/***********************************************************************//**
* @brief Read observations from XML document
*
* @param[in] xml XML document.
*
* @exception GException::invalid_instrument
* Invalid instrument encountered.
*
* Reads observations from the first observation list that is found in the
* XML document. The decoding of the instrument specific observation
* definition is done within the observation's read() method.
*
* @todo Observation names and IDs are not verified so far for uniqueness.
* This would be required to achieve an unambiguous update of parameters
* in an already existing XML file when using the write method.
***************************************************************************/
void GObservations::read(const GXml& xml)
{
// Get pointer on observation library
GXmlElement* lib = xml.element("observation_list", 0);
// Loop over all observations
int n = lib->elements("observation");
for (int i = 0; i < n; ++i) {
// Get pointer on observation
GXmlElement* obs = static_cast<GXmlElement*>(lib->element("observation", i));
// Get attributes
std::string name = obs->attribute("name");
std::string id = obs->attribute("id");
std::string instrument = obs->attribute("instrument");
// Get model
GObservationRegistry registry;
GObservation* ptr = registry.alloc(instrument);
// If observation is valid then read its definition from XML file
if (ptr != NULL) {
// Read definition
ptr->read(*obs);
// Set attributes
ptr->name(name);
ptr->id(id);
} // endif: observation was valid
// ... otherwise throw an exception
else {
throw GException::invalid_instrument(G_READ, instrument);
}
// Append observation to container
append(*ptr);
// Free model (appending clones the observation)
delete ptr;
} // endfor: looped over all observations
// Return
return;
}
