daffodil

Value Members

1. 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 main class to use is Daffodil to create a Compiler:

   val c = Daffodil.compiler()

   This can then be used to compiled a DFDL schema, and generate a ProcessorFactory:

   val pf = c.compileFile(file)

   This can then be used to create a DataProcessor:

   val dp = pf.onPath("/")

   This can then be used to parse data, returning a ParseResult, which contains the DFDL infoset in either a jdom2 Document or a scala XML Node:

   val pr = dp.parse(data)
   val infoset = pr.result()

   The DataProcessor.parse(java.nio.channels.ReadableByteChannel) method may be called multiple times without the need to create another data processors. For example:

   files.foreach { f => {
     val pr = dp.parse(f)
     val infoset = pr.result()
   }}

   Failures & 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 occured, and any diagnostic information (see Diagnostic) related to the step. thus, before contining, 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 & 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);