silverstripe-testsession/code/TestSessionStubCodeWriter.php

<?php
/**
 * Writes PHP to a file which can be included in SilverStripe runs on existence.
 * The generated file is included in page execution through {@link TestSessionRequestFilter}.
 */
class TestSessionStubCodeWriter
{

    /**
     * @var boolean Add debug statements to the generated PHP about
     * the generator's origin code location.
     */
    protected $debug = false;

    /**
     * @var String Absolute path to a PHP file, essentially the "name" of the stub.
     */
    protected $filePath;

    public function __construct($filePath = null)
    {
        $this->filePath = $filePath ? $filePath : BASE_PATH . '/testSessionStubCode.php';
    }

    /**
     * Writes arbitrary PHP code to {@link $filePath} for later inclusion.
     * Creates the file if it doesn't exist.
     * Adds debug information about the origin of this code if {@link $debug} is set.
     * 
     * @param String $php Block of PHP code (without preceding <?php)
     * @param boolean $eval Sanity check on code.
     */
    public function write($php, $eval = true)
    {
        $trace = $this->debug ? debug_backtrace() : null;
        $path = $this->getFilePath();
        $header = '';

        // Create file incl. header if it doesn't exist
        if (!file_exists($this->getFilePath())) {
            touch($this->getFilePath());
            if ($this->debug) {
                $header .= "<?php\n// Generated by " . $trace[1]['class'] . " on " . date('Y-m-d H:i:s') . "\n\n";
            } else {
                $header .= "<?php\n";
            }
        }

        // Add content
        if ($this->debug) {
            $header .= "// Added by " . $trace[1]['class'] . '::' . $trace[1]['function'] . "\n";
        }
        file_put_contents($path, $header . $php . "\n", FILE_APPEND);
    }

    public function reset()
    {
        if (file_exists($this->getFilePath())) {
            unlink($this->getFilePath());
        }
    }

    public function getFilePath()
    {
        return $this->filePath;
    }

    public function getDebug()
    {
        return $this->debug;
    }

    public function setDebug($debug)
    {
        $this->debug = $debug;

        return $this;
    }
}