Añadir paginación a WordPress sin ningún plugin.

Para poner en vuestro blog de Worpress un sistema de paginación como el de este Blog, tan solo tenemos que seguir 3 simples pasos:

1) functions.php

Este archivo se encuentra en la carpeta /wp-includes. Agregamos el siguiente código al final del archivo:

/***** Numbered Page Navigation (Pagination) Code.
      Tested up to WordPress version 3.1.2 *****/
 
/* Function that Rounds To The Nearest Value.
   Needed for the pagenavi() function */
function round_num($num, $to_nearest) {
   /*Round fractions down (http://php.net/manual/en/function.floor.php)*/
   return floor($num/$to_nearest)*$to_nearest;
}
 
/* Function that performs a Boxed Style Numbered Pagination (also called Page Navigation).
   Function is largely based on Version 2.4 of the WP-PageNavi plugin */
function pagenavi($before = '', $after = '') {
    global $wpdb, $wp_query;
    $pagenavi_options = array();
    $pagenavi_options['pages_text'] = ('Página %CURRENT_PAGE% de %TOTAL_PAGES%:');
    $pagenavi_options['current_text'] = '%PAGE_NUMBER%';
    $pagenavi_options['page_text'] = '%PAGE_NUMBER%';
    $pagenavi_options['first_text'] = ('Primera');
    $pagenavi_options['last_text'] = ('Última');
    $pagenavi_options['next_text'] = 'Siguiente &raquo;';
    $pagenavi_options['prev_text'] = '&laquo; Anterior';
    $pagenavi_options['dotright_text'] = '...';
    $pagenavi_options['dotleft_text'] = '...';
    $pagenavi_options['num_pages'] = 5; //continuous block of page numbers
    $pagenavi_options['always_show'] = 0;
    $pagenavi_options['num_larger_page_numbers'] = 0;
    $pagenavi_options['larger_page_numbers_multiple'] = 5;
 
    //If NOT a single Post is being displayed
    /*http://codex.wordpress.org/Function_Reference/is_single)*/
    if (!is_single()) {
        $request = $wp_query->request;
        //intval — Get the integer value of a variable
        /*http://php.net/manual/en/function.intval.php*/
        $posts_per_page = intval(get_query_var('posts_per_page'));
        //Retrieve variable in the WP_Query class.
        /*http://codex.wordpress.org/Function_Reference/get_query_var*/
        $paged = intval(get_query_var('paged'));
        $numposts = $wp_query->found_posts;
        $max_page = $wp_query->max_num_pages;
 
        //empty — Determine whether a variable is empty
        /*http://php.net/manual/en/function.empty.php*/
        if(empty($paged) || $paged == 0) {
            $paged = 1;
        }
 
        $pages_to_show = intval($pagenavi_options['num_pages']);
        $larger_page_to_show = intval($pagenavi_options['num_larger_page_numbers']);
        $larger_page_multiple = intval($pagenavi_options['larger_page_numbers_multiple']);
        $pages_to_show_minus_1 = $pages_to_show - 1;
        $half_page_start = floor($pages_to_show_minus_1/2);
        //ceil — Round fractions up (http://us2.php.net/manual/en/function.ceil.php)
        $half_page_end = ceil($pages_to_show_minus_1/2);
        $start_page = $paged - $half_page_start;
 
        if($start_page <= 0) {
            $start_page = 1;
        }
 
        $end_page = $paged + $half_page_end;
        if(($end_page - $start_page) != $pages_to_show_minus_1) {
            $end_page = $start_page + $pages_to_show_minus_1;
        }
        if($end_page > $max_page) {
            $start_page = $max_page - $pages_to_show_minus_1;
            $end_page = $max_page;
        }
        if($start_page <= 0) {
            $start_page = 1;
        }
 
        $larger_per_page = $larger_page_to_show*$larger_page_multiple;
        //round_num() custom function - Rounds To The Nearest Value.
        $larger_start_page_start = (round_num($start_page, 10) + $larger_page_multiple) - $larger_per_page;
        $larger_start_page_end = round_num($start_page, 10) + $larger_page_multiple;
        $larger_end_page_start = round_num($end_page, 10) + $larger_page_multiple;
        $larger_end_page_end = round_num($end_page, 10) + ($larger_per_page);
 
        if($larger_start_page_end - $larger_page_multiple == $start_page) {
            $larger_start_page_start = $larger_start_page_start - $larger_page_multiple;
            $larger_start_page_end = $larger_start_page_end - $larger_page_multiple;
        }
        if($larger_start_page_start <= 0) {
            $larger_start_page_start = $larger_page_multiple;
        }
        if($larger_start_page_end > $max_page) {
            $larger_start_page_end = $max_page;
        }
        if($larger_end_page_end > $max_page) {
            $larger_end_page_end = $max_page;
        }
        if($max_page > 1 || intval($pagenavi_options['always_show']) == 1) {
            /*http://php.net/manual/en/function.str-replace.php */
            /*number_format_i18n(): Converts integer number to format based on locale (wp-includes/functions.php*/
            $pages_text = str_replace("%CURRENT_PAGE%", number_format_i18n($paged), $pagenavi_options['pages_text']);
            $pages_text = str_replace("%TOTAL_PAGES%", number_format_i18n($max_page), $pages_text);
            echo $before.'<div class="pagenavi">'."\n";
 
            if(!empty($pages_text)) {
                echo '<span class="pages">'.$pages_text.'</span>';
            }
            //Displays a link to the previous post which exists in chronological order from the current post.
            /*http://codex.wordpress.org/Function_Reference/previous_post_link*/
            previous_posts_link($pagenavi_options['prev_text']);
 
            if ($start_page >= 2 && $pages_to_show < $max_page) {
                $first_page_text = str_replace("%TOTAL_PAGES%", number_format_i18n($max_page), $pagenavi_options['first_text']);
                //esc_url(): Encodes < > & " ' (less than, greater than, ampersand, double quote, single quote).
                /*http://codex.wordpress.org/Data_Validation*/
                //get_pagenum_link():(wp-includes/link-template.php)-Retrieve get links for page numbers.
                echo '<a href="'.esc_url(get_pagenum_link()).'" class="first" title="'.$first_page_text.'">1</a>';
                if(!empty($pagenavi_options['dotleft_text'])) {
                    echo '<span class="expand">'.$pagenavi_options['dotleft_text'].'</span>';
                }
            }
 
            if($larger_page_to_show > 0 && $larger_start_page_start > 0 && $larger_start_page_end <= $max_page) {
                for($i = $larger_start_page_start; $i < $larger_start_page_end; $i+=$larger_page_multiple) {
                    $page_text = str_replace("%PAGE_NUMBER%", number_format_i18n($i), $pagenavi_options['page_text']);
                    echo '<a href="'.esc_url(get_pagenum_link($i)).'" class="single_page" title="'.$page_text.'">'.$page_text.'</a>';
                }
            }
 
            for($i = $start_page; $i  <= $end_page; $i++) {
                if($i == $paged) {
                    $current_page_text = str_replace("%PAGE_NUMBER%", number_format_i18n($i), $pagenavi_options['current_text']);
                    echo '<span class="current">'.$current_page_text.'</span>';
                } else {
                    $page_text = str_replace("%PAGE_NUMBER%", number_format_i18n($i), $pagenavi_options['page_text']);
                    echo '<a href="'.esc_url(get_pagenum_link($i)).'" class="single_page" title="'.$page_text.'">'.$page_text.'</a>';
                }
            }
 
            if ($end_page < $max_page) {
                if(!empty($pagenavi_options['dotright_text'])) {
                    echo '<span class="expand">'.$pagenavi_options['dotright_text'].'</span>';
                }
                $last_page_text = str_replace("%TOTAL_PAGES%", number_format_i18n($max_page), $pagenavi_options['last_text']);
                echo '<a href="'.esc_url(get_pagenum_link($max_page)).'" class="last" title="'.$last_page_text.'">'.$max_page.'</a>';
            }
            next_posts_link($pagenavi_options['next_text'], $max_page);
 
            if($larger_page_to_show > 0 && $larger_end_page_start < $max_page) {
                for($i = $larger_end_page_start; $i <= $larger_end_page_end; $i+=$larger_page_multiple) {
                    $page_text = str_replace("%PAGE_NUMBER%", number_format_i18n($i), $pagenavi_options['page_text']);
                    echo '<a href="'.esc_url(get_pagenum_link($i)).'" class="single_page" title="'.$page_text.'">'.$page_text.'</a>';
                }
            }
            echo '</div>'.$after."\n";
        }
    }
}

2) Reemplazar la navegación

Ahora hay que editar los siguientes archivos del tema que estés usando ( wp-content/themes/nombre_del_tema ), los archivos son index.php, archive.php y search.php.

Debemos reemplazar la línea siguiente

<?php getpagenavi(); ?>

por ésta

<div class="navigation"><?php if(function_exists('pagenavi')) { pagenavi(); } ?></div>

3) Style.css

Y por último nos queda personalizar el Css de nuestro sistema de paginación, para ello debemos insertar en nuestro archivo Style.css (que se encuentra en el directorio de nuestro tema de WordPress) el siguiente código:

.pagenavi {
    margin: 0 0 20px 30px;
    padding: 5px 1px 5px;
    float:left;
    width: 98%;
}
.pagenavi a {
    padding: 5px 6px 4px 6px;
    margin: 3px;
    text-decoration: none;
    border: 1px solid #ccc;
    color: #666;
    background-color: inherit;
}
.pagenavi a:hover {
    border: 1px solid #444;
    color: #444;
    background-color: #eee;
}
.pagenavi span.pages {
    padding: 5px 6px 4px 6px;
    margin: 3px;
    color: #825a2d;
    font-weight:bold;
    border: 1px solid #999;
    background-color: inherit;
}
.pagenavi span.current {
    padding: 5px 6px 4px 6px;
    margin: 3px;
    font-weight:bold;
    border: 1px solid #666;
    color: #444;
    background-color: #eee;
}
.pagenavi span.expand {
    padding: 5px 6px 4px 6px;
    margin: 3px;
    border: 1px solid #ccc;
    color: #444;
    background-color: inherit;
}
.pagenavi .first, .pagenavi .last {
    border: 1px solid #aaa;
}
.pagenavi .single_page {
border: 1px dashed #ccc;
}

Tras esto ya tenemos listo nuestro sistema de paginación, podemos descargar algunos estilos Css desde aquí.

Blog Reacción Estudio

Añadir paginación a WordPress sin ningún plugin.

1) functions.php

2) Reemplazar la navegación

3) Style.css