common constant variables in Zend Framework - zend-framework

Question

Where is the best place to create a class that contain all the application constant variables ?
is it :
- Bootstrap
- In the Application Common library
for example :
1- When i retrieve an image name from a database if this record doesnt have an image , i want to put a default value somewhere so i can use it in my models
** a constants that i use in all my application so if i change it , i dont want to go back to all in my code and change it everywhere

Answer 1

application.ini is the best place for example define some constant there
constants.PUBLIC_PATH = APPLICATION_PATH "/../public/"
constants.THEME = blue
Then in your bootstrap do
protected function setConstants($constants)
{
foreach($constants as $name => $value)
{
if(!defined($name))
define($name, $value);
}
}
ZF take 'constants' from config and call setConstants method in your bootstrap passing all lines prefixed by constants hence its an array .

Answer 2

I try not use constants and prefer class constants over global constants. However, when constants are unavoidable, for whatever reason, I go with .ini config file and Bootstrap/library/model class constants.
An example of .ini config constants
(assumes default zf project structure)
application/configs/application.ini
constants.MESSAGE_1 = "Message 1"
constants.MESSAGE_2 = "Message 2"
Bootstap.php
class Bootstrap extends Zend_Application_Bootstrap_Bootstrap
{
protected function _initConstants()
{
$options = $this->getOption('constants');
if (is_array($options)) {
foreach($options as $key => $value) {
if(!defined($key)) {
define($key, $value);
}
}
}
}
// ...
}
Example usage in controller:
class IndexController extends Zend_Controller_Action
{
public function indexAction()
{
$this->view->message1 = MESSAGE_1;
$this->view->message2 = MESSAGE_2;
}
}
I would extend on the above to allow configuration of how your constants are defined. For example you may want all constants UPPERCASED or not, and allow or disallow already defined constants, so:
application/configs/application.ini
constants.forceUppercase = 1
constants.allowAlreadyDefined = 1
constants.set.message_1 = "Message 1"
constants.set.message_2 = "Message 2"
Bootstrap:
protected function _initConstants()
{
$options = $this->getOption('constants');
if (isset($options['set']) && is_array($options['set'])) {
if (isset($options['forceUppercase'])
&& (bool) $options['forceUppercase']) {
$options['set'] = array_change_key_case($options['set'], CASE_UPPER);
}
$allowAlreadyDefined = false;
if (isset($options['allowAlreadyDefined'])
&& (bool) $options['allowAlreadyDefined']) {
$allowAlreadyDefined = true;
}
foreach($options['set'] as $key => $value) {
if (!defined($key)) {
define($key, $value);
} elseif (!$allowAlreadyDefined) {
throw new InvalidArgumentException(sprintf(
"'%s' already defined!", $key));
}
}
}
}
Bootstrap class constants
Could be your own library, or model class, etc., it depends.
In the bootstrap:
class Bootstrap extends Zend_Application_Bootstrap_Bootstrap
{
const MESSAGE_CONSTANT = "Hello World";
// ...
}
Example usage in controller:
class IndexController extends Zend_Controller_Action
{
public function indexAction()
{
$this->view->message = Bootstrap::MESSAGE_CONSTANT;
}
}