Get DateTime
Convenience Method
Declaration
TibrvStatusgetDateTime(
const char* fieldName,
TibrvMsgDateTime& value,
tibrv_u16 fieldId=0);
Purpose
Get the value of a field as an datetime value.
Remarks
This convenience method retrieves a field and extracts its data.
Since it is not possible to convert any other datatype to a datetime value, the field must already contain a datetime. Otherwise, the method returns TIBRV_CONVERSION_FAILED.
Pointer data extracted from the field remain valid until the message is destroyed; that is, even removing the field or updating the field’s value does not invalidate pointer data.
This method produces values that are read-only snapshots of the field data (see Pointer Snapshot). Programs must not modify the datetime value.
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Parameter |
Description |
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Get a field with this name. |
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The program supplies a variable in this parameter, and the method stores the field value in that variable. |
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Get the field with this identifier. Zero is a special value that signifies no field identifier. All non-zero field identifiers must be unique within each message. |
Example
This example code extracts a datetime value from a message field, and converts it to a time_t value. Programs can adapt this code as appropriate. (For corresponding code to convert a time_t value to a datetime value, and add the datetime to a message field, see the example at Add DateTime.)
#include <limits.h>
TibrvStatus getAsTimeT(
TibrvMsg& msg,
const char* field,
time_t& value)
{
TibrvMsgDateTime d;
TibrvStatus error;
error = msg.getDateTime(field,d);
if (error != TIBRV_OK)
return error;
if (d.sec > INT_MAX || d.sec < INT_MIN)
return TIBRV_CONVERSION_FAILED;
value = (time_t)d.sec;
}