Blade шаблоны
Introduction
Blade is the simple, yet powerful templating engine provided with Laravel. Unlike other popular PHP templating engines, Blade does not restrict you from using plain PHP code in your views. In fact, all Blade views are compiled into plain PHP code and cached until they are modified, meaning Blade adds essentially zero overhead to your application. Blade view files use the .blade.php
file extension and are typically stored in the resources/views
directory.
Template Inheritance
Defining A Layout
Two of the primary benefits of using Blade are template inheritance and sections. To get started, let's take a look at a simple example. First, we will examine a "master" page layout. Since most web applications maintain the same general layout across various pages, it's convenient to define this layout as a single Blade view:
As you can see, this file contains typical HTML mark-up. However, take note of the @section
and @yield
directives. The @section
directive, as the name implies, defines a section of content, while the @yield
directive is used to display the contents of a given section.
Now that we have defined a layout for our application, let's define a child page that inherits the layout.
Extending A Layout
When defining a child view, use the Blade @extends
directive to specify which layout the child view should "inherit". Views which extend a Blade layout may inject content into the layout's sections using @section
directives. Remember, as seen in the example above, the contents of these sections will be displayed in the layout using @yield
:
In this example, the sidebar
section is utilizing the @parent
directive to append (rather than overwriting) content to the layout's sidebar. The @parent
directive will be replaced by the content of the layout when the view is rendered.
Contrary to the previous example, this
sidebar
section ends with@endsection
instead of@show
. The@endsection
directive will only define a section while@show
will define and immediately yield the section.
The @yield
directive also accepts a default value as its second parameter. This value will be rendered if the section being yielded is undefined:
Blade views may be returned from routes using the global view
helper:
Displaying Data
You may display data passed to your Blade views by wrapping the variable in curly braces. For example, given the following route:
You may display the contents of the name
variable like so:
Blade
{{ }}
statements are automatically sent through PHP'shtmlspecialchars
function to prevent XSS attacks.
You are not limited to displaying the contents of the variables passed to the view. You may also echo the results of any PHP function. In fact, you can put any PHP code you wish inside of a Blade echo statement:
Displaying Unescaped Data
By default, Blade {{ }}
statements are automatically sent through PHP's htmlspecialchars
function to prevent XSS attacks. If you do not want your data to be escaped, you may use the following syntax:
Be very careful when echoing content that is supplied by users of your application. Always use the escaped, double curly brace syntax to prevent XSS attacks when displaying user supplied data.
Rendering JSON
Sometimes you may pass an array to your view with the intention of rendering it as JSON in order to initialize a JavaScript variable. For example:
However, instead of manually calling json_encode
, you may use the @json
Blade directive. The @json
directive accepts the same arguments as PHP's json_encode
function:
You should only use the
@json
directive to render existing variables as JSON. The Blade templating is based on regular expressions and attempts to pass a complex expression to the directive may cause unexpected failures.
HTML Entity Encoding
By default, Blade (and the Laravel e
helper) will double encode HTML entities. If you would like to disable double encoding, call the Blade::withoutDoubleEncoding
method from the boot
method of your AppServiceProvider
:
Blade & JavaScript Frameworks
Since many JavaScript frameworks also use "curly" braces to indicate a given expression should be displayed in the browser, you may use the @
symbol to inform the Blade rendering engine an expression should remain untouched. For example:
In this example, the @
symbol will be removed by Blade; however, {{ name }}
expression will remain untouched by the Blade engine, allowing it to instead be rendered by your JavaScript framework.
The @
symbol may also be used to escape Blade directives:
The @verbatim Directive
If you are displaying JavaScript variables in a large portion of your template, you may wrap the HTML in the @verbatim
directive so that you do not have to prefix each Blade echo statement with an @
symbol:
Control Structures
In addition to template inheritance and displaying data, Blade also provides convenient shortcuts for common PHP control structures, such as conditional statements and loops. These shortcuts provide a very clean, terse way of working with PHP control structures, while also remaining familiar to their PHP counterparts.
If Statements
You may construct if
statements using the @if
, @elseif
, @else
, and @endif
directives. These directives function identically to their PHP counterparts:
For convenience, Blade also provides an @unless
directive:
In addition to the conditional directives already discussed, the @isset
and @empty
directives may be used as convenient shortcuts for their respective PHP functions:
Authentication Directives
The @auth
and @guest
directives may be used to quickly determine if the current user is authenticated or is a guest:
If needed, you may specify the authentication guard that should be checked when using the @auth
and @guest
directives:
Section Directives
You may check if a section has content using the @hasSection
directive:
You may use the sectionMissing
directive to determine if a section does not have content:
Environment Directives
You may check if the application is running in the production environment using the @production
directive:
Or, you may determine if the application is running in a specific environment using the @env
directive:
Switch Statements
Switch statements can be constructed using the @switch
, @case
, @break
, @default
and @endswitch
directives:
Loops
In addition to conditional statements, Blade provides simple directives for working with PHP's loop structures. Again, each of these directives functions identically to their PHP counterparts:
When looping, you may use the loop variable to gain valuable information about the loop, such as whether you are in the first or last iteration through the loop.
When using loops you may also end the loop or skip the current iteration:
You may also include the condition with the directive declaration in one line:
The Loop Variable
When looping, a $loop
variable will be available inside of your loop. This variable provides access to some useful bits of information such as the current loop index and whether this is the first or last iteration through the loop:
If you are in a nested loop, you may access the parent loop's $loop
variable via the parent
property:
The $loop
variable also contains a variety of other useful properties:
Property
Description
$loop->index
The index of the current loop iteration (starts at 0).
$loop->iteration
The current loop iteration (starts at 1).
$loop->remaining
The iterations remaining in the loop.
$loop->count
The total number of items in the array being iterated.
$loop->first
Whether this is the first iteration through the loop.
$loop->last
Whether this is the last iteration through the loop.
$loop->even
Whether this is an even iteration through the loop.
$loop->odd
Whether this is an odd iteration through the loop.
$loop->depth
The nesting level of the current loop.
$loop->parent
When in a nested loop, the parent's loop variable.
Comments
Blade also allows you to define comments in your views. However, unlike HTML comments, Blade comments are not included in the HTML returned by your application:
PHP
In some situations, it's useful to embed PHP code into your views. You can use the Blade @php
directive to execute a block of plain PHP within your template:
While Blade provides this feature, using it frequently may be a signal that you have too much logic embedded within your template.
The @once
Directive
@once
DirectiveThe @once
directive allows you to define a portion of the template that will only be evaluate once per rendering cycle. This may be useful for pushing a given piece of JavaScript into the page's header using stacks. For example, if you are rendering a given component within a loop, you may wish to only push the JavaScript to the header the the first time the component is rendered:
Forms
CSRF Field
Anytime you define an HTML form in your application, you should include a hidden CSRF token field in the form so that the CSRF protection middleware can validate the request. You may use the @csrf
Blade directive to generate the token field:
Method Field
Since HTML forms can't make PUT
, PATCH
, or DELETE
requests, you will need to add a hidden _method
field to spoof these HTTP verbs. The @method
Blade directive can create this field for you:
Validation Errors
The @error
directive may be used to quickly check if validation error messages exist for a given attribute. Within an @error
directive, you may echo the $message
variable to display the error message:
You may pass the name of a specific error bag as the second parameter to the @error
directive to retrieve validation error messages on pages containing multiple forms:
Components
Components and slots provide similar benefits to sections and layouts; however, some may find the mental model of components and slots easier to understand. There are two approaches to writing components: class based components and anonymous components.
To create a class based component, you may use the make:component
Artisan command. To illustrate how to use components, we will create a simple Alert
component. The make:component
command will place the component in the App\View\Components
directory:
The make:component
command will also create a view template for the component. The view will be placed in the resources/views/components
directory.
Manually Registering Package Components
When writing components for your own application, components are automatically discovered within the app/View/Components
directory and resources/views/components
directory.
However, if you are building a package that utilizes Blade components, you will need to manually register your component class and its HTML tag alias. You should typically register your components in the boot
method of your package's service provider:
Once your component has been registered, it may be rendered using its tag alias:
Displaying Components
To display a component, you may use a Blade component tag within one of your Blade templates. Blade component tags start with the string x-
followed by the kebab case name of the component class:
If the component class is nested deeper within the App\View\Components
directory, you may use the .
character to indicate directory nesting. For example, if we assume a component is located at App\View\Components\Inputs\Button.php
, we may render it like so:
Passing Data To Components
You may pass data to Blade components using HTML attributes. Hard-coded, primitive values may be passed to the component using simple HTML attributes. PHP expressions and variables should be passed to the component via attributes that are prefixed with :
:
You should define the component's required data in its class constructor. All public properties on a component will automatically be made available to the component's view. It is not necessary to pass the data to the view from the component's render
method:
When your component is rendered, you may display the contents of your component's public variables by echoing the variables by name:
Casing
Component constructor arguments should be specified using camelCase
, while kebab-case
should be used when referencing the argument names in your HTML attributes. For example, given the following component constructor:
The $alertType
argument may be provided like so:
Component Methods
In addition to public variables being available to your component template, any public methods on the component may also be executed. For example, imagine a component that has a isSelected
method:
You may execute this method from your component template by invoking the variable matching the name of the method:
Using Attributes & Slots Inside The Class
Blade components also allow you to access the component name, attributes, and slot inside the class's render method. However, in order to access this data, you should return a Closure from your component's render
method. The Closure will receive a $data
array as its only argument:
The componentName
is equal to the name used in the HTML tag after the x-
prefix. So <x-alert />
's componentName
will be alert
. The attributes
element will contain all of the attributes that were present on the HTML tag. The slot
element is a Illuminate\Support\HtmlString
instance with the contents of the slot from the component.
Additional Dependencies
If your component requires dependencies from Laravel's service container, you may list them before any of the component's data attributes and they will automatically be injected by the container:
Managing Attributes
We've already examined how to pass data attributes to a component; however, sometimes you may need to specify additional HTML attributes, such as class
, that are not part of the data required for a component to function. Typically, you want to pass these additional attributes down to the root element of the component template. For example, imagine we want to render an alert
component like so:
All of the attributes that are not part of the component's constructor will automatically be added to the component's "attribute bag". This attribute bag is automatically made available to the component via the $attributes
variable. All of the attributes may be rendered within the component by echoing this variable:
Echoing variables (
{{ $attributes }}
) or using directives such as@env
directly on a component is not supported at this time.
Default / Merged Attributes
Sometimes you may need to specify default values for attributes or merge additional values into some of the component's attributes. To accomplish this, you may use the attribute bag's merge
method:
If we assume this component is utilized like so:
The final, rendered HTML of the component will appear like the following:
Filtering Attributes
You may filter attributes using the filter
method. This method accepts a Closure which should return true
if you wish to retain the attribute in the attribute bag:
For convenience, you may use the whereStartsWith
method to retrieve all attributes whose keys begin with a given string:
Using the first
method, you may render the first attribute in a given attribute bag:
Slots
Often, you will need to pass additional content to your component via "slots". Let's imagine that an alert
component we created has the following markup:
We may pass content to the slot
by injecting content into the component:
Sometimes a component may need to render multiple different slots in different locations within the component. Let's modify our alert component to allow for the injection of a "title":
You may define the content of the named slot using the x-slot
tag. Any content not within a x-slot
tag will be passed to the component in the $slot
variable:
Scoped Slots
If you have used a JavaScript framework such as Vue, you may be familiar with "scoped slots", which allow you to access data or methods from the component within your slot. You may achieve similar behavior in Laravel by defining public methods or properties on your component and accessing the component within your slot via the $component
variable:
Inline Component Views
For very small components, it may feel cumbersome to manage both the component class and the component's view template. For this reason, you may return the component's markup directly from the render
method:
Generating Inline View Components
To create a component that renders an inline view, you may use the inline
option when executing the make:component
command:
Anonymous Components
Similar to inline components, anonymous components provide a mechanism for managing a component via a single file. However, anonymous components utilize a single view file and have no associated class. To define an anonymous component, you only need to place a Blade template within your resources/views/components
directory. For example, assuming you have defined a component at resources/views/components/alert.blade.php
:
You may use the .
character to indicate if a component is nested deeper inside the components
directory. For example, assuming the component is defined at resources/views/components/inputs/button.blade.php
, you may render it like so:
Data Properties / Attributes
Since anonymous components do not have any associated class, you may wonder how you may differentiate which data should be passed to the component as variables and which attributes should be placed in the component's attribute bag.
You may specify which attributes should be considered data variables using the @props
directive at the top of your component's Blade template. All other attributes on the component will be available via the component's attribute bag. If you wish to give a data variable a default value, you may specify the variable's name as the array key and the default value as the array value:
Including Subviews
Blade's @include
directive allows you to include a Blade view from within another view. All variables that are available to the parent view will be made available to the included view:
Even though the included view will inherit all data available in the parent view, you may also pass an array of extra data to the included view:
If you attempt to @include
a view which does not exist, Laravel will throw an error. If you would like to include a view that may or may not be present, you should use the @includeIf
directive:
If you would like to @include
a view if a given boolean expression evaluates to true
, you may use the @includeWhen
directive:
If you would like to @include
a view if a given boolean expression evaluates to false
, you may use the @includeUnless
directive:
To include the first view that exists from a given array of views, you may use the includeFirst
directive:
You should avoid using the
__DIR__
and__FILE__
constants in your Blade views, since they will refer to the location of the cached, compiled view.
Aliasing Includes
If your Blade includes are stored in a subdirectory, you may wish to alias them for easier access. For example, imagine a Blade include that is stored at resources/views/includes/input.blade.php
with the following content:
You may use the include
method to alias the include from includes.input
to input
. Typically, this should be done in the boot
method of your AppServiceProvider
:
Once the include has been aliased, you may render it using the alias name as the Blade directive:
Rendering Views For Collections
You may combine loops and includes into one line with Blade's @each
directive:
The first argument is the view partial to render for each element in the array or collection. The second argument is the array or collection you wish to iterate over, while the third argument is the variable name that will be assigned to the current iteration within the view. So, for example, if you are iterating over an array of jobs
, typically you will want to access each job as a job
variable within your view partial. The key for the current iteration will be available as the key
variable within your view partial.
You may also pass a fourth argument to the @each
directive. This argument determines the view that will be rendered if the given array is empty.
Views rendered via
@each
do not inherit the variables from the parent view. If the child view requires these variables, you should use@foreach
and@include
instead.
Stacks
Blade allows you to push to named stacks which can be rendered somewhere else in another view or layout. This can be particularly useful for specifying any JavaScript libraries required by your child views:
You may push to a stack as many times as needed. To render the complete stack contents, pass the name of the stack to the @stack
directive:
If you would like to prepend content onto the beginning of a stack, you should use the @prepend
directive:
Service Injection
The @inject
directive may be used to retrieve a service from the Laravel service container. The first argument passed to @inject
is the name of the variable the service will be placed into, while the second argument is the class or interface name of the service you wish to resolve:
Extending Blade
Blade allows you to define your own custom directives using the directive
method. When the Blade compiler encounters the custom directive, it will call the provided callback with the expression that the directive contains.
The following example creates a @datetime($var)
directive which formats a given $var
, which should be an instance of DateTime
:
As you can see, we will chain the format
method onto whatever expression is passed into the directive. So, in this example, the final PHP generated by this directive will be:
After updating the logic of a Blade directive, you will need to delete all of the cached Blade views. The cached Blade views may be removed using the
view:clear
Artisan command.
Custom If Statements
Programming a custom directive is sometimes more complex than necessary when defining simple, custom conditional statements. For that reason, Blade provides a Blade::if
method which allows you to quickly define custom conditional directives using Closures. For example, let's define a custom conditional that checks the current application cloud provider. We may do this in the boot
method of our AppServiceProvider
:
Once the custom conditional has been defined, we can easily use it on our templates:
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