w3capi

A PHP wrapper/client for the W3C validator API

Quick disclaimer

I'm unsure how stable the actual W3C API is, as it's documented as experimental and subject to change; don't be surprised if things stop working. You can read more at http://validator.w3.org/docs/api.html

Pay special attention to this notice:

If you wish to call the validator programmatically for a batch of documents, please make sure that your script will sleep for at least 1 second between requests. The Markup Validation service is a free, public service for all, your respect is appreciated. thanks.

When making multiple calls through a validator instance, this will be done for you (see below).

Requirements:

PHP 5.3+
* cURL
* SimpleXML

* Can be abstracted away by providing alternative interfaces

Installation

This package can be installed manually or via Composer.

Composer

Add the following to your project's composer.json:

"repositories": [
    {
        "type": "vcs",
        "url":  "https://github.com/tcopestake/w3capi"
    }
],

and:

"require": {
    "tcopestake/w3capi": "*"
},

Manual

Download and extract the files.

If your project doesn't already have a suitable autoloader, you can use the one provided by including src/bootstrap.php:

include('path/to/src/bootstrap.php');

Usage

The validator

To validate a document:

$validator = new \W3CAPI\Validator;

try {
    $validator->validate('http://url.test.com/a-html-page');
} catch(\W3CAPI\Exceptions\SoapClientBadResponse $e) {
    echo "Most likely, W3C reported a server error.";
} catch(\W3CAPI\ValidatorUnknownError $e) {
    echo "Something went wrong, but we don't know what.";
}

If successful, information can then be retrieved from the instance, such as whether the document passed validation:

echo ($validator->isValid()) ? 'Valid' : 'Invalid';

and information about semantic validation errors:

if($validator->getErrorCount() > 0) {
    foreach($validator->getErrors() as $error) {
        /*
         * $error will be an array
         * containing the error message, etc.
         *
         */
    }
}

and information about validation warnings:

if($validator->getWarningCount() > 0) {
    foreach($validator->getWarnings() as $warning) {
        /*
         * $warning will be an array
         * containing the warning message, etc.
         *
         */
    }
}

If you wish to validate another document, the validator instance can be easily reused:

try {
    $validator->validate('http://another.url.com/shame.css');
} catch(\W3CAPI\Exceptions\SoapClientBadResponse $e) {
    echo "Most likely, W3C reported a server error.";
} catch(\W3CAPI\ValidatorUnknownError $e) {
    echo "Something went wrong, but we don't know what.";
}

Note that when making subsequent calls, the validator class will enforce W3C's "1 second" rule by delaying sending the request if necessary.

Tests

There are unit tests.

Possible developments(?)

Support for validating documents via POST upload.
More documentation (esp. on dependency injection).
Revisit the XML parser.
More transparency between classes e.g. ability to retrieve HTTP headers
Peer pressure is forcing me to switch to PSR-2, but my muscle memory forgets this sometimes.