Dumping and Restoring objects on XML
[XML]

How to dump or restore a CLAM::Component in XML format. More...

Classes
class	CLAM::XmlStorage
	Provides XML format storage for CLAM Component's. More...

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Detailed Description

How to dump or restore a CLAM::Component in XML format.

Any class that derives from Component can be dumped and restored in XML (http://www.w3.org/XML) format. Components includes Arrays, DynamicType, ProcessingConfig, ProcessingData...

Warning:

XML storage is a very expensive task when dealing with big amounts of numeric data.

Dumping and restoring a component in XML

In its simplest usage, you can use the static functions Dump and Restore.

 MyComponent myComponent;

 // Here you can modify your Component

 CLAM::XmlStorage::Dump(myComponent, "Document", "MyComponent.xml")

Later you can restore the component:

 // An unmodified default constructed object!!!
 MyComponent comp;
 try
 {
        CLAM::XmlStorage::Restore(comp, "mycomponent.xml");
 }
 catch (CLAM::XmlStorageErr & err)
 {
        // Handle the error, a dirty way could be:
        std::cerr << err.what() << std::endl;
        exit(-1);
 }

Dump and Restore are overloaded to accept any C++ stream instead of a filename. So, you can also write:

 MyComponent myComponent;
 CLAM::XmlStorage::Dump(myComponent, "Document", std::cout)

You can the AppendToDocument static function to add an object in a given path of an existing XML file, or using RestoreFromFragment to restore the object taking an XML fragment.

Catchable exceptions (CLAM::XmlStorageErr) are thrown on the following conditions:

• The source/target stream could not be open
• The read source contained illegal XML
• The XML is valid but it failed to be mapped to the CLAM objects.
• A step on the path to change the selection couldn't be followed
• A loaded CLAM object failed its own activation constraints.

Author:

David Garcia.