From: bangerth <bangerth@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Mon, 20 Dec 2010 13:57:15 +0000 (+0000)
Subject: Implement the ability to read XML files of parameters.
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b29fe3803cbb4523a374686e4b85bd3d73307dd6;p=dealii-svn.git

Implement the ability to read XML files of parameters.

git-svn-id: https://svn.dealii.org/trunk@23019 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/include/deal.II/base/parameter_handler.h b/deal.II/include/deal.II/base/parameter_handler.h
index 72b14ce920..c2c90671a0 100644
--- a/deal.II/include/deal.II/base/parameter_handler.h
+++ b/deal.II/include/deal.II/base/parameter_handler.h
@@ -1746,6 +1746,23 @@ class ParameterHandler : public Subscriptor
 				      */
     virtual bool read_input_from_string (const char *s);
 
+				     /**
+				      * Read a parameter file in XML
+				      * format. This could be from a file
+				      * originally written by the
+				      * print_parameters() function using the
+				      * XML output style and then modified by
+				      * hand as necessary; or from a file
+				      * written using this method and then
+				      * modified by the graphical parameter
+				      * GUI (see the general documentation of
+				      * this class).
+				      *
+				      * Return whether the read was
+				      * successful.
+				      */
+    virtual bool read_input_from_xml (std::istream &input);
+    
 				     /**
 				      * Clear all contents.
 				      */
diff --git a/deal.II/source/base/parameter_handler.cc b/deal.II/source/base/parameter_handler.cc
index 04d12d4062..18a4b621c1 100644
--- a/deal.II/source/base/parameter_handler.cc
+++ b/deal.II/source/base/parameter_handler.cc
@@ -1141,13 +1141,152 @@ bool ParameterHandler::read_input_from_string (const char *s)
 
       if (!scan_line (line, lineno))
 	status = false;
-    };
+    }
 
   return status;
 }
 
 
 
+namespace
+{
+				   // Recursively go through the 'source' tree
+				   // and see if we can find corresponding
+				   // entries in the 'destination' tree. If
+				   // not, error out (i.e. we have just read
+				   // an XML file that has entries that
+				   // weren't declared in the ParameterHandler
+				   // object); if so, copy the value of these
+				   // nodes into the destination object
+  bool
+  read_xml_recursively (const boost::property_tree::ptree &source,
+			const std::string                 &current_path,
+			const char                         path_separator,
+			boost::property_tree::ptree       &destination)
+  {
+    for (boost::property_tree::ptree::const_iterator p = source.begin();
+	 p != source.end(); ++p)
+      {
+					 // a sub-tree must either be a
+					 // parameter node or a subsection
+	if (p->second.get_optional<std::string>("value"))
+	  {
+					     // make sure we have a
+					     // corresponding entry in the
+					     // destination object as well
+	    const std::string full_path
+	      = (current_path == ""
+		 ?
+		 p->first
+		 :
+		 current_path + path_separator + p->first);
+	    if (destination.get_optional<std::string> (full_path)
+		&&
+		destination.get_optional<std::string> (full_path +
+						       path_separator +
+						       "value"))
+	      {
+						 // set the found parameter in
+						 // the destination argument
+		destination.put (full_path + path_separator + "value",
+				 p->second.get_optional<std::string>("value"));
+		
+						 // this node might have
+						 // sub-nodes in addition to
+						 // "value", such as
+						 // "default_value",
+						 // "documentation", etc. we
+						 // might at some point in the
+						 // future want to make sure
+						 // that if they exist that
+						 // they match the ones in the
+						 // 'destination' tree
+	      }
+	    else
+	      {
+		std::cerr << "The entry <" << full_path
+			  << "> with value <"
+			  << p->second.get<std::string>("value")
+			  << "> has not been declared.";
+		return false;
+	      }
+	  }
+	else
+	  {
+					     // it must be a subsection
+	    const bool result
+	      = read_xml_recursively (p->second,
+				      (current_path == "" ?
+				       p->first :
+				       current_path + path_separator + p->first),
+				      path_separator,
+				      destination);
+
+					     // see if the recursive read
+					     // succeeded. if yes, continue,
+					     // otherwise exit now
+	    if (result == false)
+	      return false;
+	  }
+      }
+
+    return true;
+  }
+}
+
+
+
+bool ParameterHandler::read_input_from_xml (std::istream &in)
+{
+				   // read the XML tree assuming that (as we
+				   // do in print_parameters(XML) it has only
+				   // a single top-level node called
+				   // "ParameterHandler"
+  boost::property_tree::ptree single_node_tree;
+  try
+    {
+      read_xml (in, single_node_tree);
+    }
+  catch (...)
+    {
+      std::cerr << "This input stream appears not to be valid XML"
+		<< std::endl;
+      return false;
+    }
+
+				   // make sure there is a top-level element
+				   // called "ParameterHandler"
+  if (!single_node_tree.get_optional<std::string>("ParameterHandler"))
+    {
+      std::cerr << "There is no top-level XML element called \"ParameterHandler\"."
+		<< std::endl;
+      return false;
+    }
+
+				   // ensure that there is only a single
+				   // top-level element
+  if (std::distance (single_node_tree.begin(), single_node_tree.end()) != 1)
+    {
+      std::cerr << "The top-level XML element \"ParameterHandler\" is "
+		<< "not the only one."
+		<< std::endl;
+      std::cerr << "(There are "
+		<< std::distance (single_node_tree.begin(),
+				  single_node_tree.end())
+		<< " top-level elements.)"
+		<< std::endl;
+      return false;
+    }
+
+				   // read the child elements recursively
+  const boost::property_tree::ptree
+    &my_entries = single_node_tree.get_child("ParameterHandler");
+
+  return read_xml_recursively (my_entries, "", path_separator, *entries);
+}
+
+
+
 void ParameterHandler::clear ()
 {
   entries.reset (new boost::property_tree::ptree());
diff --git a/tests/bits/parameter_handler_read_xml.cc b/tests/bits/parameter_handler_read_xml.cc
new file mode 100644
index 0000000000..e32bfac71a
--- /dev/null
+++ b/tests/bits/parameter_handler_read_xml.cc
@@ -0,0 +1,85 @@
+//----------------------------  parameter_handler_read_xml.cc  ---------------------------
+//    $Id$
+//    Version: $Name$
+//
+//    Copyright (C) 2002, 2003, 2004, 2005, 2010 by the deal.II authors
+//
+//    This file is subject to QPL and may not be  distributed
+//    without copyright and license information. Please refer
+//    to the file deal.II/doc/license.html for the  text  and
+//    further information on this license.
+//
+//----------------------------  parameter_handler_read_xml.cc  ---------------------------
+
+
+// check ParameterHandler::print_parameters (..., XML). have a few
+// names that contain all sorts of weird (for XML) characters
+
+#include "../tests.h"
+#include <base/logstream.h>
+#include <base/parameter_handler.h>
+#include <fstream>
+
+
+int main ()
+{
+  std::ofstream logfile("parameter_handler_read_xml/output");
+  deallog.attach(logfile);
+  deallog.depth_console(0);
+  deallog.threshold_double(1.e-10);
+
+  ParameterHandler prm;
+  prm.declare_entry ("int1",
+		     "1",
+		     Patterns::Integer(),
+		     "doc 1");
+  prm.declare_entry ("int2",
+		     "2",
+		     Patterns::Integer(),
+		     "doc 2");
+  prm.enter_subsection ("ss1");
+  {
+    prm.declare_entry ("double 1",
+		       "1.234",
+		       Patterns::Double(),
+		       "doc 3");
+
+    prm.enter_subsection ("ss2");
+    {
+      prm.declare_entry ("double 2",
+			 "4.321",
+			 Patterns::Double(),
+			 "doc 4");
+    }
+    prm.leave_subsection ();
+  }
+  prm.leave_subsection ();
+
+				   // things with strange characters
+  prm.enter_subsection ("Testing%testing");
+  {
+    prm.declare_entry ("string&list",
+		       "< & > ; /",
+		       Patterns::Anything(),
+		       "docs 1");
+    prm.declare_entry ("int*int",
+		       "2",
+		       Patterns::Integer());
+    prm.declare_entry ("double+double",
+		       "6.1415926",
+		       Patterns::Double(),
+		       "docs 3");
+  }
+  prm.leave_subsection ();
+
+				   // read from XML
+  std::ifstream in ("parameter_handler_read_xml/prm");
+  bool result = prm.read_input_from_xml (in);
+  Assert (result == true, ExcInternalError());
+
+				   // write it out again
+  prm.print_parameters (deallog.get_file_stream(), ParameterHandler::XML);
+  logfile << std::endl;
+
+  return 0;
+}
diff --git a/tests/bits/parameter_handler_read_xml/cmp/generic b/tests/bits/parameter_handler_read_xml/cmp/generic
new file mode 100644
index 0000000000..c9f5c7e983
--- /dev/null
+++ b/tests/bits/parameter_handler_read_xml/cmp/generic
@@ -0,0 +1,3 @@
+
+<?xml version="1.0" encoding="utf-8"?>
+<ParameterHandler><int1><value> 2</value><default_value>1</default_value><documentation>doc 1</documentation><pattern>0</pattern><pattern_description>[Integer range -2147483648...2147483647 (inclusive)]</pattern_description></int1><int2><value> 3</value><default_value>2</default_value><documentation>doc 2</documentation><pattern>1</pattern><pattern_description>[Integer range -2147483648...2147483647 (inclusive)]</pattern_description></int2><ss1><double_201><value> 2.234</value><default_value>1.234</default_value><documentation>doc 3</documentation><pattern>2</pattern><pattern_description>[Double -1.79769e+308...1.79769e+308 (inclusive)]</pattern_description></double_201><ss2><double_202><value> 5.321</value><default_value>4.321</default_value><documentation>doc 4</documentation><pattern>3</pattern><pattern_description>[Double -1.79769e+308...1.79769e+308 (inclusive)]</pattern_description></double_202></ss2></ss1><Testing_25testing><string_26list><value> __&lt; &amp; &gt; ; /</value><default_value>&lt; &amp; &gt; ; /</default_value><documentation>docs 1</documentation><pattern>4</pattern><pattern_description>[Anything]</pattern_description></string_26list><int_2aint><value> __2</value><default_value>2</default_value><documentation/><pattern>5</pattern><pattern_description>[Integer range -2147483648...2147483647 (inclusive)]</pattern_description></int_2aint><double_2bdouble><value> 7.1415926</value><default_value>6.1415926</default_value><documentation>docs 3</documentation><pattern>6</pattern><pattern_description>[Double -1.79769e+308...1.79769e+308 (inclusive)]</pattern_description></double_2bdouble></Testing_25testing></ParameterHandler>
diff --git a/tests/bits/parameter_handler_read_xml/prm b/tests/bits/parameter_handler_read_xml/prm
new file mode 100644
index 0000000000..cad7566e20
--- /dev/null
+++ b/tests/bits/parameter_handler_read_xml/prm
@@ -0,0 +1,4 @@
+
+<?xml version="1.0" encoding="utf-8"?>
+<ParameterHandler><int1><value>2</value><default_value>1</default_value><documentation>doc 1</documentation><pattern>0</pattern><pattern_description>[Integer range -2147483648...2147483647 (inclusive)]</pattern_description></int1><int2><value>3</value><default_value>2</default_value><documentation>doc 2</documentation><pattern>1</pattern><pattern_description>[Integer range -2147483648...2147483647 (inclusive)]</pattern_description></int2><ss1><double_201><value>2.234</value><default_value>1.234</default_value><documentation>doc 3</documentation><pattern>2</pattern><pattern_description>[Double -1.79769e+308...1.79769e+308 (inclusive)]</pattern_description></double_201><ss2><double_202><value>5.321</value><default_value>4.321</default_value><documentation>doc 4</documentation><pattern>3</pattern><pattern_description>[Double -1.79769e+308...1.79769e+308 (inclusive)]</pattern_description></double_202></ss2></ss1><Testing_25testing><string_26list><value>__&lt; &amp; &gt; ; /</value><default_value>&lt; &amp; &gt; ; /</default_value><documentation>docs 1</documentation><pattern>4</pattern><pattern_description>[Anything]</pattern_description></string_26list><int_2aint><value>__2</value><default_value>2</default_value><documentation/>
+<pattern>5</pattern><pattern_description>[Integer range -2147483648...2147483647 (inclusive)]</pattern_description></int_2aint><double_2bdouble><value>7.1415926</value><default_value>6.1415926</default_value><documentation>docs 3</documentation><pattern>6</pattern><pattern_description>[Double -1.79769e+308...1.79769e+308 (inclusive)]</pattern_description></double_2bdouble></Testing_25testing></ParameterHandler>