The difference between M and D function in thinkphp

The difference between M and D functions in thinkphp
Reference Source: http://blog.csdn.net/siren0203/archive/2010/10/29/5974415.aspx

Two have something in common. are used to instantiate objects:

But the two are different when used ... Why??

First look at the code

function M

function M ($name = ', $class = ' Model ')   {       static $_model = Array ();       if (!isset ($_model[$name. '_' . $class])           //default is the  new Model ($name)           $_model[$name. '_' . $class] = new $class ($name);           Returns a $name of the instantiated object       return $_model[. '_' . $class];   }  

$_model[$name. '_' . $class] = new $class ($name);

The default is the new Model ($name)

Other words MThe object returned is the model

If $name is not empty then the meaning of $name is the name of the table representing the database (this is said later)

A model object is instantiated dynamically by instantiating the model method directly (Thinkphp base class). even if the corresponding model file does not exist

and look at the D function .

function D ($name = ", $app =") {Static $_model = array ();        if (empty ($name))//$name null action is equivalent to function m ();    return new Model;    if (empty ($app))//default module name is defined in common/convention.php =@ $app = C (' Default_app ');    If an object already exists, return directly to the IF (Isset ($_model[$app. $name])) return $_model[$app. $name];    $OriClassName = $name;    If the $name parameter is passed with @.**. Module name, if (Strpos ($name, '. '))        {$array = explode ('. ', $name);        $name = module Name $name = Array_pop ($array); $className = $name.        ' Model '; Import the file where the model module is imported ($app. '. Model. '. Implode ('. ', $array). '.' .    $className); }//import directly else {$className = $name.        ' Model '; Import ($app. '. Model. '.    $className);    }//Instantiate object returns if (Class_exists ($className)) {$model = new $className ();    } else {$model = new model ($name);    } $_model[$app. $OriClassName] = $model; return $model;} 

The specific comments are already in the code.

In contrast, we should be able to see ...

the D function instantiates theLib/model the following module for your current project

Returns the object of the instantiated model directly if the module does not exist (meaning is the same as the M () function)

and M returns only the object that instantiated the model. Its $name parameter handles the operation of the database as the table name of the database

Popular Point, D is to instantiate a model file based model, and M is a direct instantiation of the model method (thinkphp base class) to dynamically instantiate a model object, even if the corresponding model file does not exist.

In a more popular sense, it is:
the M instantiation parameter is the table name of the database.
d instantiates a model file that you set up under the Models folder yourself.

1/F Ninedoors 2011-10-23

This man, there is a problem, it feels very strange, but do not know why.
When I use the thinkphp framework to get the data encoding in the database and return the XML,
found that if the acquisition of the database using the D method, the output of the XML in front of a few more spaces, this does not know why.
Instead of using the M method, the space is gone.
Hope to advise.
[Email protected]

2 floor again every landscape 2011-10-31

Ninedoors wrote

This man, there is a problem, it feels very strange, but do not know why.
When I use the thinkphp framework to get the data encoding in the database and return the XML,
found that if the acquisition of the database using the D method, the output of the XML in front of a few more spaces, this does not know why.
Instead of using the M method, the space is gone.
Hope to advise.
[Email protected]

This is not the case, but you can filter out these spaces with functions such as trim or regular expressions.

