issue with setting up permalink programmatically

Question

I created a plugin that activate my theme programmatically. I want to set default permalink using programming. It does't seems to work with custom post types. it works well with default custom post type.

I tried it on admin_footer hook with 9999 priority but not helped.

The code i used is:

add_action('admin_footer','default_permalink',9999); 
function default_permalink(){ 
  if(get_option('change_permalink')!= 'post_name_permalink') { 
    global $wp_rewrite;
    $wp_rewrite->set_permalink_structure( '/%postname%/' );
    $wp_rewrite->flush_rules(); 
    if(function_exists('flush_rewrite_rules')){ 
      flush_rewrite_rules(true);
    } //Set default permalink to postname end       
    update_option('change_permalink','post_name_permalink'); 
  }
}

Please help.

Answer 1

Try to do something like this.

<?php
/* 
Plugin Name: My Custom Plugin
Plugin URI: 
Description: 
Author:
Version: 1.0 
Author URI:  
*/

/* Runs when plugin is activated */
register_activation_hook(__FILE__, 'mcp_install'); 

/* Runs on plugin deactivation*/
register_deactivation_hook( __FILE__, 'mcp_remove' );

function mcp_install() {

    //Make sure that .htaccess file is there.
    add_action('init', 'change_permalinks', 20);


    //Activate your theme also.
}

function mcp_remove() {

}

function mcp_change_permalinks() {
    global $wp_rewrite;
    $wp_rewrite->set_permalink_structure('/%postname%/');
    $wp_rewrite->flush_rules();
}

function mcp_custom_init() {
  $labels = array(
    'name' => 'Books',
    'singular_name' => 'Book',
    'add_new' => 'Add New',
    'add_new_item' => 'Add New Book',
    'edit_item' => 'Edit Book',
    'new_item' => 'New Book',
    'all_items' => 'All Books',
    'view_item' => 'View Book',
    'search_items' => 'Search Books',
    'not_found' =>  'No books found',
    'not_found_in_trash' => 'No books found in Trash', 
    'parent_item_colon' => '',
    'menu_name' => 'Books'
  );

  $args = array(
    'labels' => $labels,
    'public' => true,
    'publicly_queryable' => true,
    'show_ui' => true, 
    'show_in_menu' => true, 
    'query_var' => true,
    'rewrite' => array( 'slug' => 'book' ),
    'capability_type' => 'post',
    'has_archive' => true, 
    'hierarchical' => false,
    'menu_position' => null,
    'supports' => array( 'title', 'editor', 'author', 'thumbnail', 'excerpt', 'comments' )
  ); 

  register_post_type( 'book', $args );
}

add_action( 'init', 'mcp_custom_init', 10);

Answer 2

Rewrite rules for custom post types are controlled by their registration arguments (see rewrite in register_post_type() ) and probably shouldn't be modified externally.

Also note that flushing rewrite rules on every page load is extremely bad for performance. That should only be done when they change, such as on activation of your plugin.

Answer 3

do something like this:

function setup_permalinks_by_default() {
    global $wp_rewrite;
    $wp_rewrite->set_permalink_structure('/%postname%/');
    $wp_rewrite->flush_rules();
}
add_action('after_switch_theme', 'setup_permalinks_by_default')

but this - if i'm not mistaken - will not take care of creating the .htaccess file

edit:
missed the part about the custom post type; probably its best to do it at custom post type registration like rarst said;

one other possibility could be to use add_rewrite_rule and add that to above function, more info here:
http://codex.wordpress.org/Rewrite_API/add_rewrite_rule
http://wp.tutsplus.com/tutorials/creative-coding/the-rewrite-api-the-basics/

edit: see milos comment