Class SourceFormatter

java.lang.Object
SourceFormatter
All Implemented Interfaces:
CharStreamSource
public final class SourceFormatter extends Object implements CharStreamSource
Formats HTML source by laying out each non-inline-level element on a new line with an appropriate indent.

Any indentation present in the original source text is removed.

Use one of the following methods to obtain the output:

The output text is functionally equivalent to the original source and should be rendered identically unless specified below.

The following points describe the process in general terms. Any aspect of the algorithm not specifically mentioned here is subject to change without notice in future versions.

  • Every element that is not an inline-level element appears on a new line with an indent corresponding to its depth in the document element hierarchy.
  • The indent is formed by writing n repetitions of the string specified in the IndentString property, where n is the depth of the indentation.
  • The content of an indented element starts on a new line and is indented at a depth one greater than that of the element, with the end tag appearing on a new line at the same depth as the start tag. If the content contains only text and inline-level elements, it may continue on the same line as the start tag. Additionally, if the output content contains no new lines, the end tag may also continue on the same line.
  • The content of preformatted elements such as PRE and TEXTAREA are not indented, nor is the white space modified in any way.
  • Only normal and document type declaration elements are indented. All others are treated as inline-level elements.
  • White space and indentation inside HTML comments, CDATA sections, or any server tag is preserved, but with the indentation of new lines starting at a depth one greater than that of the surrounding text.
  • White space and indentation inside SCRIPT elements is preserved, but with the indentation of new lines starting at a depth one greater than that of the SCRIPT element.
  • If the TidyTags property is set to true, every tag in the document is replaced with the output from its Tag.tidy() method. If this property is set to false, the tag from the original text is used, including all white space, but with any new lines indented at a depth one greater than that of the element.
  • If the CollapseWhiteSpace property is set to true, every string of one or more white space characters located outside of a tag is replaced with a single space in the output. White space located adjacent to a non-inline-level element tag (except server tags) may be removed.
  • If the IndentAllElements property is set to true, every element appears indented on a new line, including inline-level elements. This generates output that is a good representation of the actual document element hierarchy, but is very likely to introduce white space that compromises the functional equivalency of the document.
  • The NewLine property specifies the character sequence to use for each newline in the output document.
  • If the source document contains server tags, the functional equivalency of the output document may be compromised.

Formatting an entire Source object performs a full sequential parse automatically.

  • Constructor Details

    • SourceFormatter

      public SourceFormatter(Segment segment)
      Constructs a new SourceFormatter based on the specified Segment.
      Parameters:
      segment - the segment containing the HTML to be formatted.
      See Also:

  • Method Details

    • writeTo

      public void writeTo(Writer writer) throws IOException
      Description copied from interface: CharStreamSource
      Writes the output to the specified Writer.
      Specified by:
      writeTo in interface CharStreamSource
      Parameters:
      writer - the destination java.io.Writer for the output.
      Throws:
      IOException - if an I/O exception occurs.

    • appendTo

      public void appendTo(Appendable appendable) throws IOException
      Description copied from interface: CharStreamSource
      Appends the output to the specified Appendable object.
      Specified by:
      appendTo in interface CharStreamSource
      Parameters:
      appendable - the destination java.lang.Appendable object for the output.
      Throws:
      IOException - if an I/O exception occurs.

    • getEstimatedMaximumOutputLength

      public long getEstimatedMaximumOutputLength()
      Description copied from interface: CharStreamSource
      Returns the estimated maximum number of characters in the output, or -1 if no estimate is available.

      The returned value should be used as a guide for efficiency purposes only, for example to set an initial StringBuilder capacity. There is no guarantee that the length of the output is indeed less than this value, as classes implementing this method often use assumptions based on typical usage to calculate the estimate.

      Although implementations of this method should never return a value less than -1, users of this method must not assume that this will always be the case. Standard practice is to interpret any negative value as meaning that no estimate is available.

      Specified by:
      getEstimatedMaximumOutputLength in interface CharStreamSource
      Returns:
      the estimated maximum number of characters in the output, or -1 if no estimate is available.

    • toString

      public String toString()
      Description copied from interface: CharStreamSource
      Returns the output as a string.
      Specified by:
      toString in interface CharStreamSource
      Overrides:
      toString in class Object
      Returns:
      the output as a string.

    • setIndentString

      public SourceFormatter setIndentString(String indentString)
      Sets the string to be used for indentation.

      The default value is a string containing a single tab character (U+0009).

      The most commonly used indent strings are "\t" (single tab), " " (single space), "  " (2 spaces), and "    " (4 spaces).

      Parameters:
      indentString - the string to be used for indentation, must not be null.
      Returns:
      this SourceFormatter instance, allowing multiple property setting methods to be chained in a single statement.
      See Also:

    • getIndentString

      public String getIndentString()
      Returns the string to be used for indentation.

      See the setIndentString(String) method for a full description of this property.

      Returns:
      the string to be used for indentation.

    • setTidyTags

      public SourceFormatter setTidyTags(boolean tidyTags)
      Sets whether the original text of each tag is to be replaced with the output from its Tag.tidy() method.

      The default value is false.

      If this property is set to false, the tag from the original text is used, including all white space, but with any new lines indented at a depth one greater than that of the element.

      Parameters:
      tidyTags - specifies whether the original text of each tag is to be replaced with the output from its Tag.tidy() method.
      Returns:
      this SourceFormatter instance, allowing multiple property setting methods to be chained in a single statement.
      See Also:

    • getTidyTags

      public boolean getTidyTags()
      Indicates whether the original text of each tag is to be replaced with the output from its Tag.tidy() method.

      See the setTidyTags(boolean) method for a full description of this property.

      Returns:
      true if the original text of each tag is to be replaced with the output from its Tag.tidy() method, otherwise false.

    • setCollapseWhiteSpace

      public SourceFormatter setCollapseWhiteSpace(boolean collapseWhiteSpace)
      Sets whether white space in the text between the tags is to be collapsed.

      The default value is false.

      If this property is set to true, every string of one or more white space characters located outside of a tag is replaced with a single space in the output. White space located adjacent to a non-inline-level element tag (except server tags) may be removed.

      Parameters:
      collapseWhiteSpace - specifies whether white space in the text between the tags is to be collapsed.
      Returns:
      this SourceFormatter instance, allowing multiple property setting methods to be chained in a single statement.
      See Also:

    • getCollapseWhiteSpace

      public boolean getCollapseWhiteSpace()
      Indicates whether white space in the text between the tags is to be collapsed.

      See the setCollapseWhiteSpace(boolean collapseWhiteSpace) method for a full description of this property.

      Returns:
      true if white space in the text between the tags is to be collapsed, otherwise false.

    • setIndentAllElements

      public SourceFormatter setIndentAllElements(boolean indentAllElements)
      Sets whether all elements are to be indented, including inline-level elements and those with preformatted contents.

      The default value is false.

      If this property is set to true, every element appears indented on a new line, including inline-level elements.

      This generates output that is a good representation of the actual document element hierarchy, but is very likely to introduce white space that compromises the functional equivalency of the document.

      Parameters:
      indentAllElements - specifies whether all elements are to be indented.
      Returns:
      this SourceFormatter instance, allowing multiple property setting methods to be chained in a single statement.
      See Also:

    • getIndentAllElements

      public boolean getIndentAllElements()
      Indicates whether all elements are to be indented, including inline-level elements and those with preformatted contents.

      See the setIndentAllElements(boolean) method for a full description of this property.

      Returns:
      true if all elements are to be indented, otherwise false.

    • setNewLine

      public SourceFormatter setNewLine(String newLine)
      Sets the string to be used to represent a newline in the output.

      The default is to use the same new line string as is used in the source document, which is determined via the Source.getNewLine() method. If the source document does not contain any new lines, a "best guess" is made by either taking the new line string of a previously parsed document, or using the value from the static Config.NewLine property.

      Specifying a null argument resets the property to its default value, which is to use the same new line string as is used in the source document.

      Parameters:
      newLine - the string to be used to represent a newline in the output, may be null.
      Returns:
      this SourceFormatter instance, allowing multiple property setting methods to be chained in a single statement.
      See Also:

    • getNewLine

      public String getNewLine()
      Returns the string to be used to represent a newline in the output.

      See the setNewLine(String) method for a full description of this property.

      Returns:
      the string to be used to represent a newline in the output.