Magnolia 4.5 reached end of life on June 30, 2016. This branch is no longer supported, see End-of-life policy.
Java filters were introduced in the Java Servlet specification version 2.3. A filter intercepts requests and responses to transform or use the information. Filters typically do not themselves create responses, but instead provide universal functions that can be "attached" to any type of servlet or JSP page.
Since the filter chain is responsible for request handling in Magnolia, the default chain illustrates how filters are used to process requests. This document provides minimal information on filters. For more, see Request processing and filters and the
Don't change the filter order
Magnolia handles incoming requests to display a page through its own filter chain. Filters in the chain are executed in the order in which they are declared until a filter decides that it can fulfil the request.
The first filter in the filter chain is the
. This filter initializes
MgnlContext which is local to the request and available on every further filter. The context provides a lot of useful functions, see
for details. Additionally the
is initialized and populated with:
AggregationState is accessible using
The ContentTypeFilter detects the correct MIME type and sets it in the response header.
The DeviceDetectionFilter detects the type of device requesting content. Device detection is done using the Mobile Detect API.
The CosMultipartRequestFilter checks to see if there are any binary uploads such as form attachments in the request, extracts the binaries and persists them in the JCR.
The UnicodeNormalizationFilter normalizes the current URI to the NFC form that is used internally.
RegistrationFilter checks the validity of the registration of an enterprise installation and delegates to the registration form so that the user can enter the license key. The license is also checked in other parts of the code such as in the STK.
Handles incoming login requests and delegates to login handlers. The handlers are configured under this filter. The LoginFilter checks to verify that user credentials have been authenticated so that only authenticated users can be made active users. Magnolia uses JAAS for authentication. For more information see Security.
Handles incoming activation requests. This filter is the receiving part of the activation process.
Here is example how to use the bypass feature to avoid specific filters. This configuration will only handle requests where the URI starts with
The activation filter is implemented using
ReceiveFilter from the Simple Exchange module. In the Enterprise Edition, the
XAReceiveFilter (included in the ) extends the module
ReceiveFilter to provide transaction related communications with syndicators.
To increase the performance of the site the
replaces text type responses with the gzipped response. The trick in this filter is that it passes a ResponseWrapper instead of the response object it got in the
doFilter(..) call to the filter chain. After all the following filters have been executed, content is extracted from the ResponseWrapper, gzipped and written to the original response.
MultiChannelFilter resolves the channel to use by considering variations of the set channel. Resulting site gets set in ExtendedAggregationState .
SiteMergeFilter merges channel variations with the site definition. The configuration under this filter overrides configuration done in the site definition. The filter sets the site definition in the aggregation state. In the Community Edition, this filter sets the site in the aggregation state. In the Enterprise Edition, the multisite filter can also set the site.
MultiSiteFilter is an Enterprise Edition filter. It detects which site definition should be used. The filter makes site related properties available in the
checks to see if the logout attribute
mgnlLogout is set as a request parameter. If this flag is found, the user will be logged out and the filter chain will restart with the first filter.
handles 401 and 403 HTTP response codes and
AccessDeniedExceptions. The filter renders an appropriate "login form" that can consist of a redirect or anything else.
HttpClientCallbacks with different configuration and behavior can be configured for this filter.
Here are the client callback configurations for the demo-project members area redirect and login form.
Both callback classes implement the HttpClientCallback interface and support their own configuration properties. A custom callback should implement this interface.
The AbstractHttpClientCallback class provides a number of filtering capabilities:
url. Current request URL decoded and without the context path.
originalUrl. Original request URL decoded and without the context path, but not modified by any filter.
For example, in a multisite installation for the request
The Multisite filter removes the first-level node name from the URL.
Prior to Magnolia 4.5, this functionality resided in
ContentSecurityFilter. These filters now merely set an HTTP response code or throw an exception, which is handled here.
The methods provided by the
The CSRF filter checks the HTTP referer header to ensure that the request is not a cross-site request forgery attack. When a possible CSRF attack is detected the user is redirected to the Magnolia login page. The system displays a notification to say that the referer header is required and logs a security warning to the audit log.
If you access Magnolia with a script, set the referer header in your script to ensure the script can access Magnolia. Similarly, if you embed Magnolia content into a different website, disable the CSRF filter or add a voter (see below) that bypasses the CSRF filter for any requests coming from the trusted URL.
The CSRF security filter causes a request to fail if:
The referer header is empty
The host part of the referer header does not match the requested host.
You can bypass the CSRF security filter with a voter. By default, the filter is bypassed if:
/.magnolia. Only AdminCentral URLs are vulnerable to CSRF attacks. Other URLs are not checked.
You can create your own whitelist of referrer domains or URIs using a voter. The filter is bypassed for the whitelisted referrers. In this example we bypass the filter for any requests referred by
<voter node>: Voter parent node. You can name the node for example as
class: Fully-qualified voter class name. See examples below.
headerName: Header you are checking such as
referer. This is not a misspelling.
pattern: Domain or URI pattern compliant to SimpleUrlPattern . The pattern must be present in the header for the filter to be bypassed.
Use these voter classes:
info.magnolia.voting.voters.RequestHeaderPatternSimpleVoter: Checks for a URL pattern compliant to SimpleUrlPattern such as
info.magnolia.voting.voters.RequestHeaderPatternRegexVoter: Checks for a regular expression pattern.
Grants or denies permission to a site when the site is requested through a particular domain name. For example, if you only grant access to the demo-project site through
www.demo-project.com, no other URL can be used to access the content. When a user tries to access one site's content through another site's domain name, the system displays a HTTP 404 error (page not found). See Cross-site security
checks to see if the active user has permission to access the requested URI. In the Enterprise Edition,
SiteUriSecurityFilter (included in the ) extends
UriSecurityFilter to provide site aware functionality.
The following constraints are considered in finding the permissions of the user:
If the user does not have the permission to access the URI then JAAS will provide a login form. This default behavior of the URI security filter can be changed in JAAS configuration.
You can configure your own login form in the URI security filter to replace the default Magnolia login form. The form is configured in
/server/filters/securityCallback/clientCallbacks. Here is an example of a custom form used to grant public users access to a restricted members area. Authentication is delegated to the custom form when a particular URI is accessed.
If you don't grant permission to the custom login form path then a standard Magnolia login form will be displayed, usually on author instance.
The RangeSupportFilter adds support for ranged requests. Ranged requests is used by iPhone and some other clients to stream videos. In contrast to Android phones, iPhone does not support any other method of streaming videos.
The I18nContentSupportFilter detects the requested locale and sets the locale in the aggregation state. The filter rewrites the internal current URI, whether virtual or not. It does not rewrite the URI displayed to the user, however. See Language.
The CacheFilter manages the Magnolia cache.
The cache filter checks if a requested resource is already stored in the cache to avoid recreation of the resource. If the resource is in the cache, then it will be written to the response and the filter chain stops. If the resource is not found in the cache, then a ResponseWrapper which not only writes to the "standard" response, but saves the response is passed to the chain. After the following filters have been executed (and hopefully the requested resource has been created), the content is extracted from the ResponseWrapper and stored in the cache.
The cache filter is part of theand the respective configuration can be found in the cache module configuration.
The VirtualUriFilter checks to see if the requested URI matches to a URI pattern defined in the modules configuration and executes the URI mapping.
The servlets configured in modules are installed in Magnolia's servlets filter chain using the ServletDispatchingFilter as the implementing filter class. If the servlet mapping matches the URI, then the service(..) method of the servlet is called.
Finally we arrive at the filter chain which does the page rendering and delivery. The filters are grouped in this filter chain so they share a co-bypass definition.
handles access to different repositories or workspaces. By default Magnolia is connected with the website workspace. Therefore a request URI is interpreted as the path to a node in the website repository. If you want to address nodes in other workspaces you have to specify a repository mapping in
Where the URI security filter above checked permissions on the URI. The ContentSecurityFilter checks if the current user has permission to access the requested content resource. The following constraints are considered in finding the permissions of the user:
If the user does not have the permission to access the resource then JAAS will provide a login form. This default behavior of the content security filter can be changed in JAAS configuration.
The AggregatorFilter analyses the request and stores the results in the AggregationState . After this filter, every value the aggregation state can have is known.
The InterceptFilter handles administrative requests from AdminCentral like
executes the component model before template rendering. The filter looks for a request parameter containing the UUID of the component to execute. The model can send output in which case page rendering is skipped, or return a URI prefixed by
Provides collaboration information for the main bar in the page editor. The
SoftLockingFilter checks whether the request is an AJAX request to interact with server-side soft locking support and which returns JSON results. Soft locking is an Enterprise Edition feature.
Finally, the RenderingFilter is responsible for delivering the requested resource. If the requested resource is data (e.g. a file) then the data is just copied to the response.