Laravel 5 Translation Using the Double Underscore (__) Helper Function

The __ helper function can be used to retrieve lines of text from language files. You can retrieve lines of text from either key-based translation files (represented as PHP arrays) or from literal, string-based translation files (represented as a JSON object).

Replacements are passed as a key/value pair. The replacement keys will be matched to any placeholders within the translation string. Placeholders begin with a single colon (:) followed by a name and a space. For example, in the validation.php language file, the following lines can be found:

 1<?php
 2 
 3return [
 4 
 5    // ...
 6 
 7    'accepted'             => 'The :attribute must be accepted.',
 8    'active_url'           => 'The :attribute is not a valid URL.',
 9 
10    // ...
11 
12];

In the above translation lines, :attribute is a placeholder that can be replaced using the $parameters parameter. The following code examples will demonstrate the results of the $parameters parameter.

#Signature

The signature of the __ method is:

1function __(
2    $key,
3    $replace = [],
4    $locale = null
5);

#Example Use

If we look in the resources/lang/en/validation.php resource file, we will see something similar to the following defined at the top of the file:

1<?php
2 
3return [
4    // ...
5    'accepted'             => 'The :attribute must be accepted.',
6    // ...
7];

We can retrieve the accepted line like so:

1$translatedText = __('validation.accepted');

If the above code was executed, the $translatedText variable would contain the following value:

1The :attribute must be accepted.

However, the returned text contains the :attribute placeholder, we can supply arguments to the __ function using the $replace array parameter:

1$translatedText = __('validation.accepted', [
2        'attribute' => 'Terms of Service'
3    ]);

Now, with the newly supplied $replace argument, the $translatedText variable would now contain the following value:

1The Terms of Service must be accepted.

#Supplying a Locale

For the next example, we will create a new file at resources/lang/es.json to both showcase literal based language files as well as how the $locale parameter can be used.

The contents of this new validation.json file should be:

1{
2  "validation.accepted": "Los :attribute deben ser aceptados."
3}

We can resolve the Spanish translation for the accepted validation message like so:

1$translatedText = __('validation.accepted', [
2        'attribute' => 'términos de servicio'
3    ], 'es');

After the above example has executed, the $translatedText variable would contain the following value:

1Los términos de servicio deben ser aceptados.

#Example Within Blade Templates

The following examples demonstrate how we can retrieve language translations from within Blade templates:

1{{-- Using the __ helper function --}}
2    <p>
3        {{ __('validation.accepted',
4            ['attribute' => 'Terms of Service'])
5        }}
6    </p>
7 
8{{-- Using the @lang directive --}}
9@lang('validation.accepted', ['attribute' => 'Terms of Service'])

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