. You can combine the fluent
> with the conventional, but then you have to remember that any non-
> fluent call must occur last in a string of requests. I could have
> easily written:
>
> $test = $_input->addCheck('Integer')
> ->addCheck('Range',3,9)
> ->addCheck('NonEmpty')
> ->check('4.97');
> if($test)? ...
>
> but I found it more legible to stay conventional when using non-
> fluent methods.
>
> Basically, if you have configuration processes that often need to be
> called sequentially, but not always in the same sequence, Fluent
> interfaces can smooth the rough edges.
>
>
>
> 2) Fluent interfaces probably work better with thrown exceptions than
> they do with error notices. If you generate a non-fatal error in the
> middle of a string of fluent method calls, how do you cope with it?
> Return the object anyway and let the next method continue? Not return
> the object and get a new error because your error message can't
> accept a method call? Bail out at the point of error within your
> method instead of pointing where the error was caused? Exceptions
> move the error handling outside of the predicted flow of the fluent
> interface, making them easier to deal with. Your errors represent
> what actually went wrong instead of being a side-effect or symptom of
> something that went wrong earlier in the process.
>
>
> To sum up, Fluent interfaces seem to be a great solution when
> combined with a certain set of well-defined problems and practices.
> PHP5 makes them even more useful. They save some keystrokes, they
> can improve code legibility, they can make PHP code more intuitive
> for people who weren't the ones who created it. I don't think they
> make code execution any faster (or slower, for that matter). It's
> worth knowing about them, but they probably shouldn't change your day
> to day practices. As with most techniques, it becomes a matter of
> knowing when to apply this particular tool.
>
> Tim Stiles,
> WatchMaker,
> Icomex.com
> DallasPHP.org
--
Larry Garfield AIM: LOLG42
larry@xxxxxxxxxxxxxxxx ICQ: 6817012
"If nature has made any one thing less susceptible than all others of
exclusive property, it is the action of the thinking power called an idea,
which an individual may exclusively possess as long as he keeps it to
himself; but the moment it is divulged, it forces itself into the possession
of every one, and the receiver cannot dispossess himself of it." -- Thomas
Jefferson
--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php
