Redirection

Jun 26, 2006 | Tags: , , , , , | Written by Administrator

Redirection is a WordPress plugin to manage 301 redirections, keep track of 404 errors, and generally tidy up any loose ends your site may have. This is particularly useful if you are migrating pages from an old website, or are changing the directory of your WordPress installation.

Features include:

  • Supports both WordPress-based and Apache-based redirections
  • 404 error monitoring - captures a log of 404 errors and allows you to easily map these to 301 redirects
  • RSS feed for 404 errors
  • Custom 'pass-through' redirections allowing you to pass a URL through to another page, file, or website.
  • Full logs for all redirected URLs
  • Create redirections based upon a URL, browser, referring site, or login status
  • Automatically add a 301 redirection when a post's URL changes
  • Full regular expression support
  • Fully localized
  • Export all redirections to CSV, XML, or Apache .htaccess files
  • Import Apache .htacces files

NOTE: Version 2 is a major rewrite. While the plugin tries its best to retain any existing Redirection configuration it is possible that something may not make it through the upgrade process. As with any upgrade you should make a backup of your database before installing the new version. Remember that I'm not accepting any responsibility for any data loss!

Version History

  • 2.0.11 - Add hebrew translation
  • 2.0.10 - Fix small issues in display with WP 2.7
  • 2.0.8 - Re-fix log delete
  • 2.0.7 - Fix incorrect automatic redirection with static home pages
  • 2.0.6 - Support for wp-load.php

Installation

Installation is just like any WordPress plugin:

  • Download redirection.zip
  • Unzip
  • Upload to redirection directory to /wp-content/plugins on your server
  • Activate the plugin
  • Configure options from Manage ยป Redirection

Note that you must have a permalinks structure setup through WordPress.

You can find full details of installing a plugin on the plugin installation page.

Core Concepts

Redirection uses three core concepts:

  • Modules
  • Groups
  • Redirects

A module consists of many groups, and each group consists of many redirections. A module determines how the redirections will be used, and a group allows you to separate redirections into logical units. A redirection represents an action performed when a particular URL is accessed.

Don't worry, there's more to come!

Modules

At the most basic level, a module determines how redirections are implemented. There are three types of module:

  • WordPress
  • Apache
  • 404 errors

The WordPress module uses WordPress to implement redirections. This means it works for all permalink-enabled sites and so has the greatest compatibility.

The Apache module, as you would expect, uses Apache to implement redirections. This means that each redirection is written to an Apache .htaccess file, giving you better performance than the WordPress module, at the cost of less compatibility and less flexibility (some features, such as redirection statistics, are only available from the WordPress module).

Separate from these is the 404 error module. This uses Redirection to keep track of 404 errors.

Modules

Each module can be exported to CSV, XML, or an Apache .htaccess file. You can also view logs for each module via an RSS feed

WordPress Module

The WordPress module is the default module and provides the most features. The main disadvantage of this module is that each time a URL is redirected it requires WordPress to be loaded (contrast this to the Apache module where a redirection occurs before WordPress loads).

This module is configured as follows:

Wordpress Module

These options are detailed below:

  • Canonical - determine whether the www should be removed or added to your site URL.
  • Strip index - if enabled then any attempt to access a index.php, index.html, or index.asp file will cause an automatic redirection to the same URL, minus the index file.
  • Time Limit - sets a site-wide PHP timeout limit. Useful if something is timing out.
  • Error level - sets the PHP error reporting level. Useful for removing unwanted warnings, or for viewing hidden ones

Apache Module

Rather than using WordPress to provide redirections the Apache module writes data to an Apache .htaccess file. If you site supports these then this will give you the greatest performance, at the cost of losing a few items of functionality. For example, the Apache module provides no statistical information so it is not possible for the Redirection plugin to keep track of how many times a particular redirection has been used.

The module is configured as follows:

Apache Module

The options that differ from the WordPress module are:

  • Location - the location of the .htaccess file. The default will be your site directory
  • Ban IPs - prevents certain IPs from accessing your site
  • Allow IPs - allow certain IPs to access your site
  • Raw .htaccess - add custom rules
  • Site URL - an advanced option which allows you to set the site base URL

Note that when writing to a .htaccess file the Apache module will retain any existing non-WordPress data, so you can still add custom rules.

404 Module

This module is a little different to the others in that it is designed to record 404 errors. Rather than make this a general function, as in previous versions, the power of this module comes from the fact that redirections created inside it will be ignored from the 404 log. In other words, the module records all 404 errors except the specified URLs. Combined with the RSS feed this gives you a lot of options to keep track of errors on your site.

404 Errors

If you do want to ignore a 404 error (for example, you site may not have a favicon.ico and you don't want this recorded) then you should create redirections as normal, but set the action to 'Do nothing'. As for other modules you can create redirections based upon any action or rule, or matching a particular regular expression.

Groups

A group is a logical collection of redirected URLs. You can create as many groups as you wish, and groups can be re-ordered. URLs are matched based not only on the order in which they occur within a group, but the order in which groups occur within a module.

Group Edit

As well as allowing you to collect redirections together, you can also specify whether the redirections within a group are logged.

As an additional configuration option you can select which group an automatically generated URL is put in when a post/page or category is changed.

Using Redirection

The main idea behind Redirection is that you create several URLs that you want to redirect. These URLs are placed within a group, which in turn is placed within a module. The module determines how the URLs are redirected, and the group allows you to logically organise the URLs.

Each URL (or redirection) can be configured to behave in different ways. When creating a redirection there are several pieces of information you must provide:

  • Source URL - This is the original URL that you want to redirect somewhere else
  • Match - This tells the plugin how you want to match the source URL
  • Action - Determines what happens if the URL is matched
  • Regular expression - Tells the plugin that the source URL is a regular expression (i.e. a pattern that may match many URLs)
  • Target URL - most actions have a target URL. This is typically the URL that the user will be redirected to should the pattern match

Create

Note that items can be re-ordered and this may influence which redirection takes effect.

Matching URLs

Matching a URL is a key part of Redirection and consists of a source URL. This URL must exactly match a URL that you want to redirect. For example, your site has the page:

http://yoursite.com/oldpage/that/needs/redirecting/

The source URL for this is: /oldpage/that/needs/redirecting/. The source does not require your website address, and it is only possible to redirect a URL that exists on your website (you cannot redirect an external website, for example).

Advanced users can make use of regular expressions to reduce the number of redirections they need to create. A regular expression is basically a pattern that tells the plugin how to match. For example:

/(\d*)/(\d*)/(.*)

This pattern tells the plugin that you want to match a URL that looks like:

/2007/05/some-url/

That is, the (\d*) indicates a number, and the (.*) a sequence of characters. Regular expressions are a complicated subject and this page will not attempt to give more than a passing overview of using them. If you do need more help then you should take a look at a regular expression website.

Remember that if the source URL is a regular expression then you must enable the regular expression option, otherwise Redirection will just treat you source URL as plain text.

In addition to the source URL you can also specify a match condition:

  • URL only - Only matches the URL (the majority of your redirections will use this)
  • URL and referrer - Matches a URL when the source and referring site matches (i.e. match the URL only when the user came from a certain website)
  • URL and login status - Matches a URL when the source and user's login status matches (i.e. match the URL only when the user is logged in)
  • URL and user agent - Matches a URL when the source and user's browser matches (i.e. when the user is using a particular type of web browser)

These special rules can be both positive and negative. For example, you can match a URL when the user is logged in (and be redirect to one URL), or when the user is not logged in (and be redirected to another URL). This makes it very easy to create custom rules where users are redirected if they are using a particular browser, or if they came from a particular website.

Actions

An action tells Redirection what to do when a source URL is matched:

  • Redirect to URL - The default case and the majority of your redirections will use this
  • Redirect to random post - An esoteric action that may be useful to some people
  • Pass through - An advanced option that allows you to masquerade one URL as another (i.e. when the source URL is accessed it actually displays the contents of another URL without the user being aware)
  • Error (404) - Causes a 404 error to be returned
  • Do nothing - A dummy option that can be used if you just want to track accesses to a URL

Configuration of rules and actions

Depending on the particular combination of action and match rule you may be required to provide further details for a redirection.

Basic URL redirection

You can specify which HTTP code is used to redirect a URL (301, 302, or 307):

Redirect Url

A couple of examples:

  /blog/(.*) => /$1

This will match any URL that starts with /blog/, and will redirect it to the same URL but without /blog/. For example, /blog/2006/10/01/mypost will be redirected to /2006/10/01/mypost.

  /2006/month_d+/(.*) => /2006/$1/$2

This will match any URL that starts /2006/month_, and is then followed by a number. This will be redirected to the same URL, but without month_. For example, /2006/month_1/something will be redirected to /2006/1/something.

To replace a single dash in a URL with a space:

  /tags/(.*?)-(.*?) => /tags/$1%20$2

Redirect to URL by matching user agent

This allows you to configure a redirection to occur when a specific browser (the user agent) is used:

Redirect User Agent

A set of pre-defined user agents is available from the drop-down menu or you can specify your own. The user agent match is always performed using a regular expression.

Two target URLs can be specified, one for if the user agent does match, and one for if it doesn't match.

Redirect to URL by matching referrer

Similar to the user agent rule but this one looks at the referrer. That is, if a user follows a link from another site to yours, the original site is passed along by the browser (unless disabled) to your site so that you know where the user came from. Using this rule you can base your redirections upon this original site.

Redirect to URL by login status

This rule allows you to match a URL based upon the user's WordPress login status. That is, if they are logged into your site.

Support

Please direct all support questions to the Redirection support forum. Any support questions left on this page may not be answered.

Bugs & New Features

A full list of all bugs can be found in the Redirection issue tracker.

A full list of all requested features can be found in the Redirection feature tracker.

Date Current requested features
05 Nov 2008 Track deleted posts
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Comments (page 28 of 48)

  1. Jonathan Bloom :

    Nov 12, 2007 4:49 pm

    I'm using the latest Redirection plugin on WP 2.3. I tried adding a new redirection and everything flashed, but the redirection wasn't added. I see someone else also had this problem in this post.

  2. Tomas Kapler :

    Nov 12, 2007 2:33 pm

    can this plugin support subdomains? I need to set rewrite something.example.com to show content of static page existing on example.com/rewrite (and possibly redirect from /rewrite to rewrite.)

  3. acute accent :

    Nov 11, 2007 1:26 pm

    Hi, I installed the plugin and activated it, but any new redirection was logged. The section Redirections of redirections.php still read "You have no redirections."

    I found that the table wp_redirection in the db had one field less, "sent_to", than the table wp_redirection_log, so I presumed that I had to add it myself:
    > ALTER TABLE wp_redirection ADD sent_to MEDIUMTEXT CHARACTER SET latin1 COLLATE latin1_swedish_ci NULL DEFAULT NULL AFTER url ;
    The admin page at Wordpress still didn't work so I entered the fields manually in the db:
    url: http://acuteaccent.com/nuclear-watch-out/
    301'd to
    sent_to: http://es.acuteaccent.com/transporte-nuclear-en-londres/
    Now the redirection was visible in the admin area, http://acuteaccent.com/wp-admin/edit.php?page=redirection.php, but the url was redirected to the new one with a message "Redirection loop detected (http://acuteaccent.com/nuclear-watch-out/)".

    Wordpress Version 2.3.1

    Thank you!

  4. Raoul :

    Nov 7, 2007 9:49 pm

    Thanks John, will do! Haven't got any regular expression redirects, just simple 301 redirects for posts I've renamed or moved. Will let you know if I find something.

  5. John (author) :

    Nov 7, 2007 9:27 pm

    Raoul, I've not experienced this myself and no one else has reported similar effects, so I would be surprised if Redirection was just causing random 404 errors. Do you have any regular expression redirections which may be accidentally matching things? Are entries appearing in the redirection log to indicate that Redirection has done something? Unfortunately because this is one of those "it only happens when you're not looking" things it's going to be quite hard to track down! The next time it does happen try disabling Redirection and see if the post still 404s. If it does, re-enable Redirection, access the post again, and see if any of the counters on the redirection page increase. Let me know how it goes.

  6. Raoul :

    Nov 6, 2007 10:58 am

    John, I wanted to bring something to your attention. It's quite possible that the Redirection plugin is causing random 404 errors on my site. In other words, a perfectly valid, published post URL will sometimes be redirected to with a 404 error to my home page (which is the default behavior for 404 errors on my site), and will get logged in the Redirection's 404 log. After I open that post in edit mode and save it, the URL becomes valid once more, and redirection no longer takes place. I don't believe this is a WordPress error. I also can't show you specific examples, since I rush to fix any such redirection problems whenever I discover them. It's very important to me that my published content stay accessible, and I can't afford to leave it inaccessible for troubleshooting purposes once I discover such an error.

    Can you please investigate this when you get a chance? It's fairly stressful to discover that a post which you've spent considerable effort on, and which ranks quite high in Google's search results, suddenly gets a 404 error. Thanks!

  7. John (author) :

    Nov 6, 2007 6:16 am

    Redirections from outside your site will have to be handled on the site you are redirecting from - Redirection has no control over this.

  8. John Baker :

    Nov 6, 2007 5:39 am

    Right. Spot on. My ftp program didn't copy it all over to the server.
    The error messages have disappeared now.
    Thanks.
    But still one more problem. I have added a redirection from a site outside of wordpress
    to my wordpress site.
    But when I try accessing the site outside wp, I still go straight to it and no redirection occurs.

  9. John (author) :

    Nov 5, 2007 10:08 am

    John, are you sure you uploaded the plugin as a directory? Double-check that you have the files mentioned in the errors

    Livingston, I do have planned a feature to 'export' the redirections to work directly with Apache. This would effectively be a standalone capability. Just need to find some time!

    Fabian, a WP admin user should be fine for now.

  10. John Baker :

    Nov 2, 2007 4:53 am

    I seem to be having problems. Everything appears to download and install fine, but when I go to manage/redirection to set options I get a corrupted screen which tells me:

    Rendering of admin template /hsphere/local/home/password/johnbakersblog.co.uk/wp-content/plugins/redirection/view/admin/head.php failed

    Rendering of admin template /hsphere/local/home/password/johnbakersblog.co.uk/wp-content/plugins/redirection/view/admin/submenu.php failed

    Rendering of admin template /hsphere/local/home/password/johnbakersblog.co.uk/wp-content/plugins/redirection/view/admin/redirections.php failed

    I can't understand what I must do to overcome this. Can anyone help, please?

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