How to do it right! (Part 0)

And another series is born.

How to do it RIGHT.

My writing skills are severely lacking, And so is my ability to explain things sometimes,  and i’ve not contributed much back into the developing community of recent.. So this has spawned my new idea..

The series will be aimed at explaining how to achieve things in WordPress in a up to date manner, Aimed more at Theme Functions.php and Plugins rather than a Theme perspective.

So, To those few who are currently subscribed, Please comment with any ideas of what you’d like to see me write about, I’ll be starting off with some rather basic postings, but aim to keep the technical level around mid-range, with more advanced topics covered as well.

It is likely that i’ll repeat what is said in a few other blogs, but i hope to write it in a more understandable, and future proof manner, without the ancient hold-overs which I’ve seen over the past year..

My other thought was writing a sample plugin, and using that as the basis for the entire series, or maybe thats a different series, To build a semi-complex system, from the ground up, to solve a problem, and looking at the steps needed to solve it.. Any suggestions for plugins? I have something in mind, specifically, solve those problems some people think “Just can be done with WordPress”.

You’re doing it wrong #2

 

Welcome to part #2, If you missed #1, go check it out.

As i mentioned in the last posting, This time wp125 is featured again, No, Please dont get me wrong, i’m not just targeting certain plugins here, It’s merely the plugins which I use, which i have to modify  and/or cleanup for whatever reason, I’ve chosen WP125 to be used for this project, so here i am cleaning up some code. Also featured in the 2nd part of this posting, is TDO Mini Forms.

Who has ever seen an error message like this one?

Notice: Undefined index: wp125action in G:\www\nrtt\wp\wp-content\plugins\wp125\adminmenus.php on line 9
Notice: Undefined index: wp125action in G:\www\nrtt\wp\wp-content\plugins\wp125\adminmenus.php on line 13
Notice: Undefined index: wp125action in G:\www\nrtt\wp\wp-content\plugins\wp125\adminmenus.php on line 22
Notice: Undefined index: wp125action in G:\www\nrtt\wp\wp-content\plugins\wp125\adminmenus.php on line 26

I’m willing to bet  a lot of people would’ve seen this one time or another, It comes down to a very very VERY lazy developer in my opinion, Simply because its best programming practice to never actually hit this case..

The code which is causing this:

function wp125_write_managemenu() {
…<snip>…
//Handle deactivations
if ($_GET[‘wp125action’] == “deactivate”) {

Doesnt look too harmful really, now does it? Thats because, By itself, Its not harmful at all other than an annoying message, The harmful part, is where similar code is used, and its merely assumed that certain array items exist, The issue arises that it can make bugs slip by unnoticed..

So, Whats the correct way? Simply check that the Array item exists before comparing it against something else.

The simplest method would be:

if ( isset($_GET['wp125action']) && ($_GET['wp125action'] == "deactivate") {

Or alternatively, If you never want to fire when the array item is empty:

 if ( !empty($_GET['wp125action']) && ($_GET['wp125action'] == "deactivate") {

Now, that wasnt too hard was it? Much cleaner, reduces warnings, and potentially reduces the risk of bugs.

Once again, All changes made are available as a Diff, This diff also includes the changes made in par #1, This has been written as of version 1.3.6.

Now, Onto the second plugin, TDO Mini Forms, This isnt actually a half bad plugin overall,  However, The code can be a bit messy for lack of a better word thanks to the many many many options and defines it uses.

Most of the issues i’ve got with this plugin, boils down to mis-use of constants, for example:

Notice Use of undefined constant TDOMF_OPTION_WIDGET_MAX_HEIGHT - assumed 'TDOMF_OPTION_WIDGET_MAX_HEIGHT' in G:\www\nrtt\wp\wp-content\plugins\tdo-mini-forms\admin\tdomf-options.php on line 604

Upon actually looking through he code, The Define was used in many places, but never actually defined. However, TDOMF_OPTION_WIDGET_MAX_WIDTH, and TDOMF_OPTION_WIDGET_MAX_LENGTH were, But guess what, The latter was never actually used, other than during option creation.. It’s a simple typo really.. But a quick fix never the less.

The main thing that has been bugging me with this plugin however, are these splattered around:

Notice: Use of undefined constant REQUEST_URI - assumed 'REQUEST_URI' in G:\www\nrtt\wp\wp-content\plugins\tdo-mini-forms\admin\tdomf-form-options.php on line 15

It looks like the plugin is expecting some form of register_globals for  the $_SERVER items to be enabled, Well, Do i have news for you… Its not! To many programmers that  may have sounded like the actual problem, But the problem is actually a coding flaw.. (as expected)

if(preg_match('/tdomf_show_form_menu/',$_SERVER[REQUEST_URI])) {

May not see something wrong with that, But, You should. $_SERVER contains an array element called ‘REQUEST_URI’, which is what the author intended to access, But instead, what they have asked for, Is the $_SERVER array element whose name is within the REQUEST_URI definition.. PHP is smart enough to convert that REQUEST_URI into a string, and so the code works as expected, for now.. But it’s still sloppy, Adding 2 apostrophe’s into the mix fixes everything.. Quick and simple really..

if(preg_match(‘/tdomf_show_form_menu/’,$_SERVER[‘REQUEST_URI’])) {

And the final piece of the puzzle for this posting:

Notice: Trying to get property of non-object in G:\www\nrtt\wp\wp-content\plugins\tdo-mini-forms\admin\tdomf-edit-post-panel.php on line 36

Another common type of warning produced by PHP, Very similar to the first Array item above:

function tdomf_edit_post_panel_admin_head() {
   global $post;
   // don't show on new post/page
   if($post->ID > 0) {

Now, This wouldnt be all that bad really.. If it wasnt for this code:

add_action( 'admin_head', 'tdomf_edit_post_panel_admin_head' );

The end result, much like I explained in Post #1, Is that running code designed for a SINGLE page on EVERY page load, is not a good thing to do, eventually you’ll hit a road bump like this one..

While the most appropriate fix for this, would be to simply only hook the function to run on the post edit page, Due to this plugins insisting to be backwards compatible at one stage or another utilising the latest hook names is not always possible, So merely adding an is_object() call in there can silence and fix everything quickly:

function tdomf_edit_post_panel_admin_head() {
 global $post;
 // don't show on new post/page
 if(is_object($post) && $post->ID > 0) {

I should however note, That this plugin includes compat code for WordPress < 2.5, Whilst, It utilises WordPress 2.8 functionalities now. Plugin Authors: Keep an eye on your obsolete code, it increases complexity, and will eventually end up causing a bug. My methodology is to only support the latest WordPress release.. It’s not worth your time developing for users not upgrading their version of WordPress. Yes, You’re going to have people complain the plugin isnt compatible, but in reality, you’re doing them a favour, If they dont upgrade WordPress, they’ll have other bugs.. Your plugin not working is the least of their worries (Or should be) .

Thats it for now, TDO Mini Forms also contains many MANY uses of undefined variables, eg:

Notice: Undefined variable: edit in G:\www\nrtt\wp\wp-content\plugins\tdo-mini-forms\include\tdomf-form.php on line 387

But the plugin is too large for me to want to go in and fix everything,  what has impacted me the most has been fixed, i’ll leave it as that.

Until next time, The changes made to TDO Mini Forms is available as a Diff, as of version 0.13.5. Apologies for the Diff here,I’m having issues with Line endings, Tortoise SVN isn’t respecting its own setting – You’ll have to patch a local copy and set it to ignore line ending changes..

 

EDIT: Fixed typo’s and lack of English. Sorry, I need a new computer, this T key hardly ever works when i want it to..

You’re doing it wrong #1

Welcome to a new series of mine, You’re doing it wrong. Now, You may’ve guessed what this series is going to be about.. WordPress “Programmers” doing things wrong.

Right now, I’m writing a new theme for a website, utilising a few plugins,  one of them is WP125.

 Notice: Trying to get property of non-object in G:\www\nrtt\wp\wp-includes\general-template.php on line 366

Yep, You’re doing it wrong. First glance it looks like its caused by WordPress, but after a lot of debugging, Here’s a stacktrace:

#0 G:\www\nrtt\wp\wp-includes\general-template.php(367) stackTrace(Array ( ) )
#1 G:\www\nrtt\wp\wp-includes\script-loader.php(410) get_bloginfo(Array ( [0] => text_direction ) )
#2 unknown(unknown) wp_default_styles(Array ( [0] => CONVERTED OBJECT OF CLASS WP_Styles ) )
#3 G:\www\nrtt\wp\wp-includes\plugin.php(414) call_user_func_array(Array ( [0] => wp_default_styles [1] => Array ( [0] => CONVERTED OBJECT OF CLASS WP_Styles ) ) )
#4 G:\www\nrtt\wp\wp-includes\class.wp-styles.php(31) do_action_ref_array(Array ( [0] => wp_default_styles [1] => Array ( [0] => CONVERTED OBJECT OF CLASS WP_Styles ) ) )
#5 G:\www\nrtt\wp\wp-includes\functions.wp-styles.php(72) CONVERTED OBJECT OF CLASS WP_Styles->__construct(Array ( ) )
#6 G:\www\nrtt\wp\wp-content\plugins\wp125\adminmenus.php(8) wp_enqueue_style(Array ( [0] => thickbox ) )
#7 G:\www\nrtt\wp\wp-content\plugins\wp125\wp125.php(75) require_once(Array ( [0] => G:\www\nrtt\wp\wp-content\plugins\wp125\adminmenus.php ) )
#8 G:\www\nrtt\wp\wp-settings.php(566) include_once(Array ( [0] => G:\www\nrtt\wp\wp-content\plugins\wp125\wp125.php ) )
#9 G:\www\nrtt\wp\wp-config.php(109) require_once(Array ( [0] => G:\www\nrtt\wp\wp-settings.php ) )
#10 G:\www\nrtt\wp\wp-load.php(30) require_once(Array ( [0] => G:\www\nrtt\wp\wp-config.php ) )
#11 G:\www\nrtt\wp\wp-admin\admin.php(20) require_once(Array ( [0] => G:\www\nrtt\wp\wp-load.php ) )
#12 G:\www\nrtt\wp\wp-admin\edit.php(10) require_once(Array ( [0] => G:\www\nrtt\wp\wp-admin\admin.php ) )

Do you notice whats happening here?  A seasoned WordPress developer should.. But many will not, As it’s a huge problem amongst some plugins..

The issue at hand here, Is that the WP125 plugin, is running code as soon as its included, In this case, its registering styles and scripts as soon as the plugin is included. NOT a good thing to do.

A plugin should NEVER run any code as soon as its included*, All code should be placed inside actions.

Eg, Instead of this:

if(is_admin()){
 wp_enqueue_script('jquery');
 wp_enqueue_script('thickbox');
 wp_enqueue_style('thickbox'); 
}

It should be:

add_action('admin_head', 'wp125_enqueue_styles');
function wp125_enqueue_styles() {
 wp_enqueue_script('jquery');
 wp_enqueue_script('thickbox');
 wp_enqueue_style('thickbox'); 
}

*1: Obviously, there are some cases where running code is considered ok, but it should be avoided. I’m ignoring calls to add_action/add_filter as running code here, as thats the way things should happen.

There  is one more thing which should be noted as well.. another thing a plugin should NEVER do, Is enqueue Scripts and Styles for EVERY administration page, Only load them on the pages which require the script. So lets take that last semi-better-than-original  sniplet and convert it to something which is how ALL plugins should be registering their scripts and styles:

So, Now I’m going to introduce you to one more function which many developers seem to miss, the action admin_print_scripts-<slug>

This action is actually pretty simple, On every pageload of WordPress Administration, many dynamic hooks are fired, in particular interest today, is the admin_print_scripts-<slug> hook. This fires when WordPress decides its time to start printing the <script> and <link rel=”stylesheet” /> items into the head of the document. This is where plugins should be hooking their addition of styles and scripts, As well as printing any extra <head> content to fit into the WordPress admin pages for their plugin.

Without going into it in depth, I’m just going to give a chunk of code, The only thing worth noting, is if you’re not sure of the slug of your page, Quite handy is, that the add_menu_*() functions will return it.. So, Finally, Here we go:

//Add the Admin Menus
add_action('admin_menu', 'wp125_add_admin_menu');
function wp125_add_admin_menu() {
 load_plugin_textdomain('wp125', PLUGINDIR.'/'.dirname(plugin_basename(__FILE__)).'/translations', dirname(plugin_basename(__FILE__)).'/translations');
 $pages = array();
 $pages[] = add_menu_page(__("125x125 Ads", 'wp125'), __("Ads", 'wp125'), MANAGEMENT_PERMISSION, __FILE__, "wp125_write_managemenu");
 $pages[] = add_submenu_page(__FILE__, __("Manage 125x125 Ads", 'wp125'), __("Manage", 'wp125'), MANAGEMENT_PERMISSION, __FILE__, "wp125_write_managemenu");
 $pages[] = add_submenu_page(__FILE__, __("Add/Edit 125x125 Ads", 'wp125'), __("Add/Edit", 'wp125'), MANAGEMENT_PERMISSION, 'wp125_addedit', "wp125_write_addeditmenu");
 $pages[] = add_submenu_page(__FILE__, __("125x125 Ad Settings", 'wp125'), __("Settings", 'wp125'), MANAGEMENT_PERMISSION, 'wp125_settings', "wp125_write_settingsmenu");

 foreach ( $pages as $my_page )
   add_action('admin_print_scripts-' . $my_page, 'wp125_register_scripts_styles', 9); //Add it a little earlier.

 //Include menus
 require_once(dirname(__FILE__).'/adminmenus.php');
}

function wp125_register_scripts_styles() {
 wp_enqueue_script('jquery');
 wp_enqueue_script('thickbox');
 wp_enqueue_style('thickbox');
}

The main benefit of behaving yourself? Much less chance of screwing up another admin page’s styling or JavaScript :)

Stay tuned for the next edition of this, Where once again, WP125 will feature, along side TDO Mini Forms

See Attachment for a .diff of the changes made to the plugin. NOTE: This is as of version 1.3.6

Photos from Byron/Brunswick Heads

A few (bad quality) Panorama’s made using a G10 and AutoStitch (Which has never failed me in the past, But really doesnt work well with these photos..)

More single-shots to come.. The light conditions weren’t the best for someone not sure of what they’re doing either ;)