uk.ac.starlink.ecsv

Class EcsvTableWriter

java.lang.Object

uk.ac.starlink.table.formats.DocumentedStreamStarTableWriter

uk.ac.starlink.ecsv.EcsvTableWriter

All Implemented Interfaces:

Documented, DocumentedIOHandler, StarTableWriter

public class EcsvTableWriter
extends DocumentedStreamStarTableWriter

TableWriter for ECSV output format. The format currently supported is ECSV 1.0, as documented at Astropy APE6.

The current implementation avoids use of any YAML serialization library, it just uses print statements. This may facilitate its use in some contexts, and doing it like this seems straightforward enough. However if it turns out that the serialization is more complicated or error-prone than I thought it was, it might be worth revisiting this decision and using for instance the serialization facilities of the YAML parser library that is in any case a dependency of this package.

Since:

29 Apr 2020

Author:

Mark Taylor

Field Summary

Fields

Modifier and Type	Field and Description
static EcsvTableWriter	COMMA_WRITER Instance using commas for delimiters.
static EcsvTableWriter	SPACE_WRITER Instance using spaces for delimiters.
static String	TABLENAME_METAKEY Meta map key for table name string value.
static String	UCD_METAKEY Meta map key for UCD string value.
static String	UTYPE_METAKEY Meta map key for Utype string value.
static String	XTYPE_METAKEY Meta map key for Xtype string value.

Constructor Summary

Constructors

Constructor and Description
EcsvTableWriter() Constructs a writer with default characteristics.
EcsvTableWriter(char delimiter, String nameSuffix) Constructs a writer with a given delimiter character.

Method Summary

Modifier and Type	Method and Description
boolean	docIncludesExample() Indicates whether the serialization of some (short) example table should be added to the user documentation for this handler.
char	getDelimiter() Returns the delimiter character, either a space or a comma.
String	getFormatName() Gives the name of the format which is written by this writer.
String	getMimeType() Returns "text/plain".
String	getXmlDescription() Returns user-directed documentation in XML format.
void	setDelimiter(String delimiter) Sets the delimiter.
void	writeStarTable(StarTable table, OutputStream out) Writes a StarTable object to a given output stream.

Methods inherited from class uk.ac.starlink.table.formats.DocumentedStreamStarTableWriter

getExtensions, looksLikeFile, writeStarTable

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface uk.ac.starlink.table.formats.DocumentedIOHandler

matchesExtension, readText, toLink

Field Detail

TABLENAME_METAKEY

public static final String TABLENAME_METAKEY

Meta map key for table name string value.

See Also:

Constant Field Values

UCD_METAKEY

public static final String UCD_METAKEY

Meta map key for UCD string value.

See Also:

Constant Field Values

UTYPE_METAKEY

public static final String UTYPE_METAKEY

Meta map key for Utype string value.

See Also:

Constant Field Values

XTYPE_METAKEY

public static final String XTYPE_METAKEY

Meta map key for Xtype string value.

See Also:

Constant Field Values

SPACE_WRITER

public static final EcsvTableWriter SPACE_WRITER

Instance using spaces for delimiters.

COMMA_WRITER

public static final EcsvTableWriter COMMA_WRITER

Instance using commas for delimiters.

Constructor Detail

EcsvTableWriter

public EcsvTableWriter()

Constructs a writer with default characteristics.

EcsvTableWriter

public EcsvTableWriter(char delimiter,
                       String nameSuffix)

Constructs a writer with a given delimiter character.

Parameters:

delimiter - field delimiter character; should be a space or comma

nameSuffix - string to append to "ECSV" to provide the format name

Method Detail

getFormatName

public String getFormatName()

Description copied from interface: StarTableWriter

Gives the name of the format which is written by this writer. Matching against this string may be used by callers to identify or select this writer from a list.

Returns:

a short string identifying the output format of this writer

getMimeType

public String getMimeType()

Returns "text/plain".

Returns:

MIME content type

docIncludesExample

public boolean docIncludesExample()

Description copied from interface: DocumentedIOHandler

Indicates whether the serialization of some (short) example table should be added to the user documentation for this handler. Binary formats, or instances for which the Documented.getXmlDescription() method already includes some example output, should return false.

Returns:

true if the user documentation would benefit from the addition of an example serialization

getXmlDescription

public String getXmlDescription()

Description copied from interface: Documented

Returns user-directed documentation in XML format.

The output should be a sequence of one or more <P> elements, using XHTML-like XML. Since rendering may be done in a number of contexts however, use of the full range of XHTML elements is discouraged. Where possible, the content should stick to simple markup such as the elements P, A, UL, OL, LI, DL, DT, DD EM, STRONG, I, B, CODE, TT, PRE.

Returns:

XML description of this object

setDelimiter

@ConfigMethod(property="delimiter",
              doc="<p>Delimiter character, which for ECSV may be either a space or a comma. Permitted values are \"<code>space</code>\" or \"<code>comma</code>\".</p>",
              usage="comma|space",
              example="comma")
public void setDelimiter(String delimiter)

Sets the delimiter. ECSV only permits the space or comma.

Parameters:

delimiter - delimiter character; may be "space", "comma", " " or ","

Throws:

IllegalArgumentException - if not one of the permitted values

getDelimiter

public char getDelimiter()

Returns the delimiter character, either a space or a comma.

Returns:

delimiter character

writeStarTable

public void writeStarTable(StarTable table,
                           OutputStream out)
                    throws IOException

Description copied from interface: StarTableWriter

Writes a StarTable object to a given output stream. The implementation can assume that out is suitable for direct writing (for instance it should not normally wrap it in a BufferedOutputStream), and should not close it at the end of the call.

Not all table writers are capable of writing to a stream; an implementation may throw a TableFormatException to indicate that it cannot do so.

Parameters:

table - the table to write

out - the output stream to which startab should be written

Throws:

TableFormatException - if this table cannot be written to a stream

IOException - if there is some I/O error