Packages

•  package root

  org.apache.daffodil.sapi - Provides the classes necessary to compile DFDL schemas, parse and unparse files using the compiled objects, and retrieve results and parsing diagnostics

  Apache Daffodil (incubating) Scala API

  Packages

  org.apache.daffodil.sapi - Provides the classes necessary to compile DFDL schemas, parse and unparse files using the compiled objects, and retrieve results and parsing diagnostics

  org.apache.daffodil.sapi.logger - Provides the classes necessary to receive logging messages from Daffodil.

  org.apache.daffodil.sapi.debugger - Provides the classes necessary to perform parse tracing or create a custom debugger

  Definition Classes

  root

•  package org

  Definition Classes

  root

•  package apache

  Definition Classes

  org

•  package daffodil

  Definition Classes

  apache

•  package sapi

  Provides the classes necessary to compile DFDL schemas, parse and unparse files using the compiled objects, and retrieve results and parsing diagnostics

  Provides the classes necessary to compile DFDL schemas, parse and unparse files using the compiled objects, and retrieve results and parsing diagnostics

  Overview

  The Daffodil object is a factory object to create a Compiler. The Compiler provides a method to compils a provided DFDL schema into a ProcessorFactory, which creates a DataProcessor:

  val c = Daffodil.compiler()
  val pf = c.compileFile(file)
  val dp = pf.onPath("/")

  The DataProcessor provides the necessary functions to parse and unparse data, returning a ParseResult or UnparseResult, respectively. These contain information about the parse/unparse, such as whether or not the processing succeeded any diagnostic information.

  Parse

  The DataProcessor.parse method accepts input data to parse in the form of a InputSourceDataInputStream and an InfosetOutputter to determine the output representation of the infoset (e.g. Scala XML Nodes, JDOM2 Documents, etc.):

  val scalaOutputter = new ScalaXMLInfosetOutputter()
  val is = new InputSourceDataInputStream(data)
  val pr = dp.parse(is, scalaOutputter)
  val node = scalaOutputter.getResult

  The DataProcessor.parse method is thread-safe and may be called multiple times without the need to create other data processors. However, InfosetOutputter's are not thread safe, requiring a unique instance per thread. An InfosetOutputter should call InfosetOutputter.reset before reuse (or a new one should be allocated). For example:

  val scalaOutputter = new ScalaXMLInfosetOutputter()
  files.foreach { f => {
    outputter.reset
    val is = new InputSourceDataInputStream(new FileInputStream(f))
    val pr = dp.parse(is, scalaOutputter)
    val node = scalaOutputter.getResult
  }

  One can repeat calls to parse() using the same InputSourceDataInputStream to continue parsing where the previous parse ended. For example:

  val is = new InputSourceDataInputStream(dataStream)
  val scalaOutputter = new ScalaXMLInfosetOutputter()
  val keepParsing = true
  while (keepParsing) {
    scalaOutputter.reset()
    val pr = dp.parse(is, jdomOutputter)
    ...
    keepParsing = !pr.location().isAtEnd() && !pr.isError()
  }

  Unparse

  The same DataProcessor used for parse can be used to unparse an infoset via the DataProcessor.unparse method. An InfosetInputter provides the infoset to unparse, with the unparsed data written to the provided java.nio.channels.WritableByteChannel. For example:

  val inputter = new ScalaXMLInfosetInputter(node)
  val ur = dp.unparse(inputter, wbc)

  Failures and Diagnostics

  It is possible that failures could occur during the creation of the ProcessorFactory, DataProcessor, or ParseResult. However, rather than throwing an exception on error (e.g. invalid DFDL schema, parse error, etc), these classes extend WithDiagnostics, which is used to determine if an error occurred, and any diagnostic information (see Diagnostic) related to the step. Thus, before continuing, one must check WithDiagnostics.isError. For example:

  val pf = c.compile(file)
  if (pf.isError()) {
    val diags = pf.getDiagnostics()
    diags.foreach { d =>
      System.out.println(d.toString())
    }
    return -1;
  }

  Saving and Reloading Parsers

  In some cases, it may be beneficial to save a parser and reload it. For example, when starting up, it may be quicker to reload an already compiled parser than to compile it from scratch. To save a DataProcessor:

  val dp = pf.onPath("/")
  dp.save(saveFile);

  And to restore a saved DataProcessor:

  val dp = Daffodil.reload(saveFile);
  val pr = dp.parse(data, inputter);

  Definition Classes

  daffodil

•  package debugger

  Provides the classes necessary to perform parse tracing or create a custom debugger

  Provides the classes necessary to perform parse tracing or create a custom debugger

  Overview

  Daffodil comes with one prebuilt debugger, the TraceDebuggerRunner, which outputs verbose information during the parsing processes, which can be used to aid in debugging a DFDL schema. For example, the TraceDebuggerRunner can be use like so:

  val tdr = new TraceDebuggerRunner()
  Daffodil.setDebugger(tdr)

  Additionally, one may create their own debugger runner by implementing the methods in the DebuggerRunner.

  Once the debugger is set, it must then be turned on, like so:

  Daffodil.setDebugging(true);

  Definition Classes

  sapi

•  package infoset

  Defines various classes used control the representation of the infoset for parse and unparse.

  Defines various classes used control the representation of the infoset for parse and unparse. Classes that extend InfosetOutputter are provided to the DataProcessor.parse method to deteremine how to output an infoset. These classes are not guaranteed to be thread-safe. Classes that extend InfosetInputter are provided to the DataProcessor.unparse method to determine how to read in an infoset. A new InfosetOutputter is required for each call to unparse().

  Definition Classes

  sapi

•  package io

  Definition Classes

  sapi

•  package logger

  Provides the classes necessary to receive logging messages from Daffodil.

  Provides the classes necessary to receive logging messages from Daffodil.

  Overview

  Daffodil comes with three prebuilt log writers:

  • ConsoleLogWriter - writes all log messages to stdout
  • FileLogWriter - writes all log messages to file
  • NullLogWriter - drop all log messages

  To use one of these log writers, create and instance of it and pass it to Daffodil.setLogWriter. For example, to write all logs to /var/log/daffodil.log:

  val lw = new FileLogWriter(new File("/var/log/daffodil.log"))
  Daffodil.setLogWriter(lw)

  One may also change the log level using Daffodil.setLoggingLevel, which defaults to LogLevel.Info if not set. For example, to change the log level to LogLevel.Warning:

  Daffodil.setLoggingLevel(LogLevel.Warning);

  Definition Classes

  sapi

• Compiler
• Daffodil
• DataLocation
• DataProcessor
• Diagnostic
• InvalidParserException
• InvalidUsageException
• LocationInSchemaFile
• ParseResult
• ProcessorFactory
• UnparseResult
• ValidationMode
• WithDiagnostics

org.apache.daffodil.sapi

InvalidParserException 