File Information
Library: Data
Package: DataCore
Header: Poco/Data/RowFormatter.h
Description
Row formatter is an abstract class providing definition for row formatting functionality. For custom formatting strategies, inherit from this class and override formatNames() and formatValues() member functions.
Row formatter can be either passed to the RecordSet at construction time, like in the following example:
RecordSet rs(session. "SELECT * FROM Table", new MyRowFormater);
or it can be supplied to the statement as in the following example:
MyRowFormatter rf session << "SELECT * FROM Table", format(rf);
If no formatter is externally supplied to the statement, the SimpleRowFormatter is used. Statement always has the ownership of the row formatter and shares it with rows through RecordSet.
To accomodate for various formatting needs, a formatter can operate in two modes:
- progressive: formatted individual row strings are gemerated and returned from each call to formatValues; std::string& formatNames(const NameVecPtr, std::string&) and std::string& formatValues(const ValueVec&, std::string&) member calls should be used in this case; this is the default mode
- bulk: formatted resulting string is accumulated internally and obtained at the end of iteration via toString() member function; void formatNames(const NameVecPtr) and void formatValues(const ValueVec&) member calls should be used in this case
When formatter is used in conjunction with Row/RecordSet, the formatting members corresponding to the formater mode are expected to be implemented. If a call is propagated to this parent class, the functions do nothing or silently return empty string respectively.
Inheritance
Known Derived Classes: SimpleRowFormatter
Member Summary
Member Functions: formatNames, formatValues, getMode, getTotalRowCount, postfix, prefix, reset, rowCount, setMode, setPostfix, setPrefix, setTotalRowCount, toString
Types Aliases
NameVec
using NameVec = std::vector < std::string >;
NameVecPtr
using NameVecPtr = SharedPtr < std::vector < std::string >>;
Ptr
using Ptr = SharedPtr < RowFormatter >;
ValueVec
using ValueVec = std::vector < Poco::Dynamic::Var >;
Enumerations
Mode
Constructors
RowFormatter
RowFormatter(
const std::string & prefix = "",
const std::string & postfix = "",
Mode mode = FORMAT_PROGRESSIVE
);
Creates the RowFormatter and sets the prefix and postfix to specified values.
Destructor
~RowFormatter 
virtual ~RowFormatter();
Destroys the RowFormatter.
Member Functions
formatNames
virtual std::string & formatNames(
const NameVecPtr pNames,
std::string & formattedNames
);
Should be implemented to format the row fields names and return the formatted string. The default implementation clears the names string and returns it.
formatNames
virtual void formatNames(
const NameVecPtr pNames
);
Should be implemented to format the row fields names. The default implementation does nothing.
formatValues
virtual std::string & formatValues(
const ValueVec & vals,
std::string & formattedValues
);
Should be implemented to format the row fields values and return the formatted string. The default implementation clears the values string and returns it.
formatValues
virtual void formatValues(
const ValueVec & vals
);
Should be implemented to format the row fields values. The default implementation does nothing.
getMode 
Mode getMode() const;
Returns the formater mode.
getTotalRowCount
int getTotalRowCount() const;
Returns zero. Must be implemented by inheriting classes. Typically, total row count shall be set up front through setTotalRowCount() call.
postfix
virtual const std::string & postfix() const;
Returns postfix string;
prefix
virtual const std::string & prefix() const;
Returns prefix string;
reset
void reset();
Resets the formatter by setting prefix and postfix to empty strings and row count to INVALID_ROW_COUNT.
rowCount
virtual int rowCount() const;
Returns INVALID_ROW_COUNT. Must be implemented by inheriting classes which maintain count of processed rows.
setMode
void setMode(
Mode mode
);
Sets the fromatter mode.
setTotalRowCount
void setTotalRowCount(
int count
);
Sets total row count.
toString
virtual const std::string & toString();
Throws NotImplementedException. Formatters operating in bulk mode should implement this member function to return valid pointer to the formatted result.
setPostfix 
void setPostfix(
const std::string & postfix
);
Sets the postfix for the formatter
setPrefix
void setPrefix(
const std::string & prefix
);
Sets the prefix for the formatter.
Variables
INVALID_ROW_COUNT 
static const int INVALID_ROW_COUNT = - 1;