spiff06

There is no difference. A page is a special kind of post.
'post_type' => 'page'

The first thing to make sure you have no newline characters before or after the PHP tags in wp-config; the <?php tag should be on line 1, and ?> should be the very last characters of the file. If you’re in luck, that will fix it. If not, there may be a plugin conflict.

See here.

Do I simply put that RewriteRule at the very top of my .htacess file? Or does something need to be above it (like RewriteBase and/or RewriteEngine On, etc.)?

Well, after RewriteEngine and RewriteBase, which set up the redirection module in Apache. If you modify the permalink structure in WordPress, which you undoubtedly will if you haven’t already, then place that line just above the WordPress block.

From reading a few articles on how to migrate from Joomla to WP I was made aware of the 301 plugins, but from what I gathered they required me to set up a rule for every unique page request

No, some of them let you use regex as well.

Regular expressions are not that complex conceptually. It’s just that there’s several ways to get the same result, alternate separators for conflicts or clarity, and the need to escape sequences sometimes make it hard to read. Then there’s the backward matching and such options, which can be rather involved. Tools like the Regulator can help a great deal when learning or designing complex regex.

The module provides a function for that: j2wp_do_wp_connect(). It’s called just before the loop, so you don’t need to worry about selecting the database. Then it’s only a question of running the query (around line 408):

foreach ( $j2wp_pages as $j2wp_page )
{
        /* BEGIN Force post id for SEO */
        $current_post_id = $j2wp_page['ID'];
        $query = "INSERT INTO {$j2wp_wp_tb_prefix}post(id) VALUES('$current_post_id')";
        $result = mysql_query($query, $CON);
        if (!$result) {
                echo "Could not create post #$current_post_id<br />";
                echo mysql_error();
        } else {
                echo "Created post #$current_post_id<br />";
        }
        /* END Force post id for SEO */
        $id = wp_insert_post( $j2wp_page );

Not forgetting to add the ID to each page (around line 377):

$j2wp_pages[] = array(
        'ID' => $R->id, /* Force post id for SEO */
        'post_author' => $user_id,
        'post_content' => $post_content,
        'post_date' => $R->created,
        'post_date_gmt' => $R->created,
        'post_modified' => $R->modified,
        'post_modified_gmt' => $R->modified,
        'post_title' => $R->title,
        'post_status' => 'publish',
        'comment_status' => 'open',
        'ping_status' => 'open',
        'post_name' => $R->alias,
        'tags_input' => $R->metakey,
        'post_type' => 'page'
      );

Hopefully that’ll do it.

By the way, this question was asked 3 months ago and was left unresolved. When you do get it to work as required, might want to notify the developer(s) in the appropriate plugin section of these forums.

Crossed posts again.

Answers crossed.

You are correct. Actual inserts are occuring circa line 1097.

So, in the list starting at line 1049, add:

'ID' => $R->id,

Then in the list starting on line 1081:

"ID" => $item['ID']

Give that a try. Truncate wp_posts first.

[As per version 1.5.4 of Joomla to WordPress migrator]

The insertion happens on line 408 in joomla2wp-mig.php:

$id = wp_insert_post( $j2wp_page );

wp_insert_post accepts the ID as a parameter, so all that’s needed is to put an extra key with the Joomla ID in the array.

The array is populated on line 376:

$j2wp_pages[] = array(
        'post_author' => $user_id,
        'post_content' => $post_content,
        'post_date' => $R->created,
        'post_date_gmt' => $R->created,
        'post_modified' => $R->modified,
        'post_modified_gmt' => $R->modified,
        'post_title' => $R->title,
        'post_status' => 'publish',
        'comment_status' => 'open',
        'ping_status' => 'open',
        'post_name' => $R->alias,
        'tags_input' => $R->metakey,
        'post_type' => 'page'
      );

Just add the id to the list (referring to this, and assuming Joomla does indeed use “id” as index field):

'ID' => $R->id,

I believe that making these two changes is all that’s needed to make the script preserve identifiers.

As far as #3 and #4 I think you can still refer to posts via identifier, so if you had a post with, say, id=276 in Joomla, giving WordPress something like ?p=276 will reach the proper location. That’s if your migration preserved identifiers, which presumably it did…

Fiddling with .htaccess should point you in the right direction. For example, if you had Joomla URLs of the form /content/view/2985/33/, the following should work:
RewriteRule ^content\/view\/([0-9]*)/ /?p=$1 [R=301,L]

If your Joomla URLs were formatted like /index.php?view=article&id=2985&itemid=33, then you’ll need to rewrite those as:

RewriteCond %{QUERY_STRING} id\=([0-9]+)
RewriteRule ^ /?p=%1 [R=301,L]

All the above does is use WordPress’s internal id reference (?p=id always works, provided the given id is that of a valid post) to serve the post. The URL is automatically rewritten as per WordPress settings afterwards.

Note you’ll need to add your Joomla legacy URL rules above the WordPress rules in .htaccess. If you had Joomla pages with other formats, you’ll have to set up several rules to cover all cases.

I think that covers it as far as SEO. Google will reach the right page with a code 301 (Moved Permanently), and will update its database with the new WordPress URL.

Hope that helps.

Quick reference:
mod_rewrite wiki

And oops, the above code should be placed inside a plugin file, placed in the plugins directory and activated in the administration area. So you have to enclose the above in the following:

<?php
/*
Plugin Name: e-mail privacy
Plugin URI: http://www.me.com/
Description: Hides private details from comment notification emails, such as IP address and email.
Author: Me
Version: 1.0
Author URI: http://www.me.com/
*/

if ( ! function_exists('wp_notify_postauthor') ) :

etc. etc. etc.

endif;
?>