CaptureCache

The CaptureCache pattern is useful for generating static resources to return via HTTP request. When used in such a fashion, the web server needs to be configured to run a PHP script generating the requested resource so that subsequent requests for the same resource can be shipped without calling PHP again.

This pattern comes with basic logic for managing generated resources.

Quick Start

For use with an Apache 404 handler extend the Apache configuration, e.g. .htdocs:

ErrorDocument 404 /index.php

And add the cache to the related application script, e.g. index.php:

use Laminas\Cache\Pattern\CaptureCache;
use Laminas\Cache\Pattern\PatternOptions;

$capture = new CaptureCache(
    new PatternOptions([
        'public_dir' => __DIR__,
    ])
);

// Start capturing all output, excluding headers, and write to the public
// directory:
$capture->start();

// Don't forget to change the HTTP response code
header('Status: 200', true, 200);

// do stuff to dynamically generate output

Configuration Options

Examples

Scaling Images in the Web Root

Using the following Apache 404 configuration:

# .htdocs
ErrorDocument 404 /index.php

Use the following script:

// index.php
use Laminas\Cache\Pattern\CaptureCache;
use Laminas\Cache\Pattern\PatternOptions;

$capture = new CaptureCache(
    new PatternOptions([
        'public_dir' => __DIR__,
    ])
);

Available Methods

In addition to the methods exposed in PatternInterface, this implementation exposes the following methods.

namespace Laminas\Cache\Pattern;

use Laminas\Cache\Exception;

class CaptureCache extends AbstractPattern
{
    /**
     * Start the cache.
     *
     * [@param](https://github.com/param)  string $pageId  Page identifier
     * [@return](https://github.com/return) void
     */
    public function start($pageId = null);

    /**
     * Write a page to the requested path.
     *
     * [@param](https://github.com/param) string      $content
     * [@param](https://github.com/param) null|string $pageId
     * [@throws](https://github.com/throws) Exception\LogicException
     */
    public function set($content, $pageId = null);

    /**
     * Retrieve a generated page from the cache.
     *
     * [@param](https://github.com/param)  null|string $pageId
     * [@return](https://github.com/return) string|null
     * [@throws](https://github.com/throws) Exception\LogicException
     * [@throws](https://github.com/throws) Exception\RuntimeException
     */
    public function get($pageId = null);

    /**
     * Check if a cache exists for the given page.
     *
     * [@param](https://github.com/param)  null|string $pageId
     * [@throws](https://github.com/throws) Exception\LogicException
     * [@return](https://github.com/return) bool
     */
    public function has($pageId = null);

    /**
     * Remove a page from the cache.
     *
     * [@param](https://github.com/param)  null|string $pageId
     * [@throws](https://github.com/throws) Exception\LogicException
     * [@throws](https://github.com/throws) Exception\RuntimeException
     * [@return](https://github.com/return) bool
     */
    public function remove($pageId = null);

    /**
     * Clear cached pages that match the specified glob pattern.
     *
     * [@param](https://github.com/param) string $pattern
     * [@throws](https://github.com/throws) Exception\LogicException
     */
    public function clearByGlob($pattern = '**');

    /**
     * Returns the generated file name.
     *
     * [@param](https://github.com/param) null|string $pageId
     * [@return](https://github.com/return) string
     */
    public function getFilename($pageId = null);
}