Basic File Caching

Overview

Objective

Learn the basics of caching data in ProdigyView to help speed up your server’s performance.

Requirements

Basic Understanding of Cache

Estimated Time

12 Minutes

Follow Along With Code Example

1. Download a copy of the example code at www.prodigyview.com/source.

2. Install the system in an environment you feel comfortable testing in.

3.Proceed to examples/system/Cache.php

Create Cache

Writing a file to cache is relatively simple. All you need is a key/name and content to put in the cache.

1. Initialize the cache object

2. Set the key/name 3. Write content to cache

Adding Options

Cache uses the default values that can be set in PVCache::init(). To override those default values, we can pass in our own options.

Modify Cache Expiration and the name of the cache

Set the expiration time in seconds

Reading The Cache

With cache that is stored, we need a way of reading it. They key/name used to save the cache will also be used for reading it.

The Cache TagBy default, the tag used to identify the cache is removed, If you want to read the cache tag, pass the options in not to remove the tag.

Set the option keeping the cache tag

Remember to set the cache name if not using the default

Cache Tag Results

Cache Tag

Cache Tag With Explicitly Set Name

Checking ExpirationOh, so that is the tag used for setting the expiration. Wait, how do you check the expiration? Simply pass the key/name of the file to check.

Check if the cache has expired by the key

Check name and key

Expiration DateIf you need to pull the expiration date from the file, PVCache::getExpiration() method will pull the date for you in a string format.

Get the expiration in a date format

Add the option to use a name for the cache

Expiration Date Result

Expiration date/time format

Delete CacheThe final step to manipulating the cache is to delete the cache. After it is deleted, accessing cache through that key will return a null.

Objects And Array

One of the coolest features about the cache in ProdigyView is the ability to store objects and arrays into cache. These data structures will be serialized on entry and unserialized on retrieval.

Set the cache key/name Pass array into cache

Read the cache as normal and print out key

How to use cacheWe know how to read, write, check and delete cache, but we actually use it? Simple, check then read or write.

1. Check if the cache has expired first 2. If is not expired, return the cache

3. If it has expired, query that database to find your content.

4. Write the content to cache and return it

Challenge!

This is an optional challenge to improve you understanding of cache.

1. Create a page with header , body and footer content in a string.

2. Write the header content to cache and set to expire in 3 minutes.

3. Write the body content to cache and set to expire in 5 minutes.

4. Write the footer content to cache and set to expire in 7 minutes.

5. Add new content to each section of the page only after the content has expired.

API ReferenceFor a better understanding of cache in ProdigyView, visit the api by clicking on the link below.

PVCache

www.prodigyview.com

More Tutorials

For more tutorials, please visit:

http://www.prodigyview.com/tutorials