Oracle ATG Web Commerce - Installed Rule Filters

Installed Rule Filters

The Oracle ATG Web Commerce installation provides the following SiteContextRuleFilter components for identifying a site:

RequestParameterRuleFilter: Evaluates query parameters that supply the site ID and specify whether that site should persist for the remainder of the current session.
URLPatternMatchingRuleFilter: Encapsulates rules for obtaining a site ID from the request URL.
DefaultSiteRuleFilter: Returns the server’s default site ID.

RequestParameterRuleFilter

Based on the class atg.multisite.PushedSiteParamFilter, the component /atg/multisite/RequestParameterRuleFilter is the first rule filter to execute. This filter processes request query parameters that set the current site, and specify it as a sticky site that persists throughout the session of that request. This filter is typically useful for testing and previewing sites that are under development; it should be disabled for production sites.

RequestParameterRuleFilter checks the request URL for two query parameters:

pushSite is set to a site ID, which is returned by the rule filter’s filter() method.
stickySite, if set to setSite, makes the pushSite-specified site sticky for the current session. Unless explicitly reset or unset, the sticky site is used for all subsequent requests during that session.

A sticky site remains valid for the current session until another request URL sets one of the following query parameters:

pushSite specifies another site ID, which becomes the current site. If stickySite is also set to setSite, this SiteContext becomes the new sticky site.
stickySite is set to unsetSite. This unsets the sticky site, and the RequestParameterRuleFilter returns null. The SiteContextPipelineServlet executes subsequent rule filters in its ruleFilters property until one returns a valid site.

RequestParameterRuleFilter is enabled through two properties:

enabled specifies whether the filter is active within the filter chain. If set to false, SiteContextPipelineServlet skips over this filter when processing a request. By default, this property is set to true.
enableStickySite disables sticky site functionality if set to false. The filter remains active and supports use of the pushSite query parameter; it ignores the stickySite query parameter. By default, this property is set to false.
Note: Sticky site functionality is always enabled on preview servers through the SiteURLManager property autoAppendStickySiteParams. For more about the SiteURLManager, see Multisite URL Management later in this chapter.

If desired, you can change the names of the query parameters that RequestParameterRuleFilter expects by setting these properties:

pushSiteParamName
stickySiteParamName

Note: Changing these properties on an asset management or preview server might disrupt preview functionality.

URLPatternMatchingRuleFilter

Based on the class atg.multisite.SiteContextRuleFilter, the filter component /atg/multisite/URLPatternMatchingRulefilter encapsulates rules for obtaining a site ID from a request URL. The filter implements two algorithms for determining the site ID:

Looks up the request URL in a map that is set in the filter’s URLs property, which pairs URLs with site IDs. If the URL maps to a virtual context room, the getPatternMatchingURLForRequest method returns the portion of the URL containing the domain, port an servlet path
The URLs property setting lets a specific server substitute URL-to-site mappings that are otherwise set and managed by the SiteURLManager. This is generally useful for testing purposes, and is not typically used in a production environment.
Passes the request URL to the method SiteURLManager.getSiteIdForURL(). This method obtains a site ID from the Multisite URL Management system, described elsewhere in this chapter.

Several Boolean properties determine whether the URLPatternMatchingRuleFilter is enabled and how it executes:

Property	Description
`enabled`	The filter is enabled.
`enableSimpleAlgorithm`	Use the `URLs` property to look up the URL request.
`enableSiteURLManagerAlgorithm`	Pass the request URL to the SiteURLManager for processing.

By default, all properties are set to true.

URLPatternMatchingRuleFilter also checks the request for the context parameter atg.multisite.URLPatternMatchingEnabled, which the application’s web.xml file can set to true or false. If the parameter is set to false, the filter does not execute and returns null to the SiteContextPipelineServlet. If web.xml omits this context parameter, the URLPatternMatchingRuleFilter behaves as if it were set to true.

DefaultSiteRuleFilter

Based on the class atg.multisite.DefaultSiteContextRuleFilter, the component /atg/multisite/DefaultSiteRuleFilter is configured by a single property, defaultSiteId, which identifies the server’s default site ID. This filter executes after all filters that are specified in the ruleFilters property execute, and only if none of them returns a site ID.