$prerenderap_admin_hook = add_options_page( 'Prerender and Prefetch Settings', 'Prerender and Prefetch', 'manage_options', 'prerenderap', 'prerenderap_options_page' );

// add CSS styles specific to our options page on our options page only

add_action( "admin_head-{$prerenderap_admin_hook}", 'prerenderap_admin_style' );

<style type="text/css">

.prerenderapmiddle{

width:49%;

margin:0;

padding:0;

float:left;

}

.prerenderapmiddleright{

width:35%;

margin-right:5%;

padding:0;

float:right;

}

</style>

<div class="wrap">

<?php screen_icon( 'plugins' ); ?>

<h2>Prerender and Prefetch Setting</h2>

<form action="options.php" method="post">

<?php settings_fields( 'prerenderap_options' ); ?>

<?php do_settings_sections( 'prerenderap' ); ?>

<br />

<input type="submit" name="Submit" class="button-primary" value="<?php esc_attr_e( 'Save' ); ?>" />

</form>

</div>

<?php

register_setting(

'prerenderap_options', // same to the settings_field

'prerenderap', // options name

'prerenderap_validate' // validation callback

);

add_settings_section(

'default', // settings section (a setting page must have a default section, since we created a new settings page, we need to create a default section too)

'Main settings', // section title

'prerenderap_section_text', // text for the section

'prerenderap' // specify the output of this section on the options page, same as in do_settings_section

);

add_settings_field('prerenderap_load', 'Server load to stop','prerenderap_load','prerenderap','default');

add_settings_field('prerenderap_choose', 'Choose method','prerenderap_choose','prerenderap','default');

add_settings_field('prerenderap_blog', // field ID

'Be in blog page', // Field title

'prerenderap_ask', // display callback

'prerenderap', // which settings page?

'default','blog' // which settings section?

);

add_settings_field('prerenderap_blog_refer', 'Refer to...','prerenderap_refer','prerenderap','default','blog');

add_settings_field('prerenderap_single', 'Be in single pages','prerenderap_ask','prerenderap','default','single');

add_settings_field('prerenderap_single_refer', 'Refer to...','prerenderap_refer','prerenderap','default','single');

add_settings_field('prerenderap_frontpage', 'Be in front page','prerenderap_ask','prerenderap','default','frontpage');

add_settings_field('prerenderap_frontpage_refer', 'Refer to...','prerenderap_refer','prerenderap','default','frontpage');

add_settings_field('prerenderap_archive', 'Be in archive page','prerenderap_ask','prerenderap','default','archive');

add_settings_field('prerenderap_archive_refer', 'Refer to...','prerenderap_refer','prerenderap','default','archive');

<div class="prerenderapmiddle">¿What is Prerender and Prefetch? Nice question. It's a new-navigators technique (ok i'm a liar, Mozilla do it from 2003!) that <strong>loads in background the next page you believe the visitor is going to visit</strong>.<br/><br/>

So... What's the improvement? <strong>That page will load pretty fast!</strong> amazingly fast! BOOM!*<br/>In compatible navigators<br/><br/>

And... What are the inconveniences? In every page you have it activated, a visitor with a navigator that supports Prerender or Prefetch (Chrome and Firefox, basically), will load ¡two pages at a time!, it means, ¡double load for the server! (Because of that <strong>you have below a server's load limit setting</strong>) and need for more resources like bandwidth (just be sure you have a powerfull server)<br/><br/>

Mmm... How i know what page is going to enter the visitor? Well, you just have to <strong>statistically figure it out</strong> and configure below. 86.74% chances the default config is ok for a blog kind WordPress. And remember, <strong>you have just a chance</strong>; Per page only one another page will be loaded in background. So, you can set below what page is going to do the Prerender or Prefetch.<br/>

</div>

<div class="prerenderapmiddleright">

<h2>Basics</h2>

<ul><li>Please, <strong>configure "Server load to stop"</strong>, 4.00 is a nice value for a standar not-too-big and not-too-loaded multiprocessor server. If i were you, i will set it at<br/> ( [# of CPUs of the system]-([# of CPUs of the system]*0.25) )<br/>You can know more about this value here <a href="http://en.wikipedia.org/wiki/Load_(computing)">here</a></li>

<li><strong>Prerender</strong> is the Chrome's method, it loads and render all the page. <strong>Prefetch</strong> is the Firefox and maybe-future-standar of HTML5, it just loads the HTML.</li>

</ul>

</div>

$options = get_option( 'prerenderap' );

$load = sys_getloadavg();

echo "<input id=\"prerenderap_load\" type=\"text\" name=\"prerenderap[load]\" value='{$options['load']}' size='3'> Current load ".$load[0];

$options = get_option( 'prerenderap' );

echo "<select id='prerenderap_choose' name='prerenderap[choose]'>";

if ($options['choose'] == 0){ $selected="selected"; } else { $selected=""; }

echo "<option value=\"0\" ".$selected.">Prerender & Prefetch</option>";

if ($options['choose'] == 1){ $selected="selected"; } else { $selected=""; }

echo "<option value=\"1\" ".$selected.">Just Prefetch (Just loads HTML, saves server's load and bandwidth)</option>";

if ($options['choose'] == 2){ $selected="selected"; } else { $selected=""; }

echo "<option value=\"2\" ".$selected.">Just Prerender (¿Why are you gonna do that?)</option>";

echo "</select>";

echo "<hr>";

$options = get_option( 'prerenderap' );

$ppp = get_option('posts_per_page');

$out="";

$out.= "<select id='prerenderap_".$type."_postn' name='prerenderap[".$type."_postn]'>";

$out.= "<option value=\"-1\">-None-</option>";

for ($i=1; $i<=$ppp; $i++){

if ($options[$type.'_postn']==($i-1)){

$selected="selected";

} else {

$selected="";

}

$out.= "<option value=\"".($i-1)."\" ".$selected.">".$i."</option>";

}

$out.= "</select>";

return $out;

$options = get_option( 'prerenderap' );

$option=$type."_refer";

if ($options[$option]==$who){

return "checked";

} else {

return false;

}

$options = get_option( 'prerenderap' );

echo "<input id=\"prerenderap_".$type."_refer\" type=\"radio\" name=\"prerenderap[". $type."_refer]\" value='$taxonomy' ".prerenderap_check_checked($type,$taxonomy).">$taxonomy <br/>";

$args = array(

'show_option_all' => '',

'show_option_none' => '',

'orderby' => 'ID',

'order' => 'ASC',

'show_count' => 0,

'hide_empty' => 1,

'child_of' => 0,

'exclude' => '',

'echo' => 1,

'selected' => $options[$type.'_refer_taxonomy_'.$taxonomy],

'hierarchical' => 0,

'name' => 'prerenderap['.$type.'_refer_taxonomy_'. $taxonomy.']',

'id' => '',

'class' => 'postform',

'depth' => 0,

'tab_index' => 0,

'taxonomy' => $taxonomy,

'hide_if_empty' => false

);

wp_dropdown_categories( $args );

echo "<br/>";

$options = get_option( 'prerenderap' );

if ($options[$type]){

$checked="checked";

}

echo "<input id=\"prerenderap_".$type."\" type=\"checkbox\" name=\"prerenderap[".$type."]\" value='1' $checked>";

$options = get_option( 'prerenderap' );

if ($type=="blog" || $type=="archive" || $type=="search" || $type=="archive" || $type=="tag"){

/*if (!is_singular($type)){ *//*TODO this doesn't works ¿anything clever? */

echo "<input id=\"prerenderap_".$type."_refer\" type=\"radio\" name=\"prerenderap[".$type."_refer]\" value='postn' ".prerenderap_check_checked($type,"postn").">post number... ".prerenderap_postn($type)." <br/>";

}

echo "<input id=\"prerenderap_".$type."_refer\" type=\"radio\" name=\"prerenderap[".$type."_refer]\" value='next' ".prerenderap_check_checked($type,"next").">next post <br/>";

echo "<input id=\"prerenderap_".$type."_refer\" type=\"radio\" name=\"prerenderap[".$type."_refer]\" value='next_pagination' ".prerenderap_check_checked($type,"next_pagination").">next page in pagination <br/>";

if ($type!="blog"){

echo "<input id=\"prerenderap_".$type."_refer\" type=\"radio\" name=\"prerenderap[".$type."_refer]\" value='front' ".prerenderap_check_checked($type,"front").">front page <br/>";

}

if ($type!="home"){

echo "<input id=\"prerenderap_".$type."_refer\" type=\"radio\" name=\"prerenderap[".$type."_refer]\" value='home' ".prerenderap_check_checked($type,"home").">home page <br/>";

}

$taxonomy="category";

prerenderap_taxonomy_select($type,$taxonomy);

$taxonomy="post_tag";

prerenderap_taxonomy_select($type,$taxonomy);

/* TODO : Get from a menu */ // echo "<input id=\"prerenderap_".$type."_refer\" type=\"radio\" name=\"prerenderap[".$type."_refer]\" value='menu' ".prerenderap_check_checked($type,"menu").">menu element <br/>";

echo "<input id=\"prerenderap_".$type."_refer\" type=\"radio\" name=\"prerenderap[".$type."_refer]\" value='defined' ".prerenderap_check_checked($type,"defined").">defined url <input id=\"prerenderap_".$type."_refer\" type=\"text\" name=\"prerenderap[".$type."_refer_defined]\" value='{$options[$type.'_refer_defined']}' ".prerenderap_check_checked($type,"defined").">";

/*if ( !is_numeric($input['blog']) ) {

return $input;