[lmi-commits] [4782] Add some capabilities that will soon become useful

[Greg Chicares]

Revision: 4782
          http://svn.sv.gnu.org/viewvc/?view=rev&root=lmi&revision=4782
Author:   chicares
Date:     2010-03-16 01:56:25 +0000 (Tue, 16 Mar 2010)
Log Message:
-----------
Add some capabilities that will soon become useful

Modified Paths:
--------------
    lmi/trunk/xml_lmi.cpp
    lmi/trunk/xml_lmi.hpp

Modified: lmi/trunk/xml_lmi.cpp
===================================================================
--- lmi/trunk/xml_lmi.cpp       2010-02-26 02:32:22 UTC (rev 4781)
+++ lmi/trunk/xml_lmi.cpp       2010-03-16 01:56:25 UTC (rev 4782)
@@ -82,6 +82,40 @@
 
 /// Parse an xml stream.
 ///
+/// Precondition: arguments describe an xml string.
+///
+/// Postconditions: member parser_ is a non-null pointer; the object
+/// it points to is valid in that its operator!() returns false.
+///
+/// Throws: std::runtime_error, via fatal_error(), if a precondition
+/// is violated, or if xml-library calls throw an exception derived
+/// from std::exception.
+
+xml_lmi::dom_parser::dom_parser(char const* data, std::size_t length)
+{
+    try
+        {
+        error_context_ = "Unable to parse xml data: ";
+        parser_.reset(new DomParser(data, length));
+        if(0 == parser_.get())
+            {
+            throw std::runtime_error("Parser not initialized.");
+            }
+        if(true == parser_->operator!())
+            {
+            throw std::runtime_error
+                ("Parser failed: " + parser_->get_error_message()
+                );
+            }
+        }
+    catch(std::exception const& e)
+        {
+        fatal_error() << error_context_ << e.what() << LMI_FLUSH;
+        }
+}
+
+/// Parse an xml stream.
+///
 /// XMLWRAPP !! xmlwrapp has no such ctor as
 ///   xml::tree_parser(std::istream&)
 /// Therefore, read the std::istream into a std::string with
@@ -207,6 +241,20 @@
     return document_->get_root_node();
 }
 
+void xml_lmi::xml_document::save(std::string const& filename)
+{
+    bool okay = document_->save_to_file(filename.c_str());
+    if(!okay)
+        {
+        fatal_error()
+            << "Unable to save file '"
+            << filename
+            << "'."
+            << LMI_FLUSH
+            ;
+        }
+}
+
 std::string xml_lmi::xml_document::str()
 {
     std::string s;
@@ -223,6 +271,24 @@
     element.push_back(xml::element(name.c_str(), content.c_str()));
 }
 
+xml::node::const_iterator retrieve_element
+    (xml::element const& parent
+    ,std::string  const& name
+    )
+{
+    xml::node::const_iterator i = parent.find(name.c_str());
+    if(parent.end() == i)
+        {
+        fatal_error()
+            << "Required element '"
+            << name
+            << "' not found."
+            << LMI_FLUSH
+            ;
+        }
+    return i;
+}
+
 std::string get_content(xml::element const& element)
 {
     try

Modified: lmi/trunk/xml_lmi.hpp
===================================================================
--- lmi/trunk/xml_lmi.hpp       2010-02-26 02:32:22 UTC (rev 4781)
+++ lmi/trunk/xml_lmi.hpp       2010-03-16 01:56:25 UTC (rev 4782)
@@ -31,11 +31,11 @@
 #include <boost/scoped_ptr.hpp>
 #include <boost/utility.hpp>
 
-#include <xmlwrapp/node.h> // xml::node::const_iterator
+#include <xmlwrapp/node.h> // (for xml::element)
 
+#include <cstddef>         // std::size_t
 #include <iosfwd>
 #include <string>
-#include <vector>
 
 /// Interface to xmlwrapp.
 
@@ -48,6 +48,7 @@
 
       public:
         dom_parser(std::string const& filename);
+        dom_parser(char const* data, std::size_t length);
         dom_parser(std::istream const&);
         ~dom_parser();
 
@@ -68,6 +69,8 @@
 
         Document const& document() const {return *document_;}
         xml::element& root_node();
+
+        void save(std::string const& filename);
         std::string str();
 
       private:
@@ -81,6 +84,13 @@
         ,std::string const& content
         );
 
+    /// Find an element subnode by name, throwing if it is not found.
+
+    xml::node::const_iterator retrieve_element
+        (xml::element const& parent
+        ,std::string  const& name
+        );
+
     /// Retrieve an xml element's full text-node contents.
     ///
     /// The contents of all text-node children are concatenated.