Several XProc steps are defined as requirements in the "core" subset the XProc specification.
Componize implements core actions like looping, conditional processing, or exception handling.
- p:pipeline
- Declares a pipeline that can be evaluated by the XProc processor. The children declare inputs, outputs, and
options that the pipeline exposes and identify the steps in its subpipeline. A p:pipeline is a simplified form
of step declaration.
- p:for-each
- Compound step that processes a sequence of documents, applying its subpipeline to each document in
turn.
- p:choose
- Multi-container step that selects exactly one of a list of alternative subpipelines based on the evaluation
of XPath expressions.
- p:when
- Specifies one subpipeline guarded by a test expression.
- p:otherwise
- Specifies the default branch. The subpipeline selected if no test expression on any preceding p:when
evaluates to true.
- p:group
- A group encapsulates the behavior of its subpipeline. In a p:try, a group is a non-step wrapper, everywhere
else, it is a compound step.
- p:try
- Specifies a try/catch. It is a multi-container step that isolates a subpipeline, preventing any dynamic
errors that arise within it from being exposed to the rest of the pipeline.
- p:catch
- Identifies the recovery pipeline of a p:try.
- p:input
- Identifies an input port for a step. In some contexts, p:input declares that a port with the specified name
exists and identifies the properties of that port. In other contexts, it provides a connection for a port
declared elsewhere. And in some contexts, it does both.
- p:iteration-source
- Identifies input to a p:for-each.
- p:output
- Identifies an output port, optionally connecting an input for it, if necessary.
- p:option
- Declares an option and may associate a default value with it. The p:option tag can only be used in a
p:declare-step or a p:pipeline (which is a syntactic abbreviation for a step declaration).
- p:with-option
- Provides an actual value for an option when a step is invoked.
- p:with-param
- Used to establish the value of a parameter. The parameter must be given a value when it is used.
- p:declare-step
- Provides the type and signature of an atomic step or pipeline. Declares the inputs, outputs, and options for
all steps of that type.
- p:library
- A collection of step declarations and/or pipeline definitions.
- p:import
- Loads a pipeline or pipeline library, making it available in the pipeline or library which contains the
p:import.
- p:pipe
- Connects an input to a port on another step.
- p:document
- Reads an XML document from a URI.