Laminas Validator

Laminas provides a suite of validator classes specifically designed to verify the properties of files on disk or files uploaded via HTTP. These validators can check for file size, extensions, MIME types, checksums (CRC32, MD5, SHA1), image dimensions, and more.

Available file-related validators include:

• Count: Validates the number of files.
• crc32, md5, sha1, hash: Validates file integrity using specific algorithms.
• ExcludeExtension, Extension: Validates file extensions.
• ExcludeMimeType, MimeType: Validates the MIME type of the file.
• Exists, NotExists: Checks for the existence (or non-existence) of a file.
• FilesSize, Size: Validates file size constraints.
• ImageSize, IsImage: Validates image-specific properties.
• IsCompressed: Checks if a file is compressed.
• Upload, UploadFile: Validates uploaded file structures.
• WordCount: Validates the word count within a file.

The Laminas\Validator\Conditional validator allows you to execute a set of validators only if a specific condition is met. This is useful for fields that are only required or must follow certain formats based on the values of other fields in the payload.

How it works

1. The validator accepts a rule (a callable) and a list of validators.
2. The rule is executed, receiving the $context array (the full data payload) as its argument.
3. If the rule returns false, the validator automatically passes (true), skipping the sub-validators.
4. If the rule returns true, the validator proceeds to run the specified validators against the value being validated.

Configuration Options

• rule: A callable with the signature function(array $context): bool. It must return true to trigger validation or false to skip it.
• validators: A list of validator specifications used to create a validator chain. The format follows the standard ValidatorChainFactory specifications.

$validator = new Conditional($chainFactory, [
    'rule' => static function (array $context): bool {
        return (bool) ($context['subscribe'] ?? null) === true;
    },
    'validators' => [
        ['name' => EmailAddress::class],
    ],
]);

You can restrict the validator to specific types of hostnames using the allow option and Laminas\Validator\Hostname constants. You can combine multiple types using bitwise OR (|).

Available Constants:

• ALLOW_DNS: Only DNS hostnames (e.g., domain.com).
• ALLOW_IP: Only IP addresses (e.g., 1.2.3.4).
• ALLOW_LOCAL: Only local network names (e.g., localhost).
• ALLOW_URI: RFC3986-compliant addresses (includes WINS, NetInfo, and local hostnames in hosts files).
• ALLOW_ALL: All of the above types.

Example: Allow only IP addresses

use Laminas\Validator\Hostname;
$validator = new Hostname(['allow' => Hostname::ALLOW_IP]);

Example: Allow both DNS and Local hostnames

use Laminas\Validator\Hostname;
$validator = new Hostname([
    'allow' => Hostname::ALLOW_DNS | Hostname::ALLOW_LOCAL,
]);

use Laminas\Validator\Hostname;

// To check for IP addresses only
$validator = new Hostname(['allow' => Hostname::ALLOW_IP]);

// To accept DNS and Local hostnames
$validator = new Hostname([
    'allow' => Hostname::ALLOW_DNS | Hostname::ALLOW_LOCAL,
]);

When writing isValid(), you can choose between two logic patterns depending on how you want to report errors:

Dependent Conditions (Sequential)

Use this pattern if you want to stop validation as soon as the first error is encountered. This is useful when subsequent checks depend on the previous ones passing (e.g., checking if a value is numeric before checking if it is within a range).

Pattern:

if (! condition1) {
    $this->error(ERR_1);
    return false;
}
if (! condition2) {
    $this->error(ERR_2);
    return false;
}
return true;

Independent Conditions (Cumulative)

Use this pattern if you want to report all reasons why a value failed validation. This is useful for complex requirements like password strength, where a user should see all missing criteria at once.

Pattern:

$isValid = true;
if (! condition1) {
    $this->error(ERR_1);
    $isValid = false;
}
if (! condition2) {
    $this->error(ERR_2);
    $isValid = false;
}
return $isValid;