Userdata functions

Latest revision as of 10:09, 24 August 2007

Introduction

The idea behind the userdata class is to make it easy for plugin developers to store and retrieve basic user-inputted information for use with their plugin --- account ids, display preferences, etc. --- without having to create a whole db table for it.

When to use it

If you're developing a plugin and find yourself about to create a whole db table just to store one row's worth of misc information related to your plugin (i.e. preference settings, color values, etc.), stop, follow the vague memory of this sentence back to this page, and check out this userdata method.

When NOT to use it

If your plugin needs to insert multiple records or rows of something --- like coupon codes, guestbook entries, etc. --- you probably still want to create a dedicated table for that. The userdata functions are not meant for that.

Why it's useful

• Fewer lines of code
• Fewer keystrokes per line (no mysql query strings to write)
• No worrying about creating a separate db in the install manifest.
• Plugin userdata automatically uninstalled by product, no need to account for it in install manifest

How to use it

new

The basic idea here is to stick this line at the top of any script that uses the get() and set() functions. Replace "myplugin" with the name of your plugin folder. The other methods depend on this being set. If you don't do this first and try to call get() or set() php will bomb a fatal error.

$myplugin = new userdata("myplugin");

set()

Updates value of specific field (or inserts as new rec if fieldname not found)

$myplugin->set("firstname", "mike");

get()

Syntax

$myplugin->get([fieldname])

If $fieldname is NOT passed - Gets all userdata related to passed plugin and returns it in an array

If $fieldname IS passed - Gets data for requested field and returns it

Example #1: Get data from specific field.

echo $myplugin->get("firstname");

Example #2: Get all userdata stored for your plugin in an associative array (indexed by fieldname). Think of this as doing a mysql_fetch_array() on that one-row table you were going to create before discovering this userdata stuff.

$myprefsArray = $myplugin->get();

Bringing it all together

In this example, each available function is used.

$myplugin = new userdata("myplugin");

$myplugin->set("firstname", "John");
$myplugin->set("lastname", "Smith");

// This outputs "John Smith"
echo $myplugin->get("firstname")." ".$myplugin->get("lastname");

// This also outputs "John Smith"
$myData = get();
echo $myData['firstname']." ".$myData['lastname'];

Setting default values

Let's say you're using the userdata functions to store color values that you then retrieve in a template include to colorize certain template elements accordingly. Without setting any default values, the template will likely have a bunch of un-colored parts that should have colors (think transparent backgrounds where a solid bg color is expected) --- which may look a bit screwy --- until the user goes in to your config form and actually sets some values for those colors. This is where defaults come in handy. Here's how you can do them...

Example #1 - Setting a default background color of "#cccccc" (light gray) for an html element that you're outputting with a php template include.

<?
# Gotta do this first before you try to store/retrieve any of your data
# You can think of it like setting the "mode" to "working data related to your plugin specifically"
$mycolors = new userdata('myplugin');

# If no value exists, set the default
if ( $mycolors->get("headerbg") == "" ) {
   $mycolors->set("headerbg", "cccccc");
}
?>

<div id="header" style="background-color: #<? echo $mycolors->get("headerbg"); ?>;">
 This is my header
</div>