Creating Providers to use with Zend_Tool_Framework
In general, a provider, on its own, is nothing more than the shell for a
developer to bundle up some capabilities they wish to dispatch with the
command line (or other) clients. It is an analogue to what a
"controller" is inside of your MVC application.
Basic Instructions for Creating Providers
As an example, if a developer wants to add the capability of showing
the version of a datafile that his 3rd party component is working
from, there is only one class the developer would need to implement.
Assuming the component is called My_Component, he would
create a class named My_Component_HelloProvider in a
file named HelloProvider.php somewhere on the
include_path. This class would implement
Zend_Tool_Framework_Provider_Interface, and the body of
this file would only have to look like the following:
Given that code above, and assuming the developer wishes to access
this functionality through the console client, the call would look
like this:
Advanced Development Information
The above "Hello World" example is great for simple commands, but
what about something more advanced? As your scripting and tooling
needs grow, you might find that you need the ability to accept
variables. Much like function signatures have parameters, your
tooling requests can also accept parameters.
Just as each tooling request can be isolated to a method within a
class, the parameters of a tooling request can also be isolated in a
very well known place. Parameters of the action methods of a
provider can include the same parameters you want your client to
utilize when calling that provider and action combination. For
example, if you wanted to accept a name in the above example, you
would probably do this in OO code:
The above example can then be called via the command line zf
say hello Joe. "Joe" will be supplied to the provider as
a parameter of the method call. Also note, as you see that the
parameter is optional, that means it is also optional on the command
line, so that zf say hello will still work, and default
to the name "Ralph".
Another interesting feature you might wish to implement is
pretendability. Pretendabilty is the ability
for your provider to "pretend" as if it is doing the requested
action and provider combination and give the user as much
information about what it would do without
actually doing it. This might be an important notion when doing
heavy database or filesystem modifications that the user might not
otherwise want to do.
Pretendability is easy to implement. There are two parts to this
feature: 1) marking the provider as having the ability to "pretend",
and 2) checking the request to ensure the current request was indeed
asked to be "pretended". This feature is demonstrated in the code
sample below.
_registry->getRequest()->isPretend()) {
echo 'I would say hello to ' . $name . '.';
} else {
echo 'Hello' . $name . ', from my provider!';
}
}
}
]]>