uk.ac.starlink.table.formats

## Class CsvTableBuilder

- java.lang.Object
- - uk.ac.starlink.table.formats.DocumentedTableBuilder
  - - uk.ac.starlink.table.formats.RowEvaluatorTableBuilder
    - - uk.ac.starlink.table.formats.CsvTableBuilder

- All Implemented Interfaces:
    Documented, DocumentedIOHandler, TableBuilder

      public class CsvTableBuilder
      extends RowEvaluatorTableBuilder

  A table builder which reads tables in Comma-Separated Values format. The detailed format of input file which is understood is documented fully in the `CsvStarTable` class.
  Since:
    21 Sep 2004

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `CsvTableBuilder()`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    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.
    `java.lang.String` | `getFormatName()` Returns the name of the format which can be read by this handler.
    `java.lang.Boolean` | `getHasHeader()` Returns header interpretation policy.
    `java.lang.String` | `getXmlDescription()` Returns user-directed documentation in XML format.
    `StarTable` | `makeStarTable(DataSource datsrc, boolean wantRandom, StoragePolicy policy)` Constructs a `StarTable` based on a given `DataSource`.
    `void` | `setDelimiter(char delimiter)` Sets the delimiter character.
    `void` | `setHasHeader(java.lang.Boolean hasHeader)` Sets whether input CSV files are known to include the optional header line or not.

    - ### Methods inherited from class uk.ac.starlink.table.formats.RowEvaluatorTableBuilder

      `canImport, canStream, getDecoders, getMaxSample, setDecoderExcludeList, setDecoders, setMaxSample, streamStarTable`

    - ### Methods inherited from class uk.ac.starlink.table.formats.DocumentedTableBuilder

      `getExtensions, looksLikeFile`

    - ### 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`

- - ### Constructor Detail

    - #### CsvTableBuilder

          public CsvTableBuilder()

  - ### Method Detail

    - #### getFormatName

          public java.lang.String getFormatName()

      Description copied from interface: `TableBuilder`
      Returns the name of the format which can be read by this handler. Matching against this string may be used by callers to identify or select this handler from a list.
      Returns:
        one-word description of this handler's format

    - #### makeStarTable

          public StarTable makeStarTable(DataSource datsrc,
                                         boolean wantRandom,
                                         StoragePolicy policy)
                                  throws TableFormatException,
                                         java.io.IOException

      Description copied from interface: `TableBuilder`
      Constructs a `StarTable` based on a given `DataSource`. If the source is not recognised or this builder does not know how to construct a table from it, then a `TableFormatException` should be thrown. If this builder thinks it should be able to handle the source but an error occurs during processing, an `IOException` can be thrown.

      The `wantRandom` parameter is used to indicate whether, ideally, a random-access table should be returned. There is no requirement for the builder to honour this request, but if it knows how to make both random and non-random tables, it can use this flag to decide which to return.

      Note: the presence of the `wantRandom` parameter is somewhat misleading. TableBuilder implementations usually should, and do, ignore it (it would be removed from the interface if it were not for backward compatibility issues). Regardless of the value of this parameter, implementations should return a random-access table only if it is easy for them to do so; in particular they should not use the supplied `storagePolicy`, or any other resource-expensive measure, to randomise a sequential table just because the `wantRandom` parameter is true.

      Parameters:
        `datsrc` - the DataSource containing the table resource
        `wantRandom` - whether, preferentially, a random access table should be returned
        `policy` - a StoragePolicy object which may be used to supply scratch storage if the builder needs it
      Returns:
        a StarTable made out of `datsrc`
      Throws:
        `TableFormatException` - if the table is not of a kind that can be handled by this handler
        `java.io.IOException` - if an unexpected I/O error occurs during processing

    - #### 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 java.lang.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

    - #### setHasHeader

          @ConfigMethod(property="header",
                        doc="<p>Indicates whether the input CSV file contains the\noptional one-line header giving column names.\nOptions are:\n<ul>\n<li><code>true</code>: the first line is a header line containing column names</li>\n<li><code>false</code>: all lines are data lines, and column names will be assigned automatically</li>\n<li><code>null</code>: a guess will be made about whether the first line is a header or not depending on what it looks like</li>\n</ul>\nThe default value is <code>null</code> (auto-determination).\nThis usually works OK, but can get into trouble if\nall the columns look like string values.\n</p>",
                        usage="true|false|null",
                        example="true",
                        sequence=1)
          public void setHasHeader(java.lang.Boolean hasHeader)

      Sets whether input CSV files are known to include the optional header line or not.
      Parameters:
        `hasHeader` - true if input files are known to contain column names as the first line; false if they are known not to; null to auto-detect

    - #### getHasHeader

          public java.lang.Boolean getHasHeader()

      Returns header interpretation policy.
      Returns:
        true if input files are known to contain column names as the first line; false if they are known not to; null to auto-detect

    - #### setDelimiter

          @ConfigMethod(property="delimiter",
                        doc="<p>Field delimiter character, by default a comma. Permitted values are a single character like \"<code>|</code>\", a hexadecimal character code like \"<code>0x7C</code>\", or one of the names \"<code>comma</code>\", \"<code>space</code>\" or \"<code>tab</code>\". Some choices of delimiter, for instance whitespace characters, might not work well or might behave in surprising ways.</p>",
                        example="|",
                        sequence=2)
          public void setDelimiter(char delimiter)

      Sets the delimiter character. Non-comma delimiters are not guaranteed to work.
      Parameters:
        `delimiter` - delimiter character

    - #### getDelimiter

          public char getDelimiter()

      Returns the delimiter character.
      Returns:
        delimiter