基于字符串动态创建PHP对象 [英] Dynamically create PHP object based on string

问题描述

我想基于由 MySQL 数据库中的字符串定义的类型在 PHP 中创建一个对象.数据库表具有以下列和示例数据:

I would like to create an object in PHP based on a type defined by a string in a MySQL database. The database table has columns and sample data of:

 id | type | propertyVal
----+------+-------------
  1 | foo  | lorum
  2 | bar  | ipsum

...使用 PHP 数据类型

...with PHP data types

class ParentClass {...}
class Foo extends ParentClass {private $id, $propertyVal; ...}
class Bar extends ParentClass {private $id, $propertyVal; ...} 
//...(more classes)...

仅使用一个查询，我想通过 id 选择一行并创建一个定义表的类型列的对象，而 SELECTed 行中的其他列被分配给新创建的对象.

Using only one query, I would like to SELECT a row by id and create an object of the type define the table's type column with other columns in the SELECTed row being assigned to the newly created object.

我想使用:

1. mysql_fetch_object()
2. 读取类型属性
3. 创建一个由 type 属性定义的类型的对象

但是不知道基于字符串动态创建类型的方法.如何做到这一点?

But know of no way to dynamically create a type based on a string. How does one do this?

推荐答案

但是不知道基于字符串动态创建类型的方法.如何做到这一点?

But know of no way to dynamically create a type based on a string. How does one do this?

您可以轻松自然地做到这一点:

You can do it quite easily and naturally:

$type = 'myclass';

$instance = new $type;

如果您的查询返回关联数组，您可以使用类似的语法分配属性:

If your query is returning an associative array, you can assign properties using similar syntax:

// build object
$type = $row['type'];
$instance = new $type;

// remove 'type' so we don't set $instance->type = 'foo' or 'bar'
unset($row['type']);  

// assign properties
foreach ($row as $property => $value) {
   $instance->$property = $value;
}

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