Component is the main component of the YII framework application (application). It is an instance or subclass of [yii\base\Component]. Components have three important characteristics (functions):
##·Properties
·Events
·Behaviors
Using these features alone or in combination can make the classes of the Yii framework become more Easy to use and customizable. For example, by introducing a user interaction component [yii\jui\DataPicker\data picker wigets], you can easily generate a date selection control (jquery ui date picker) in the view.use yii\jui\DatePicker;
echo DatePicker::widget([
'language' => 'ru',
'name' => 'country',
'clientOptions' => [
'dateFormat' => 'yy-mm-dd',
],
]);The properties of the DatePicker pendant are easily modified because it inherits the class [yii\base\Componet]Although the component is very powerful, its overhead is greater than that of ordinary class objects. , the reason is that components require additional memory and CPU time to process events and behaviors. If your component does not need the two characteristics (functions) of events and behaviors, you can directly inherit [yii\base\Object] , so that your component is consistent in performance (efficiency) with ordinary class objects and supports properties. To write a class that inherits [yii\base\Component] or [yii\base\Object], you need to follow the following conventions: ·Assuming that you rewrite the constructor, you must define a parameter $config as the last parameter of the constructor. This parameter is passed to the constructor of the parent class for use.
·The constructor of the parent class must be called at the end of the overridden constructor
·Suppose you rewrite [yii\base\Object: :init()|init()] method, then the init method of the parent class must be called starting from the overridden init method
For examplenamespace yii\components\MyClass;
use yii\base\Object;
class MyClass extends Object
{
public $prop1;
public $prop2;
public function __construct($param1, $param2, $config = [])
{
// ... initialization before configuration is applied
parent::__construct($config);
}
public function init()
{
parent::init();
// ... initialization after configuration is applied
}
}Follow the following example to make your Properties can be configured (initialized) when the component is created: $component = new MyClass(1, 2, ['prop1' => 3, 'prop2' => 4]);
// alternatively
$component = \Yii::createObject([
'class' => MyClass::className(),
'prop1' => 3,
'prop2' => 4,
], [1, 2]); Tip: Using [Yii::createOject()] seems more complicated, but because [Yii::createObject] is based on dependency injection implementation, so it is more powerful [yii\base\Object] class enforces the following life cycle: (1) Implement pre-initialization in the constructor, and you can set the default at this time Attribute value; (2) Configure the object through $config, and the default value can be overridden through object configuration in the constructor; (3) In [yii\base\Object::init ()|init()] method, perform initialization configuration. Routine checks and attribute normalization checks can be implemented in the init method; (4) Object method call. The first three stages are all implemented in the constructor, which means that when you get an instance of an object, it has been initialized to the appropriate state and can be used with confidence. PHP Chinese website has a large number of free Yii introductory tutorials, everyone is welcome to learn!
The above is the detailed content of What does component mean in yii2?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
How to install the Windows 10 old version component DirectPlay
Dec 28, 2023 pm 03:43 PM
Many users always encounter some problems when playing some games on win10, such as screen freezes and blurred screens. At this time, we can solve the problem by turning on the directplay function, and the operation method of the function is also Very simple. How to install directplay, the old component of win10 1. Enter "Control Panel" in the search box and open it 2. Select large icons as the viewing method 3. Find "Programs and Features" 4. Click on the left to enable or turn off win functions 5. Select the old version here Just check the box
How to implement calendar component using Vue?
Jun 25, 2023 pm 01:28 PM
Vue is a very popular front-end framework. It provides many tools and functions, such as componentization, data binding, event handling, etc., which can help developers build efficient, flexible and easy-to-maintain Web applications. In this article, I will introduce how to implement a calendar component using Vue. 1. Requirements analysis First, we need to analyze the requirements of this calendar component. A basic calendar should have the following functions: display the calendar page of the current month; support switching to the previous month or next month; support clicking on a certain day,
VSCode plug-in sharing: a plug-in for real-time preview of Vue/React components
Mar 17, 2022 pm 08:07 PM
When developing Vue/React components in VSCode, how to preview the components in real time? This article will share with you a plug-in for real-time preview of Vue/React components in VSCode. I hope it will be helpful to you!
VUE3 development basics: using extends to inherit components
Jun 16, 2023 am 08:58 AM
Vue is one of the most popular front-end frameworks currently, and VUE3 is the latest version of the Vue framework. Compared with VUE2, VUE3 has higher performance and a better development experience, and has become the first choice of many developers. In VUE3, using extends to inherit components is a very practical development method. This article will introduce how to use extends to inherit components. What is extends? In Vue, extends is a very practical attribute, which can be used for child components to inherit from their parents.
How to open the settings of the old version of win10 components
Dec 22, 2023 am 08:45 AM
Win10 old version components need to be turned on by users themselves in the settings, because many components are usually closed by default. First we need to enter the settings. The operation is very simple. Just follow the steps below. Where are the win10 old version components? Open 1. Click Start, then click "Win System" 2. Click to enter the Control Panel 3. Then click the program below 4. Click "Enable or turn off Win functions" 5. Here you can choose what you want to open
Angular components and their display properties: understanding non-block default values
Mar 15, 2024 pm 04:51 PM
The default display behavior for components in the Angular framework is not for block-level elements. This design choice promotes encapsulation of component styles and encourages developers to consciously define how each component is displayed. By explicitly setting the CSS property display, the display of Angular components can be fully controlled to achieve the desired layout and responsiveness.
Vue component practice: paging component development
Nov 24, 2023 am 08:56 AM
Vue component practice: Introduction to paging component development In web applications, the paging function is an essential component. A good paging component should be simple and clear in presentation, rich in functions, and easy to integrate and use. In this article, we will introduce how to use the Vue.js framework to develop a highly customizable paging component. We will explain in detail how to develop using Vue components through code examples. Technology stack Vue.js2.xJavaScript (ES6) HTML5 and CSS3 development environment
Vue component development: implementation method of progress bar component
Nov 24, 2023 am 08:56 AM
Vue component development: Progress bar component implementation method Preface: In Web development, the progress bar is a common UI component, often used to display the progress of operations in scenarios such as data requests, file uploads, and form submissions. In Vue.js, we can easily implement a progress bar component by customizing components. This article will introduce an implementation method and provide specific code examples. I hope it will be helpful to Vue.js beginners. Component structure and style First, we need to define the basic structure and style of the progress bar component.
