Switch in Laravel 5 - Blade

问题:

How can I use switch in blade templates? When I used:

@switch($login_error)
    @case(1)
        `E-mail` input is empty!
        @break
    @case(2)
        `Password` input is empty!
        @break
@endswitch

in result I see this text as plaintext. I prefer to use switch in few piece of code because it's more clean for me than when I using if.

But if it's not possible just write it.

回答1:

Update 2018 version

Since Laravel 5.5 the @switch is built into the Blade. Use it as shown below.

@switch($login_error)
    @case(1)
        <span> `E-mail` input is empty!</span>
        @break

    @case(2)
        <span>`Password` input is empty!</span>
        @break

    @default
        <span>Something went wrong, please try again</span>
@endswitch

Older Answer

Unfortunately Laravel Blade does not have switch statement. You can use Laravel if else approach or use use plain PHP switch. You can use plain PHP in blade templates like in any other PHP application. Starting from Laravel 5.2 and up use @php statement.

Option 1:

@if ($login_error == 1)
    `E-mail` input is empty!
@elseif ($login_error == 2)
    `Password` input is empty!
@endif

回答2:

You can just add these code in AppServiceProvider class boot method.

Blade::extend(function($value, $compiler){
        $value = preg_replace('/(\s*)@switch\((.*)\)(?=\s)/', '$1<?php switch($2):', $value);
        $value = preg_replace('/(\s*)@endswitch(?=\s)/', '$1endswitch; ?>', $value);
        $value = preg_replace('/(\s*)@case\((.*)\)(?=\s)/', '$1case $2: ?>', $value);
        $value = preg_replace('/(?<=\s)@default(?=\s)/', 'default: ?>', $value);
        $value = preg_replace('/(?<=\s)@breakswitch(?=\s)/', '<?php break;', $value);
        return $value;
    });

then you can use as:

@switch( $item )
    @case( condition_1 )
        // do something
    @breakswitch
    @case( condition_2 )
        // do something else
    @breakswitch
    @default
        // do default behaviour
    @breakswitch
@endswitch

Enjoy It~

回答3:

IN LARAVEL 5.2 AND UP:

Write your usual code between the opening and closing PHP statements.

@php
switch (x) {
    case 1:
        //code to be executed
        break;
    default:
        //code to be executed
}
@endphp

回答4:

In Laravel 5.1, this works in a Blade:

<?php
    switch( $machine->disposal ) {
        case 'DISPO': echo 'Send to Property Disposition'; break;
        case 'UNIT':  echo 'Send to Unit'; break;
        case 'CASCADE': echo 'Cascade the machine'; break;
        case 'TBD':   echo 'To Be Determined (TBD)'; break;
    }
?>

回答5:

This is now built in Laravel 5.5 https://laravel.com/docs/5.5/blade#switch-statements

回答6:

You can extend blade like so:

    Blade::directive('switch', function ($expression) {
        return "<?php switch($expression): ?>";
    });
    Blade::directive('case', function ($expression) {
        return "<?php case $expression: ?>";
    });
    Blade::directive('break', function () {
        return "<?php break; ?>";
    });
    Blade::directive('default', function () {
        return "<?php default: ?>";
    });
    Blade::directive('endswitch', function () {
        return "<?php endswitch; ?>";
    });

You can then use the following:

@switch($test)
@case(1)
        Words
@break
@case(2)
    Other Words
    @break
@default
    Default words
@endswitch

However do note the warnings in : http://php.net/manual/en/control-structures.alternative-syntax.php

If there is any whitespace between the switch(): and the first case then the whole code block will fail. That is a PHP limitation rather than a blade limitation. You may be able to bypass it by forcing the normal syntax e.g.:

Blade::directive('switch', function ($expression) {
    return "<?php switch($expression) { ?>";
});
Blade::directive('endswitch', function ($) {
    return "<?php } ?>";
});

But this feels a bit wrong.

回答7:

To overcome the space in 'switch ()', you can use code :

Blade::extend(function($value, $compiler){
    $value = preg_replace('/(\s*)@switch[ ]*\((.*)\)(?=\s)/', '$1<?php switch($2):', $value);
    $value = preg_replace('/(\s*)@endswitch(?=\s)/', '$1endswitch; ?>', $value);
    $value = preg_replace('/(\s*)@case[ ]*\((.*)\)(?=\s)/', '$1case $2: ?>', $value);
    $value = preg_replace('/(?<=\s)@default(?=\s)/', 'default: ?>', $value);
    $value = preg_replace('/(?<=\s)@breakswitch(?=\s)/', '<?php break;', $value);
    return $value;
  });

回答8:

When you start using switch statements within your views, that usually indicate that you can further re-factor your code. Business logic is not meant for views, I would rather suggest you to do the switch statement within your controller and then pass the switch statements outcome to the view.