Package it.unimi.dsi.parser.callback

Class DefaultCallback

  • All Implemented Interfaces:
    Callback
    Direct Known Subclasses:
    LinkExtractor, TextExtractor
    public class DefaultCallback
extends Object
implements Callback
    A default, do-nothing-at-all callback.

    Callbacks can inherit from this class and forget about methods they are not interested in.

    This class has a protected constructor. If you need an instance of this class, use getInstance().

    • Constructor Detail

      • DefaultCallback

        protected DefaultCallback()

    • Method Detail

      • getInstance

        public static DefaultCallback getInstance()
        Returns the singleton instance of the default callback.
        Returns:
        the singleton instance of the default callback.

      • configure

        public void configure​(BulletParser parserUnused)
        Description copied from interface: Callback
        Configure the parser for usage with this callback.

        When a callback is registered with a parser, it needs to set up the parser so that all data required by the callback is actually parsed. The configuration must be a monotone process—you can only set properties and add attribute types to be parsed.

        Specified by:
        configure in interface Callback

      • startDocument

        public void startDocument()
        Description copied from interface: Callback
        Receive notification of the beginning of the document.

        The callback must use this method to reset its internal state so that it can be resued. It must be safe to invoke this method several times.

        Specified by:
        startDocument in interface Callback

      • startElement

        public boolean startElement​(Element elementUnused,
                            Map<Attribute,​MutableString> attrMapUnused)
        Description copied from interface: Callback
        Receive notification of the start of an element.

        For simple elements, this is the only notification that the callback will ever receive.

        Specified by:
        startElement in interface Callback
        Parameters:
        elementUnused - the element whose opening tag was found.
        attrMapUnused - a map from Attributes to MutableStrings.
        Returns:
        true to keep the parser parsing, false to stop it.

      • endElement

        public boolean endElement​(Element elementUnused)
        Description copied from interface: Callback
        Receive notification of the end of an element. Warning: unless specific decorators are used, in general a callback will just receive notifications for elements whose closing tag appears explicitly in the document.

        This method will never be called for element without closing tags, even if such a tag is found.

        Specified by:
        endElement in interface Callback
        Parameters:
        elementUnused - the element whose closing tag was found.
        Returns:
        true to keep the parser parsing, false to stop it.

      • characters

        public boolean characters​(char[] textUnused,
                          int offsetUnused,
                          int lengthUnused,
                          boolean flowBrokenUnused)
        Description copied from interface: Callback
        Receive notification of character data inside an element.

        You must not write into text, as it could be passed around to many callbacks.

        flowBroken will be true iff the flow was broken before text. This feature makes it possible to extract quickly the text in a document without looking at the elements.

        Specified by:
        characters in interface Callback
        Parameters:
        textUnused - an array containing the character data.
        offsetUnused - the start position in the array.
        lengthUnused - the number of characters to read from the array.
        flowBrokenUnused - whether the flow is broken at the start of text.
        Returns:
        true to keep the parser parsing, false to stop it.

      • cdata

        public boolean cdata​(Element elementUnused,
                     char[] textUnused,
                     int offsetUnused,
                     int lengthUnused)
        Description copied from interface: Callback
        Receive notification of the content of a CDATA section.

        CDATA sections in an HTML document are the result of meeting a STYLE or SCRIPT element. In that case, the element will be passed as first argument.

        You must not write into text, as it could be passed around to many callbacks.

        Specified by:
        cdata in interface Callback
        Parameters:
        elementUnused - the element enclosing the CDATA section, or null if the CDATA section was created with explicit markup.
        textUnused - an array containing the character data.
        offsetUnused - the start position in the array.
        lengthUnused - the number of characters to read from the array.
        Returns:
        true to keep the parser parsing, false to stop it.

      • endDocument

        public void endDocument()
        Description copied from interface: Callback
        Receive notification of the end of the document.
        Specified by:
        endDocument in interface Callback