7.6.4 Filter Dependencies - Reference Documentation
Authors: Graeme Rocher, Peter Ledbrook, Marc Palmer, Jeff Brown, Luke Daley, Burt Beckwith, Lari Hotari
Version: 2.3.8
7.6.4 Filter Dependencies
In aFilters
class, you can specify any other Filters
classes that should first be executed using the dependsOn
property. This is used when a Filters
class depends on the behavior of another Filters
class (e.g. setting up the environment, modifying the request/session, etc.) and is defined as an array of Filters
classes.Take the following example Filters
classes:class MyFilters { def dependsOn = [MyOtherFilters] def filters = { checkAwesome(uri: "/*") { before = { if (request.isAwesome) { // do something awesome } } } checkAwesome2(uri: "/*") { before = { if (request.isAwesome) { // do something else awesome } } } } }
class MyOtherFilters { def filters = { makeAwesome(uri: "/*") { before = { request.isAwesome = true } } doNothing(uri: "/*") { before = { // do nothing } } } }
dependsOn
MyOtherFilters. This will cause all the filters in MyOtherFilters whose scope matches the current request to be executed before those in MyFilters. For a request of "/test", which will match the scope of every filter in the example, the execution order would be as follows:
- MyOtherFilters - makeAwesome
- MyOtherFilters - doNothing
- MyFilters - checkAwesome
- MyFilters - checkAwesome2
Filters
classes are enabled and the execution order of filters within each Filters
class are preserved.If any cyclical dependencies are detected, the filters with cyclical dependencies will be added to the end of the filter chain and processing will continue. Information about any cyclical dependencies that are detected will be written to the logs. Ensure that your root logging level is set to at least WARN or configure an appender for the Grails Filters Plugin (org.codehaus.groovy.grails.plugins.web.filters.FiltersGrailsPlugin
) when debugging filter dependency issues.