Creating Processor .properties Files

The processors executed by the default EscenicStandardFilterChain are defined in a system file called StandardFilter.properties, which looks something like this:

$class com.escenic.presentation.servlet.LooseFilterChain

## config.1xx  -- reserved for third parties


## config.2xx -- reserved for escenic core resolver filters
config.210 = ./PublicationResolverConfig
config.220 = ./SectionResolverConfig
config.230 = ./ArticleResolverConfig

## config.3xx -- reserved for third parties

## config.4xx -- reserved for escenic core presentation filters
config.400 =  ./PresentationConfig

## config.5xx -- reserved for third parties

## config.6xx -- reserved for escenic core authentication and authorization filters
config.600 = ./PreviewConfig
config.601 = ./AgreementConfig

# config.7xx -- reserved for third parties

# config.8xx -- reserved for escenic core dispatcher filters

config.800 = ./TemplateDispatchConfig

# config.9xx -- reserved for third parties after
#               dispatching in case we didn't dispatch!

This file specifies the names of a series of configuration files, which in turn identify and configure the classes implementing the processors in the chain. The file PublicationResolverConfig.properties, for example, looks like this:

$class = com.escenic.presentation.servlet.LooseFilterChain$FilterChainConfigBuilder

filterName = PublicationResolver

filter = ./PublicationResolverFilter

# must be an absolute path
initParameter.processorName = /com/escenic/servlet/PublicationResolverProcessor

The other files that are involved in configuring the PublicationResolverProcessor are:

PublicationResolverFilter.properties

which contains the following:

$class  =  com.escenic.presentation.servlet.ProcessorFilter

PublicationResolverProcessor.properties

which contains the following:

$class  =  com.escenic.presentation.servlet.PublicationResolverProcessor

publicationName = ${/defaults.publication-name}

As you can see, the last of these files contains a reference to the class which actually implements the processor, com.escenic.presentation.servlet.PublicationResolverProcessor.

In order to insert your own processor into the default chain, you need to create a corresponding set of files of your own. If, for example, you have created a processor class called com.mycompany.mysterious.MysteriousProcessor, and you want to insert it into the processor chain immediately after the standard ArticleResolver processor, then you would need to create the following files:

StandardFilter.properties

which should contain something like:

config.310 = /com/mycompany/mysterious/MysteriousProcessorConfig

This file is merged with the system StandardFilter.properties file by the Content Store. The parameter name config.310 ensures that the processor is executed after the ArticleResolver processor (at slot 230) and before the PresentationProcessor (at slot 400). It is also within the 300-399, which is reserved for use by third-party developers. You should only use slots in these third-party ranges, because then you are sure that your processor will not come into conflict with any standard processor added in later versions of the Content Store.

MysteriousProcessorConfig.properties

which should contain something like:

$class = com.escenic.presentation.servlet.LooseFilterChain$FilterChainConfigBuilder

filterName = Mysterious

filter = ./MysteriousFilter

# must be an absolute path
initParameter.processorName = /com/mycompany/mysterious/MysteriousProcessor

This file has a standard structure and contents. The parts that change from processor to processor are highlighted in bold.

MysteriousFilter.properties

which must contain the following line:

$class  =  com.escenic.presentation.servlet.ProcessorFilter

This file always has exactly the same contents. Its name must match the name specified with the filter parameter in the MysteriousProcessorConfig.properties file.

MysteriousProcessor.properties

which must at least contain the following line:

$class = com.mycompany.mysterious.MysteriousProcessor

If your processor has configuration parameters, then the file can also contain settings for these parameters, for example:

$class = com.mycompany.mysterious.MysteriousProcessor

theAnswer = 42