Virtual URI mapping

Virtual URI mapping is a way to redirect an incoming request to the actual location of the content. Typically, the virtual address does not match the site hierarchy exactly. 

The logic of virtual URI mapping in Magnolia

A given mapping configuration "maps" an incoming URI to a new target URI. It returns a result describing the new URI and the level of match. The following action prefixes are supported for the new URI:

• redirect:
• permanent:
• forward:

to trigger either a temporary redirect, a permanent redirect or a forward, respectively. See the Action prefixes section below for more detailed explanations.

The URIs can be either absolute or relative within the web application in which case the context path is added automatically. For example:

• Relative
  
  fromUri: /winter2016
toUri: forward:/marketing/campaigns/winter2016

• Absolute
  
  fromUri: /winter2016
toUri: forward:https://www.example.com/marketing/campaigns/winter2016.html

The mappings registry

The mappings are delegated to a separate module (virtual-uri) through the info.magnolia.virtualuri.VirtualUriFilter class and are stored in their own registry (VirtualUriRegistry), which allows to reference each mapping also in YAML definition files. All virtual URI mappings can be located via the Definitions app no matter whether they come from JCR or a YAML file:

Alternatively, search the config space with the JCR Browser app.

Where to use virtual mappings

Virtual URIs are commonly used in Internet marketing for:

• Campaigns, events, conferences, shows, vanity URLs
• Microsites
• Landing pages, geo or language specific pages
• Product pages
• Conversion pages
• Downloads
• Coupon codes, special offers
• Abbreviations, shorthands

There are also utility reasons for redirecting URLs, related to day-to-day site maintenance:

• Web pages have moved due to site re-organization. Users still have old URLs in their bookmarks and in search engine indexes. Without redirection traffic would be lost.
• Registering alternative domain extensions like example.net and example.org and redirecting them to your primary site example.com. You can map multiple domain names to a site in your Magnolia site definition. This can be a major time-saver for a CMS team since there is no need to configure a Web server. Note that you need to register the domains with a registrar first and make sure that DNS entries for the domains point to the server hosting your Magnolia instance.

As an example of mapping, see also Turning a template-based JSON provider into a RESTful API with virtualURIMapping where we define a custom virtual mapping to rewrite a path like /getjson/tours/magnolia-travels/Kyoto into /getjson?workspace=tours&path=/magnolia-travels/Kyoto.

Configuration

You can create virtual URI mappings in the virtualUriMappings folder inside your module configuration. 

Via JCR

Example: A mapping named enterprise-edition forwards users from example.com/ee to example.com/enterprise-edition. The DefaultVirtualUriMapping class (for description see the Mapping classes section below) maps one URI to another. This ensures that external links that point to example.com/ee still work when the target page is renamed.

Via YAML

You can configure virtual URI mappings in a YAML definition file inside a light module folder:

class: info.magnolia.virtualuri.mapping.DefaultVirtualUriMapping
fromUri: /ee
toUri: forward:/enterprise-edition

Properties

A catalog of mappings

For easier orientation, if you have to configure a lot of mappings, you can store them in folder-like structures rather than in one long flat list of mappings:

Mapping classes

Magnolia provides seven ready-made classes that perform virtual URI mapping:

• info.magnolia.virtualuri.mapping.*
  
  • DefaultVirtualUriMapping maps a virtual URI to a content path. This is the simplest and most common type.
    If the URI starts with a dot (.), it is not taken as a wildcard anymore but the dot in fact is interpreted as dot. If you need a wildcard, use ? instead.
  • RegexpVirtualUriMapping allows you to specify a regular expression pattern that matches a sequence of characters. A regexp pattern can match a variety of URIs, which saves time and effort as you would otherwise have to create default mappings for each case. toUri can contain back references to the regexp matches.

  • RotatingVirtualUriMapping is an extension of RegexpVirtualUriMapping that allows rotation between different destination URIs. In order to rotate, toUri must contain an asterisk character * that will be replaced by a random integer between start (default is 1) and end minus one (default is 3). An additional property padding specifies the desired width of the string. Zeroes are added to the left of the integer to make all strings equally wide. Default width is 2.

  • HostBasedVirtualUriMapping forwards the request to a different URI depending on the requested host name.
  • HostBasedRegexpVirtualUriMapping combines the host-based and regex mappings, i.e. forwards the request to a different URI depending on the requested host name and allows you to specify a regular expression pattern that matches a sequence of characters.
• info.magnolia.multisite.mapping.* 
  
  • MultiSiteRootVirtualUriMapping is a special class which specifies the root of a site if site matching returns null. 
  • MultiSiteRegexpVirtualUriMapping adds a site condition to the mapURI check. A mapping will only match the request if both the specified regular expression and the specified site match.

You can also write your own implementation.

The patterns for regular expressions in the regex-based classes are defined in java.util.regex.Pattern.

Action prefixes

You can use these action prefixes:

• forward hides the true target URL from the visitor. The URL that the user typed in the browser address bar or the link they clicked remains visible. Forward is performed internally by the servlet. Any browser reload of the resulting page will repeat the original request, with the original URL.
• redirect displays the true target URL in the address bar. It is a two-step process where the web application instructs the browser to fetch a second URL which differs from the original. A browser reload of the second URL will not repeat the original request but will rather fetch the second URL. Redirect is marginally slower than a forward since it requires two browser requests instead of one. A redirect returns HTTP status code 302 "found" to the client. While OK for human visitors, this method can be suboptimal from search engine optimization (SEO) viewpoint as search engines do not transfer the page rank assigned to the old URL to the new URL.
• permanent 301 redirect is a search engine friendly option. In this case the HTTP response code is set to 301. Google and Yahoo! specifically endorse this type of redirection and Bing is following the trend. 301 redirect preserves your search engine ranking for the redirected page.

It is also possible to leave the action prefix out. A virtual URI mapping that does not have a prefix does not re-process the request. It just changes the current URI in the AggregationState.

Examples

Default

Forward from /winter2016 to /marketing/campaigns/winter2016.

Regular expression

Take requested page name and pass it as a productId request parameter to a product detail page.

The pattern [0-9a-zA-Z-] in fromUri means "any single character in the range of 0-9 or a-z or A-Z or the character - literally". The plus character makes this a greedy pattern that matches one or more of the preceding tokens and will match as many characters as possible before satisfying the next token. By enclosing the pattern in parentheses we create a capturing group ([0-9a-zA-Z-]+) which can be referenced in the toUri using $1.

These request URIs:

• example.com/products/Wayfarer-Retro.html
• example.com/products/B00LBFSSYI.html
• example.com/products/Sony-MDRZX100.html

would be mapped to these URIs:

• example.com/product/detail.html?productId=Wayfarer-Retro

• example.com/product/detail.html?productId=B00LBFSSYI

• example.com/product/detail.html?productId=Sony-MDRZX100

Rotating

A request URI such as forward:/banner/image_*.jpg will randomly forward the request to /banner/image_01.jpg, /banner/image_02.jpg or /banner/image_03.jpg. A use case for this class is rotating images such as banner ads. The mapping displays a random ad on each page visit.

In addition to randomized ad distribution, the class allows you to do basic A/B or multivariate testing. For example, create two images: A and B. Configure the mapping to display them randomly. Track visitor click-through rates to find out which image is more effective.

Host based

Forward the visitor to a German language version of the home page when the site is requested with the .de country domain. Similarly, forward to a French version when the site is requested with the .fr country domain. The matching pattern is in the host property. The toUri value under the parent node works as a fallback option. If no hostname match is found, such as when the site is requested with acme.com, forward to an English version.

Mappings in the default installations of Magnolia