Helper Functions

Nette\Utils\Helpers is a static class containing useful helper functions.

Installation:

composer require nette/utils

All examples assume the following class alias is defined:

use Nette\Utils\Helpers;

capture (callable $cb): string

Executes a callback and returns the captured output as a string.

$res = Helpers::capture(function () use ($template) {
	$template->render();
});

clamp (int|float $value, int|float $min, int|float $max): int|float

Clamps a value within the inclusive range specified by min and max.

Helpers::clamp($level, 0, 255);

compare (mixed $left, string $operator, mixed $right): bool

Compares two values the same way PHP does. It supports the operators >, >=, <, <=, =, ==, ===, !=, !==, <>. The function is useful in situations where the operator is determined dynamically (is a variable).

Helpers::compare(10, '<', 20); // true

falseToNull (mixed $value): mixed

Converts false to null; other values remain unchanged.

Helpers::falseToNull(false); // null
Helpers::falseToNull(123);   // 123

getLastError(): string

Returns the last occurred PHP error or an empty string if no error occurred. Unlike error_get_last(), it's not affected by the PHP directive html_errors and always returns text, not HTML.

Helpers::getLastError();

getSuggestion (string[] $possibilities, string $value): ?string

From the given $possibilities, it finds the string most similar to $value, but not identical. It only supports 8-bit encodings.

This is useful when a certain option is invalid, and you want to suggest a similar alternative to the user (but a different one, hence why identical strings are ignored). This is how Nette generates the “did you mean …?” messages.

$items = ['foo', 'bar', 'baz'];
Helpers::getSuggestion($items, 'fo');   // 'foo'
Helpers::getSuggestion($items, 'barr'); // 'bar'
Helpers::getSuggestion($items, 'baz');  // 'bar', not 'baz'