Classes e Funções usadas: actions, add_action, add_filter, filters, hooks, the_content

Categoria: Codex | Nenhum comentário

Um importante recurso a ser explorado para o desenvolvimento de soluções no WordPress é a utilização dosHooks que o sistema disponibiliza. Os Hooks são certas funções e identificadores que servem como ganchos (dada sua nomenclatura) para execução de instruções personalizadas. Significa dizer que através do uso dos hooks é possível informar ao sistema quando e como ele deve chamar determinada função.

Existem dois tipos de ganchos oferecidos pelo WordPress: Actions e Filters. As Actions, são ações executadas em determinados momentos pelo sistema; são atividades executadas mediante o disparar de um evento, como por exemplo o publicar de um post.

Os Filters, são os filtros da informação; através de suas aplicações o desenvolvedor consegue modificar ou como o próprio nome diz, filtrar os dados enviados pelo usuário ou resgatados do banco de dados antes que estes sejam exibidos ou armazenados.

Motivos para utilização dos Hooks

Em alguns casos quando se faz necessário alterar o modo de funcionamento do WordPress, é comum desenvolvedores realizarem tais alterações diretamente no código-fonte do CMS. No entanto essa prática é pouco recomendada, pois assim que o sistema for atualizado é bem provável que as alterações se percam e tenham que ser realizadas novamente. Usar os ganchos do WordPress é um jeito seguro de alterar o comportamento e as atividades executadas pela ferramenta.

A própria programação do sistema é realizada em grande parte com base nos Hooks. Veja por exemplo a utilização das Include Tags que se baseiam nesse princípio, assim como a incorporação de scripts ao WordPress que ocorre em razão do uso de ganchos.

Actions – Eventos do WordPress

Para adicionar ações ao WordPress é preciso fazer uso da função add_action via programação PHP com os seguintes parâmetros:

add_action ( 'nome_do_gancho', 'sua_funcao', [prioridade], [argumentos_aceitos] );

• Nome do gancho – Um evento fornecido pelo sistema (veja a Referência de ações no Codex), a ele será incorporada sua função;
• Sua função – Ao disparar do referido evento, a função aqui atribuída será executada;
• Prioridade – Determina a ordem de execução das funções associadas ao gancho, por padrão seu valor é 10. Números menores são executados primeiro, e em caso de valores iguais respeita-se a ordem de adição das funções;
• Argumentos aceitos – Número inteiro que determina a quantidade de argumentos a serem passados para a função, possui valor 1 como padrão.

Estilo personalizado para a tela de login

Em um exemplo de aplicação, é possível editar a tela de login do seu template incorporando uma folha de estilo específica na página de entrada do sistema mediante o uso de:

function add_login_style() {
	wp_enqueue_style( 'login' );
}
add_action( 'login_head', 'add_login_style' );

Os parâmetros Prioridade e Argumentos aceitos são opcionais, caso não os informe, os valores padrões serão adotados para a ação criada.

Filters – Filtrando informação

De maneira semelhante a incorporação de ações ao sistema, para se incluir um filtro a ele é preciso fazer uso da função add_filter e seus respectivos parâmetros:

add_filter ( 'nome_do_gancho', 'sua_funcao', [prioridade], [argumentos_aceitos] );

Uma grande diferença na função a ser utilizada é que ela deverá possuir um valor de retorno ou de impressão usando os recursos return ou echo do PHP, por exemplo. Assim como para as Actions, os valores Prioridade eArgumentos aceitos da função que adiciona os Filters, são opcionais.

Alterando a exibição do conteúdo

Para demonstrar a utilização dos filtros, o exemplo abaixo irá suprimir todas as tags HTML do conteúdo dos posts resgatados antes de exibí-los para o visitante:

function content_only_text( $content ) {
	return strip_tags( $content );
}
add_filter( 'the_content', 'content_only_text' );

Fonte: http://www.guiawp.com.br/codex/hooks-actions-filters/

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Michael Fields

Hi Betsy, I hope this explains everything!

So, are filters a subset of actions?

They are basically the same function applied to different contexts. If you take a peek into the core, you will see that add_action is actually a wrapper function for add_filter:

function add_action($tag, $function_to_add, $priority = 10, $accepted_args = 1) { return add_filter($tag, $function_to_add, $priority, $accepted_args); }

it seems I could use an action to change the text of the post for instance, instead of a filter?

Actually, you would use a filter for this situation. Let’s pretend that WordPress is a Mexican restaurant and we have ordered a taco as illustrated by the following code…

<?php $taco = 'chicken'; ?>

Basically, we have no choice… we will always be served a chicken taco. However, the same expression could be stated using the apply_filters() function. It is like ordering a taco and having the server ask you “well what kind of taco would you like?”

<?php $taco = apply_filters( 'get_taco', 'chicken' ); ?>

The above code gives us access to the type of taco that we would like to have served. We can create a function which hooks into WordPress an changes the default value of$taco.

<?php add_filter( 'get_taco', 'my_special_order' ); function my_special_order( $content ) { return 'shredded beef'; } ?>

By adding the above code to you theme’s functions.php file or to a custom plugin, you are able to change the value of the variable $taco to whatever you like. Notice that the function “my_special_order” accepts one value. In this situation the value of$content is equal to the value of the second argument passed to the apply_filters() function. In this example it would be “chicken”.

<?php add_filter( 'get_taco', 'my_special_order' ); function my_special_order( $content ) { return $content . ' and avocado'; } ?>

The above code appends a string to the end of “chicken” resulting in a value of “chicken and avocado”.

what would be a good example of correctly using filters while actions would be inappropriate for the situation?

Basically, there usually is no choice for a plugin or theme developer as to which method they can use. The WordPress core is filled with calls to apply_filters() anddo_action(). If I need to change the value of a piece of data, I will search through the core until I locate the file where that data is defined and see if it is possible to filter it’s value.

If I need to do something at a certain time, I will look for calls to the do_action() hook. A simple example would be if I wanted to print custom css to the head of the document. I could easily add the following code to my theme’s functions.php file:

<?php add_action( 'wp_head', 'print_my_custom_scripts' ); function print_my_custom_scripts(){ print '<style type="text/css">.red{color:#f00;}</style>'; } ?>

Notice how this time, the function did not return a value – it did something -> it printed text to the browser.

Filters change data while actions allow us to do stuff.

when should I use an action and when a filter?

You would want to use an action where you need to do something at a certain point in time… add options to the database or print css or javascript.

You should use a filter where you would want to alter the value of some data that WordPress has passed through the apply_filters() function.

do the ‘hooks’ for actions and filters overlap? -can I add a either a filter or an action to the same hook?

Actually, both filters and actions are hooks. That being said, the answer is “no”.

http://wordpress.org/support/topic/fliters-vs-actions-from-a-newbe

Publicado em 20 de abril de 2009. Autor do artigo: Denis F. Moreia

// disable default dashboard widgets
function disable_default_dashboard_widgets() {

remove_meta_box(‘dashboard_right_now’, ‘dashboard’, ‘core’);
remove_meta_box(‘dashboard_recent_comments’, ‘dashboard’, ‘core’);
remove_meta_box(‘dashboard_incoming_links’, ‘dashboard’, ‘core’);
remove_meta_box(‘dashboard_plugins’, ‘dashboard’, ‘core’);

remove_meta_box(‘dashboard_quick_press’, ‘dashboard’, ‘core’);
remove_meta_box(‘dashboard_recent_drafts’, ‘dashboard’, ‘core’);
remove_meta_box(‘dashboard_primary’, ‘dashboard’, ‘core’);
remove_meta_box(‘dashboard_secondary’, ‘dashboard’, ‘core’);

}

add_action(‘admin_menu’, ‘disable_default_dashboard_widgets’);

Do jeito que está acima, a ação ocorrerá para TODOS os usuários. Se quiser
customizar para um grupo de usuários específico ou para um usuário em
específico, use a função abaixo como base…. Sendo que “manage_options” é
uma função administrativa… Depois estude mais sobre as funções (Roles &
Capabilities)

if (!current_user_can(‘manage_options’)) {
add_action(‘wp_dashboard_setup’,
‘disable_default_dashboard_widgets’);

}

outro exemplo:

Efetuarei a customização apenas pros usuários “Editores”:

if (current_user_can(‘editor’)) {        add_action(‘wp_dashboard_setup’,
‘disable_default_dashboard_widgets’);

}

Exemplos acima retirados do seguinte link:
http://digwp.com/2010/10/customize-wordpress-dashboard/

Outro link interessante:

http://www.catswhocode.com/blog/10-wordpress-dashboard-hacks

No link acima, há como remover alguns menus do painel.

Fonte: Drika(Lista WordPress Brasil)

Neste caso vamos adicionar um box com alguns radios abaixo da caixa do editor de texto do wordpress.

PARTE 1

Supondo que colocamos o código num arquivo “/lib/destaques.php” será preciso dar carga no mesmo, incluindo uma linha no arquivo “functions.php” do seu tema. A linha será

“require_once(STYLESHEETPATH.’/lib/destaques.php’);”

O código abaixo cuida do box.

add_action(‘admin_menu’, ‘rpbr_add_inpost_box_destaque’);

function rpbr_add_inpost_box_destaque() {
add_meta_box(‘rpbr_inpost_box_destaque_page‘, ‘Destaque da página inicial‘, ‘rpbr_inpost_box_destaque‘, ‘page‘, ‘normal’, ‘high’);
add_meta_box(‘rpbr_inpost_box_destaque_post‘, ‘Destaque da página inicial‘, ‘rpbr_inpost_box_destaque‘, ‘post‘, ‘normal’, ‘high’);
}

O próximo código cuida da criação do conteúdo dos boxs, ou seja, cria os radios.

function rpbr_inpost_box_destaque() { ?>
<?php wp_nonce_field( plugin_basename(__FILE__), ‘rpbr_inpost_destaque_nonce’ ); ?>
<?php $_rpbr_destaque = rpbr_get_custom_field(‘_rpbr_destaque’); ?>
<br style=”clear: both;” />
<input type=”radio” name=“_rpbr_destaque” id=”rpbr_destaque” value=”ok_principal” <?php checked(‘ok_principal’, rpbr_get_custom_field(‘_rpbr_destaque’));?> />Destaque Principal &nbsp; &nbsp; &nbsp;
<input type=”radio” name=”_rpbr_destaque” id=”rpbr_destaque” value=”ok” <?php checked(‘ok’, rpbr_get_custom_field(‘_rpbr_destaque’));?> />Destaque Menor  &nbsp; &nbsp; &nbsp;
<input type=”radio” name=”_rpbr_destaque” id=”rpbr_destaque” value=”" <?php checked(”, rpbr_get_custom_field(‘_rpbr_destaque’));?> />Nenhum Destaque
<br style=”clear: both;” />
<?php
}

Para terminar, uma ação que salva o radio selecionado, sempre que a página/post for salvo.

add_action(‘save_post’, ‘rpbr_inpost_destaque_save‘, 1, 2);
function rpbr_inpost_destaque_save($post_id, $post) {

//    verify the nonce
if ( !isset($_POST['rpbr_inpost_destaque_nonce']) || !wp_verify_nonce( $_POST['rpbr_inpost_destaque_nonce'], plugin_basename(__FILE__) ) )
return $post->ID;

//    don’t try to save the data under autosave, ajax, or future post.
if ( defined(‘DOING_AUTOSAVE’) && DOING_AUTOSAVE ) return;
if ( defined(‘DOING_AJAX’) && DOING_AJAX ) return;
if ( defined(‘DOING_CRON’) && DOING_CRON ) return;

//    is the user allowed to edit the post or page?
if ( (‘page’ == $_POST['post_type'] && !current_user_can(‘edit_page’, $post->ID)) || !current_user_can(‘edit_post’, $post->ID ) )
return $post->ID;

$rpbr_destaque_value = $_POST['_rpbr_destaque'];

if ( $rpbr_destaque_value ) {
//    save/update
update_post_meta($post_id, ‘_rpbr_destaque‘, $rpbr_destaque_value);
} else {
//    delete if blank
delete_post_meta($post_id, ‘_rpbr_destaque‘);
}

}

FIM DA PRIMEIRA PARTE

PARTE 2

A parte 2 diz respeito a exibição das publicações marcadas como destaque.

O valor do radio selecionado é gravado como uma meta_key do post/page.

Desta forma é possível filtrar consultas.

O código abaixo pega a última publicação marcada como destaque principal:

$args = array(‘post_type’ => ‘any’,
‘showposts’ => 1,
‘orderby’=>’date’,
‘meta_key’=>’_rpbr_destaque‘,
‘meta_value’=>’ok_principal‘,
‘post_status’ => ‘publish’,
‘post__not_in’ => get_option( ‘sticky_posts’ ));
$recent = new WP_Query($args);

O código abaixo pega as últimas 6 publicações marcadas como destaque:

$args = array (
‘post_type’ => ‘any’,’
showposts’ => 6,
‘orderby’=>’date’,
‘meta_key’=>‘_rpbr_destaque’,
‘meta_value’=>’ok‘,
‘post_status’ => ‘publish’,
‘post__not_in’ => get_option( ‘sticky_posts’ ));
$recent = new WP_Query($args);

PASSO 3

No caso acima, o destaque principal pode aparecer no post associado a uma imagem. Neste caso, é interessante adicionar ao function.php do seu tema, o seguinte:

add_image_size( ‘destaque-principal’, 340, 230 );//destaque principal, home

Para finalizar, no corpo da página onde a chamada ao destaque principal será exibida, você coloca:

<div>
<?php if ( has_post_thumbnail() ) { ?> <a href=”<?php the_permalink(); ?>”><?php the_post_thumbnail( ‘destaque-principal’ ); ?></a> <?php } ?>
</div>

 

FUNÇÕES ÚTEIS

function rpbr_custom_field($field) {
echo rpbr_get_custom_field($field);
}
function rpbr_get_custom_field($field) {
global $post;

if ( null === $post ) return FALSE;

$custom_field = get_post_meta($post->ID, $field, true);

if ( $custom_field ) {
// sanitize and return the value of the custom field
return wp_kses_stripslashes( wp_kses_decode_entities( $custom_field ) );
}
else {
// return FALSE if custom field is empty
return FALSE;
}
}

By Jean-Baptiste Jung

Security has always been a hot topic. Offline, people buy wired homes, car alarms and gadgets to bring their security to the max. Online, security is important, too, especially for people who make a living from websites and blogs. In this article, we’ll show you some useful tweaks to protect your WordPress-powered blog.

1. Prevent Unnecessary Info From Being Displayed

The problem
When you fail to log into a WordPress blog, the CMS displays some info telling you what went wrong. This is good if you’ve forgotten your password, but it might also be good for people who want to hack your blog. So, why not prevent WordPress from displaying error messages on failed log-ins?

The solution
To remove log-in error messages, simply open your theme’s functions.php file, and paste the following code:

Save the file, and see for yourself: no more messages are displayed if you fail to log in.

Please note that there are several functions.php files. Be sure to change the one in your wp-content directory.

Code explanation
With this code, we’ve added a simple hook to overwrite the login_errors() function. Because the custom function that we created returns only null, the message displayed will be a blank string.

Source

• Tips for Securing WordPress²
• WordPress Security: Hide Log-In Error Messages³

2. Force SSL Usage

The problem
If you worry about your data being intercepted, then you could definitely use SSL. In case you don’t know what it is, SSL is a cryptographic protocol that secures communications over networks such as the Internet.

Did you know that forcing WordPress to use SSL is possible? Not all hosting services allow you to use SSL, but if you’re hosted on Wp WebHost⁴ or HostGator⁵, then SSL is enabled.

The solution
Once you’ve checked that your Web server can handle SSL, simply open your wp-config.php file (located at the root of your WordPress installation), and paste the following:

Save the file, and you’re done!

Code explanation
Nothing hard here. WordPress uses a lot of constants to configure the software. In this case, we have simply defined the FORCE_SSL_ADMIN constant and set its value to true. This results in WordPress using SSL.

Source

• How To: Force Using SSL on wp-admin Directory⁶

3. Use .htaccess To Protect The wp-config File

The problem
As a WordPress user, you probably know how important the wp-config.php file is. This file contains all of the information required to access your precious database: username, password, server name and so on. Protecting the wp-config.php file is critical, so how about exploiting the power of Apache to this end?

The solution
The .htaccess file is located at the root your WordPress installation. After creating a back-up of it (it’s such a critical file that we should always have a safe copy), open it up, and paste the following code:

Code explanation
.htaccess files are powerful and one of the best tools to prevent unwanted access to your files. In this code, we have simply created a rule that prevents any access to the wp-admin.php file, thus ensuring that no evil bots can access it.

Source

• 10 Easy Ways to Secure Your WordPress Blog⁷

4. Blacklist Undesired Users And Bots

The problem
This is as true online as it is in real life: someone who pesters you today will probably pester you again tomorrow. Have you noticed how many spam bots return to your blog 10 times a day to post their annoying comments? The solution to this problem is quite simple: forbid them access to your blog.

The solution
Paste the following code in your .htaccess file, located at the root of your WordPress installation. As I said, always back up the .htaccess file before editing it. Also, don’t forget to change 123.456.789 to the IP address you want to ban.

Code explanation
Apache is powerful and can easily be used to ban undesirable people and bots from your website. With this code, we’re telling Apache that everyone is allowed to visit our blog except the person with the IP address 123.456.789.

To ban more people, simply repeat line 4 of this code on a new line, using another IP address, as shown below:

Source

• Over 150 of the Worst Spammers, Scrapers and Crackers from 2007⁸

5. Protect Your WordPress Blog From Script Injections

The problem
Protecting dynamic websites is especially important. Most developers always protect their GET and POST requests, but sometimes this is not enough. We should also protect our blog against script injections and any attempt to modify the PHP GLOBALS and _REQUEST variables.

The solution
The following code blocks script injections and any attempts to modify the PHP GLOBALS and _REQUEST variables. Paste it in your .htaccess file (located in the root of your WordPress installation). Make sure to always back up the .htaccess file before modifying it.

Code explanation
Using the power of the .htaccess file, we can check requests. What we’ve done here is check whether the request contains a <script> and whether it has tried to modify the value of the PHP GLOBALS or _REQUEST variables. If any of these conditions are met, the request is blocked and a 403 error is returned to the client’s browser.

Sources

• Protéger Son Site Avec Un Fichier .htaccess⁹
• Protect Your WordPress Blog Using .htaccess¹⁰

6. Fight Back Against Content Scrapers

The problem
If your blog is the least bit known, people will no doubt try to use your content on their own websites without your consent. One of the biggest problems is hot-linking to your images, which saps your server’s bandwidth.

The solution
To protect your website against hot-linking and content scrapers, simply paste the following code in your .htaccess file. As always, don’t forget to back up when modifying the .htaccess file.

Once you’ve saved the file, only your website will be able to link to your images, or, to be more correct, no one would link to your images, because it would be way too complicated and time-consuming. Other websites will automatically display the nohotlink.jpg image. Note that you can also specify a non-existent image, so websites that try to hot-link to you would display a blank space.

Code explanation
With this code, the first thing we’ve done is check the referrer to see that it matches our blog’s URL and it is not empty. If it doesn’t, and the file has a JPG, GIF, BMP or PNG extension, then the nohotlink image is displayed instead.

Source

• How to Protect Your Blog from Content Thieves¹¹

7. Create A Plug-In To Protect Your Blog From Malicious URL Requests

The problem
Hackers and evil-doers often use malicious queries to find and attack a blog’s weak spots. WordPress has good default protection, but enhancing it is possible.

The solution
Paste the following code in a text file, and save it as blockbadqueries.php. Once you’ve done that, upload it to your wp-content/plugins directory and activate it as you would any other plug-in. Now your blog is protected against malicious queries.

Code explanation
What this code does is pretty simple. It checks for excessively long request strings (more than 255 characters) and for the presence of either the eval or base64 PHP functions in the URI. If one of these conditions is met, then the plug-in sends a 414 error to the client’s browser.

Source

• Protect WordPress Against Malicious URL Requests/¹²

8. Remove Your WordPress Version Number… Seriously!

The problem
As you may know, WordPress automatically displays the version you are using in the head of your blog files. This is pretty harmless if your blog is always up to date with the latest version (which is certainly what you should be doing anyway). But if for some reason your blog isn’t up to date, WordPress still displays it, and hackers will learn this vital piece of information.

The solution
Paste the following line of code in the functions.php file of your theme. Save it, refresh your blog, and voila: no more WordPress version number in the header.

Code explanation
To execute certain actions, WordPress uses a mechanism called “hooks,” which allow you to hook one function to another. The wp_generator function, which displays the WordPress version, is hooked. We can remove this hook and prevent it from executing by using the remove_action() function.

Source

• How to Remove the WordPress Version Number (the Right Way)¹³

9. Change The Default “Admin” Username

The problem
Brute force is one of the easiest ways to break a password. The method is simple: try as many different passwords as possible until the right one is found. Users of the brute force method use dictionaries, which give them a lot of password combinations.

But knowing your username certainly makes it easier for them to guess the right combination. This is why you should always change the default “admin” username to something harder to guess.

Note that WordPress 3.0 let you choose your desired username by default. Therefore, this tip is still usefull if you still use the old “admin” account from older WordPress versions.

The solution
If you haven’t changed the “admin” username yet, simply run the following SQL query to your database to change it for good. Don’t forget to specify your desired username.

Code explanation
Usernames are stored in the database. To change one, a simple UPDATE query is enough. Note that this query will not transfer posts written by “admin” to your new username; the source post below shows you how to easily do that.

Source

• 13 Useful WordPress SQL Queries You Wish You Knew Earlier/¹⁴

10. Prevent Directory Browsing

The problem
By default, most hosts allow directory listing. So, if you type www.yourblog.com/wp-includes in the browser’s address bar, you’ll see all of the files in that directory. This is definitely a security risk, because a hacker could see the last time that files were modified and access them.

The solution (Updated)
Just add the following to the Apache configuration or your .htaccess file:

Code explanation
Please note that it’s not enough to update the blog’s robots.txt file with Disallow: /wp*. This would prevent the wp-directory from being indexed, but will not prevent users from seeing it.

Source

• 18 WordPress Security Plug-ins and Tips to Secure Your Blog¹⁵

(al)

It is no secret that the standard search within WordPress is not very accurate. The problem is that WordPress takes your search term far too literally, meaning, that if you were to type “search+code+wordpress” in to our search box above, it would return every post that contains those terms (in this case over 30 posts), even though we have no such post with in our database. So, in actual fact even though there are over 30+ results, our reader will never actually find what they are looking for. We have to improve this.

In this post we have 10 really useful code snippets that will help improve your WordPress Search functionality.

How To Exclude Posts or Pages from Search Results

If you would like to be able to control which posts or pages should be excluded from WordPress search results, all you have to do is copy and paste the code below into your functions.php file.

In this snippet, posts with the IDs 0 and 1 will be excluded. Edit accordingly to suit your needs.

Source: wprecipes.com →

WordPress Drop-Down Category Search Form

A useful function you could give to your WordPress search would be to allow your readers to filter the search results by targeting a specific category. This can be achieved by using a simple drop-down containing all of the category titles.

All you have to do is replace the standard WordPress search form (found within the searchform.php) with the snippet below:

Source: www.melandri.net →

Dynamically Search Categories and Child Categories Only

This search form snippet could be useful within the category archive to allow your readers to search the child categories from any given parent category.

In this snippet, all child categories from category ID 1 will be searched. Edit accordingly to suit your needs.

Source: wpgarage.com →

Search a Specific Post Type

WordPress gives you the ability to search specific post types by using this small snippet.

All you have to do is copy and paste the code below into your functions.php file.

Source: ashbluewebdesign.com →

Display the Number of Search Results Returned

If you would like to show your readers how many results have been found per search term, you could use this helpful snippet.

Open search.php and locate the following:

And replace it with this code:

Source: problogdesign.com →

Highlight WordPress Search Terms with jQuery

To help make your search results that little bit clearer to your readers, you could use this snippet which will highlight the searched term within the results.

Copy and paste the following code into your theme’s functions.php file:

And then add this code into your header.php file, just before the /head tag:

Source: weblogtoolscollection.com →

Disable WordPress Search

If you are looking for a way to disable all of WordPress’ search functionality, you could use this small snippet.

All you have to do is copy and paste the code below into your functions.php file.

Source: wpengineer.com →

Make your WordPress Search Results Unlimited

Sometimes you may not want your search results to be limited by the confines of the standard WordPress Loop. This snippet allows your search to return unlimited results.

In search.php you can add the following code above the loop for this functionality.

First of all find this code within search.php:

And then add this code:

Source: wphacks.com →

Implement Google AJAX Search API

Implement Google AJAX Search API →
Demo →
Google provides an awesome method in which you can use their search for your own site: the Google AJAX Search API. In this advanced tutorial you will be shown how to implement this awesome API within your own website.
Google’s AJAX Search API requires that you sign up for an API key, you can get it here: Google AJAX Search API

Create an Ajax-based Auto-completing Search Field for WordPress

Create an Ajax-based Auto-completing Search Field for WordPress →
When someone starts to type with the search field they will be presented with a drop-down box offering suggestions. This tutorial will show you how to implement thsi on your own site.
Please note that even if this code is fully functional, this is an experimentation, and the SQL query isn’t really optimized.

How To Add Google Custom Search To WordPress

Google Custom Search Engine →
In this tutorial you will be shown how to integrate Google’s Custom Search Engine into your blog, making it easier for your readers to find content and allow you to make some money with Adsense.
How To Add Google Custom Search To WordPress →

No arquivo wp-admin/includes/dashboard.php

• Comenta a linha 367 (versão 3.0.1)
  //printf(_n(‘Theme <span>%1$s</span> with <span>%2$s Widget</span>’, ‘Theme <span>%1$s</span> with <span>%2$s Widgets</span>’, $num_widgets), $switch_themes, $num);}
  para não exibir o thema atual

• Na linha 378 (versão 3.0.1)
  Acrescenta um if para que usuários pouco privilegiados não vejam  a mensagem que o wordpress precisa ser atualizado
  if ( current_user_can( ‘switch_themes’) ) {
  update_right_now_message();
  }

===============================================================

http://wordpress.org/extend/plugins/hide-update-reminder/

Hide Update Reminder

Hides the Update Reminder in the Admin for all non Admin users.

This plugin allows you to hide the update WordPress reminder from all users that are not assumed Administrators (cannot upgrade plugins).

If you have multiple users then this means those who are not admins don’t need to see the message. Useful for CMS based sites, so the client doesn’t see the notice.

Para quem faz uso um pouco mais avançado do WordPress, especialmente quem trabalha desenvolvendo sites com a plataforma, é bem comum aparecerem situações um tanto complexas. Para estas questões, seguem 13 fantásticos comandos SQL para WordPress!

Uma maneira prática de executar comandos SQL é através do phpMyAdmin. Até a hospedagem mais básica dá acesso à ferramenta de banco de dados, então não há dificuldades nisso. Uma vez no sistema, você deve selecionar aba “SQL” e escrever/colar a instrução SQL que deseja executar.

1. Alterar siteurl e homeurl

WordPress armazena o caminho absoluto da URL do site (“siteurl”) e URL da home (“homeurl”) no banco de dados. Portanto, se você transferir o seu site WordPress do localhost para o servidor, por exemplo, o site não vai carregar! Isso ocorre porque o caminho absoluto ainda está apontando para o seu localhost. Você vai precisar executar um comando para resolver isso.

UPDATE wp_options
SET option_value = REPLACE(option_value, 'http://www.enderecoantigo.com', 'http://www.endereconovo.com')
WHERE option_name = 'home'
OR option_name = 'siteurl';

2. Alterar GUID

Depois de migrar seu blog a partir de, por exemplo, localhost, para o servidor ou de um outro domínio para um novo domínio, você terá que corrigir as URLs para o campo GUID na tabela wp_posts. Isto é crucial, porque GUID é usado para montar o slug de seu post do caminho absoluto do artigo correto.

UPDATE wp_posts
SET guid = REPLACE (guid, 'http://www.enderecoantigo.com', 'http://www.endereconovo.com');

3. Alterar URL no conteúdo

O WordPress utiliza caminhos absolutos no URL ao invés de um caminho relativo quando vai armazená-los no banco de dados. Dentro do conteúdo de cada registro de artigo, ele armazena todas as URLs antigas referenciando as fontes antigas. Portanto, você precisará alterar todas essas URLs com o endereço do novo domínio.

UPDATE wp_posts
SET post_content = REPLACE (post_content, 'http://www.enderecoantigo.com', 'http://www.endereconovo.com');

4. Alterar apenas o caminho das imagens

Caso seja preciso alterar o domínio das imagens inseridas nas páginas e artigos, esta solução vai ajudar você a fazer isso de forma simples.

UPDATE wp_posts
SET post_content = REPLACE (post_content, 'src="http://www.enderecoantigo.com', 'src="http://www.endereconovo.com');

Também é preciso atualizar o GUID para o tipo “attachment” com a seguinte instrução SQL:

UPDATE wp_posts
SET guid = REPLACE (guid, 'http://www.enderecoantigo.com', 'http://www.endereconovo.com') WHERE post_type = 'attachment';

5. Atualizar Post Meta

Atualizar Post Meta funciona quase da mesma maneira como atualizar a URL no conteúdo do post. Se você tiver dados extras para cada post, você pode usar a seguinte instrução para alterar todos eles.

UPDATE wp_postmeta
SET meta_value = REPLACE (meta_value, 'http://www.enderecoantigo.com','http://www.endereconovo.com');

6. Alterar o nome usuário padrão “admin”

Apesar de que na versão 3 do WordPress o usuário “admin” poderá ser alterado no momento da instalação, não custa deixar para a posteridade a dica de como alterar o nome do “admin”.

UPDATE wp_users
SET user_login = 'nomequevocequiser'
WHERE user_login = 'Admin';

7. Resetar password

Já quis resetar sua senha no WordPress mas, por algum motivo, não conseguiu usar a seção para resetar o password? Eis a solução:

UPDATE wp_users
SET user_pass = MD5('senha')
WHERE user_login = 'login';

8. Transferir artigos de um autor para outro

Para transferir os artigos de um autor para outro, você gasta um tempo enorme se fizer isso manualmente. Com o comando SQL a seguir, é possível fazer isso facilmente. Para a dica, é preciso saber o ID dos autores.

UPDATE wp_posts
SET post_author = 'id_novo_autor'
WHERE post_author = 'id_autor_antigo';

9. Apagar revisões

Quando se está editando um artigo no WordPress, é comum cópias de segurança serem feitas para garantir o trabalho feito. São as chamadas “revisões”. Com o tempo, o número de registros de revisões fica grande e isso pode comprometer a performance do banco de dados. Para apagar todas as revisões de artigos, dê o seguinte comando SQL:

DELETE a,b,c FROM wp_posts a
LEFT JOIN wp_term_relationships b ON (a.ID = b.object_id)
LEFT JOIN wp_postmeta c ON (a.ID = c.post_id)
WHERE a.post_type = 'revision'

10. Apagar post meta

Instalar e remover plugins é algo corriqueiro quando se trabalha com WordPress. Alguns plugins precisam de criar alguns post meta para funcionarem corretamente e, para esses casos, não é raro o acontecimento de, mesmo depois de o plugin ser desinstalado, algum “garbage meta” ficar enchendo o BD desnecessariamente. Uma limpeza em algum valor de post meta, às vezes, se faz necessária.

DELETE FROM wp_postmeta
WHERE meta_key = 'nome-chave-meta';

11. Exportar todos os e-mails de comentários

Quanto mais tempo seu blog/site fica no ar, é provável que mais comentários receba nos artigos publicados. Se, por algum motivo, for preciso uma listagem com e-mail de todas as pessoas que já comentaram até então, basta executar o seguinte comando:

SELECT DISTINCT comment_author_email
FROM wp_comments;

Uma vez que a listagem esteja concluída, exporte tudo através do phpMyAdmin.

12. Apagar todos pingbacks

A medida que o site/blog fica no ar – e se você tiver bom conteúdo a oferecer – o número de pingbacks começa a influenciar a qualidade do banco de dados. Para apagar todos pingbacks, proceda da seguinte maneira:

DELETE FROM wp_comments WHERE comment_type = 'pingback';

13. Apagar todos comentários de SPAM

Sem maiores explicações, eis a maneira de deletar todos os comentários marcados como SPAM:

DELETE FROM wp_comments
WHERE comment_approved = 'spam';

14. Identificar tags não usadas

Num banco de dados WordPress, se você executar alguma query SQL para apagar posts, as tags relacionadas não serão apagadas e continuarão aparecendo na nuvem de sugestão de tags e listagem de tags. Para identificar esse tipo de tag, execute a seguinte instrução SQL:

SELECT * FROM wp_terms wt
INNER JOIN wp_term_taxonomy wtt
ON wt.term_id=wtt.term_id
WHERE wtt.taxonomy='post_tag'
AND wtt.count=0;

Usando o notepad++ marcando a opção mostrada na imagem abaixo, o maldito warning sumiu.

Entenda melhor: http://kasolutions.wordpress.com/2009/07/14/fix-warning-session_start-function-session-start-cannot-send-session-cache-limiter-headers-already-sent/