FixedLengthUtil::FixedLengthFileWriter Class Reference

Writer for fixed-length line output files. More...

Inheritance diagram for FixedLengthUtil::FixedLengthFileWriter:

Public Member Methods
	constructor (string file_name, hash specs, *hash opts)
	Instantiates the FixedLengthFileWriter object. More...
string	getFileName ()
	Return the file name (including path, if used)
	write (hash line)
	Renders a single line for a single input record hash to the output file. More...
	write (list lines)
	iterates the input records and writes rendered versions of all input records to the file More...
	write (Qore::AbstractIterator lines)
	iterates the input records and writes rendered versions of all input records to the file More...
Public Member Methods inherited from FixedLengthUtil::FixedLengthAbstractWriter
bool	checkTransition (*string from, *string to)
	A verification function to be called for each line. This method can be overridden to achieve a begin-to-end validation of the whole input file. More...
	constructor (hash specs, *hash opts)
	creates the FixedLengthAbstractWriter object More...
string	formatLine (hash line)
	Formats a single line from a hash describing the record type and its contents. More...
int	linesCount ()
	get processed lines count

Private Member Methods
File	m_file ()
	file object

Private Attributes
string	file
	file name

Detailed Description

Writer for fixed-length line output files.

Example:

#!/usr/bin/env qore

%new-style
%enable-all-warnings
%require-types
%strict-args

%requires FixedLengthUtil

list data = (
    ("type": "type1", "record": {"col1": 11111, "col2": "bb"}),
    ("type": "type2", "record": {"col3": "c", "col4": "ddd", "col5": "31122014"}),
    ("type": "type1", "record": {"col1": 22222, "col2": "gg"}),
);

hash specs = (
    "type1": (
        "col1": ("length": 5, "type": "int"),
        "col2": ("length": 2, "type": "string"),
    ),
    "type2": (
        "col3": ("length": 1, "type": "string"),
        "col4": ("length": 3, "type": "string"),
        "col5": ("length": 8, "type": "date", "format": "DDMMYYYY", "timezone": "Europe/Prague"),
    ),
);

hash global_options = (
    "eol": "\n",
);

FixedLengthFileWriter w(file, specs, global_options);
w.write(data);

See also

• FixedLengthWriter for a stream-based class providing the same functionality as this class in a more generic way

Member Function Documentation

constructor()

FixedLengthUtil::FixedLengthFileWriter::constructor	(	string	file_name,
		hash	specs,
		*hash	opts
	)

Instantiates the FixedLengthFileWriter object.

Parameters

file_name	the output file path
specs	Fixed-length line specification; see Specification Hash for more information
opts	Global options; see Global Options for valid values

write() [1/3]

FixedLengthUtil::FixedLengthFileWriter::write

(

hash

line

)

Renders a single line for a single input record hash to the output file.

Example:

const Spec = (
    "header": (
        "flow_type": ("length": 3, "type": "string"),
        "record_type": ("length": 3, "type": "int", "padding_char": "0"),
        "number_of_records": ("length": 8, "type": "int", "padding_char": "0"),
    ),
);
hash hh = (
    "type": "header",
    "record": (
        "flow_type": "WTS",
        "record_type": "950",
        "number_of_records": 1,
     ),
);
FixedLengthFileWriter w("filename.txt", Spec);
w.write(hh);

Parameters

line

A hash representing input data to be writen to the file; the hash must have the following keys: "type": a string giving the record type (must be defined in Specification Hash given in the constructor) "record": a hash giving the input record to be rendered (with keys as defined in the Record Description Hash for the record identified by the type argument)

Exceptions

INVALID-RECORD	record name (type key in the record hash) not recognized
FIELD-INPUT-ERROR	the input value is too large to render into the output field
RECORD-TRANSITION-ERROR	a record transition error occurred; an invalid record sequence was given in the input data

write() [2/3]

FixedLengthUtil::FixedLengthFileWriter::write

(

list

lines

)

iterates the input records and writes rendered versions of all input records to the file

Example:

FixedLengthFileWriter w(output_file, Spec);
w.write(i);

Parameters

lines

A list of input records; each list value must be a hash with the following keys: "type": a string giving the record type (must be defined in Specification Hash given in the constructor) "record": a hash giving the input record to be rendered (with keys as defined in the Record Description Hash for the record identified by the type argument)

Exceptions

INVALID-RECORD	record name (type key in the record hash) not recognized
FIELD-INPUT-ERROR	the input value is too large to render into the output field
RECORD-TRANSITION-ERROR	a record transition error occurred; an invalid record sequence was given in the input data

write() [3/3]

FixedLengthUtil::FixedLengthFileWriter::write

(

Qore::AbstractIterator

lines

)

iterates the input records and writes rendered versions of all input records to the file

Example:

FixedLengthFileWriter w(output_file, Spec);
w.write(i);

Parameters

lines

An iterator to stream input records; each iterator value must be a hash with the following keys: "type": a string giving the record type (must be defined in Specification Hash given in the constructor) "record": a hash giving the input record to be rendered (with keys as defined in the Record Description Hash for the record identified by the type argument)

Exceptions

INVALID-RECORD	record name (type key in the record hash) not recognized
FIELD-INPUT-ERROR	the input value is too large to render into the output field
RECORD-TRANSITION-ERROR	a record transition error occurred; an invalid record sequence was given in the input data