Class: Kramdown::Element

Inherits:
Object
  • Object
show all
Defined in:
lib/kramdown/element.rb

Overview

Represents all elements in the element tree.

kramdown only uses this one class for representing all available elements in an element tree (paragraphs, headers, emphasis, …). The type of element can be set via the #type accessor.

Following is a description of all supported element types.

Note that the option :location may contain the start line number of an element in the source document.

Structural Elements

:root

Category

None

Usage context

As the root element of a document

Content model

Block-level elements

Represents the root of a kramdown document.

The root element contains the following option keys:

:encoding

When running on Ruby 1.9 this key has to be set to the encoding used for the text parts of the kramdown document.

:abbrev_defs

This key may be used to store the mapping of abbreviation to abbreviation definition.

:abbrev_attr

This key may be used to store the mapping of abbreviation to abbreviation attributes.

:options

This key may be used to store options that were set during parsing of the document.

:blank

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

Empty

Represents one or more blank lines. It is not allowed to have two or more consecutive blank elements.

The value field may contain the original content of the blank lines.

:p

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

Span-level elements

Represents a paragraph.

If the option :transparent is true, this element just represents a block of text. I.e. this element just functions as a container for span-level elements.

:header

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

Span-level elements

Represents a header.

The option :level specifies the header level and has to contain a number between 1 and 6. The option :raw_text has to contain the raw header text.

:blockquote

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

Block-level elements

Represents a blockquote.

:codeblock

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

Empty

Represents a code block, i.e. a block of text that should be used as-is.

The value field has to contain the content of the code block.

The option :lang specifies a highlighting language with possible HTML style options (e.g. php?start_inline=1) and should be used instead of a possibly also available language embedded in a class name of the form 'language-LANG'.

:ul

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

One or more :li elements

Represents an unordered list.

:ol

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

One or more :li elements

Represents an ordered list.

:li

Category

Block-level element

Usage context

Inside :ol and :ul elements

Content model

Block-level elements

Represents a list item of an ordered or unordered list.

Note that the first child of a list item must not be a :blank element!

:dl

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

One or more groups each consisting of one or more :dt elements followed by one or more :dd elements.

Represents a definition list which contains groups consisting of terms and definitions for them.

:dt

Category

Block-level element

Usage context

Before :dt or :dd elements inside a :dl elment

Content model

Span-level elements

Represents the term part of a term-definition group in a definition list.

:dd

Category

Block-level element

Usage context

After :dt or :dd elements inside a :dl elment

Content model

Block-level elements

Represents the definition part of a term-definition group in a definition list.

:hr

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

None

Represents a horizontal line.

:table

Category

Block-level element

Usage context

Where block-level elements are expected

Content model

Zero or one :thead elements, one or more :tbody elements, zero or one :tfoot elements

Represents a table. Each table row (i.e. :tr element) of the table has to contain the same number of :td elements.

The option :alignment has to be an array containing the alignment values, exactly one for each column of the table. The possible alignment values are :left, :center, :right and :default.

:thead

Category

None

Usage context

As first element inside a :table element

Content model

One or more :tr elements

Represents the table header.

:tbody

Category

None

Usage context

After a :thead element but before a :tfoot element inside a :table element

Content model

One or more :tr elements

Represents a table body.

:tfoot

Category

None

Usage context

As last element inside a :table element

Content model

One or more :tr elements

Represents the table footer.

:tr

Category

None

Usage context

Inside :thead, :tbody and :tfoot elements

Content model

One or more :td elements

Represents a table row.

:td

Category

Block-level element

Usage context

Inside :tr elements

Content model

As child of :thead/:tr span-level elements, as child of :tbody/:tr and :tfoot/:tr block-level elements

Represents a table cell.

:math

Category

Block/span-level element

Usage context

Where block/span-level elements are expected

Content model

None

Represents mathematical text that is written in LaTeX.

The value field has to contain the actual mathematical text.

The option :category has to be set to either :span or :block depending on the context where the element is used.

Text Markup Elements

:text

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

None

Represents text.

The value field has to contain the text itself.

:br

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

None

Represents a hard line break.

:a

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

Span-level elements

Represents a link to an URL.

The attribute href has to be set to the URL to which the link points. The attribute title optionally contains the title of the link.

:img

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

None

Represents an image.

The attribute src has to be set to the URL of the image. The attribute alt has to contain a text description of the image. The attribute title optionally contains the title of the image.

:codespan

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

None

Represents verbatim text.

The value field has to contain the content of the code span.

:footnote

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

None

Represents a footnote marker.

The value field has to contain an element whose children are the content of the footnote. The option :name has to contain a valid and unique footnote name. A valid footnote name consists of a word character or a digit and then optionally followed by other word characters, digits or dashes.

:em

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

Span-level elements

Represents emphasis of its contents.

:strong

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

Span-level elements

Represents strong importance for its contents.

:entity

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

None

Represents an HTML entity.

The value field has to contain an instance of Kramdown::Utils::Entities::Entity. The option :original can be used to store the original representation of the entity.

:typographic_sym

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

None

Represents a typographic symbol.

The value field needs to contain a Symbol representing the specific typographic symbol from the following list:

:mdash

An mdash character (—)

:ndash

An ndash character (–)

:hellip

An ellipsis (…)

:laquo

A left guillemet (<<)

:raquo

A right guillemet (>>)

:laquo_space

A left guillemet with a space (<< )

:raquo_space

A right guillemet with a space ( >>)

:smart_quote

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

None

Represents a quotation character.

The value field needs to contain a Symbol representing the specific quotation character:

:lsquo

Left single quote

:rsquo

Right single quote

:ldquo

Left double quote

:rdquo

Right double quote

:abbreviation

Category

Span-level element

Usage context

Where span-level elements are expected

Content model

None

Represents a text part that is an abbreviation.

The value field has to contain the text part that is the abbreviation. The definition of the abbreviation is stored in the :root element of the document.

Other Elements

:html_element

Category

Block/span-level element

Usage context

Where block/span-level elements or raw HTML elements are expected

Content model

Depends on the element

Represents an HTML element.

The value field has to contain the name of the HTML element the element is representing.

The option :category has to be set to either :span or :block depending on the whether the element is a block-level or a span-level element. The option :content_model has to be set to the content model for the element (either :block if it contains block-level elements, :span if it contains span-level elements or :raw if it contains raw content).

:xml_comment

Category

Block/span-level element

Usage context

Where block/span-level elements are expected or in raw HTML elements

Content model

None

Represents an XML/HTML comment.

The value field has to contain the whole XML/HTML comment including the delimiters.

The option :category has to be set to either :span or :block depending on the context where the element is used.

:xml_pi

Category

Block/span-level element

Usage context

Where block/span-level elements are expected or in raw HTML elements

Content model

None

Represents an XML/HTML processing instruction.

The value field has to contain the whole XML/HTML processing instruction including the delimiters.

The option :category has to be set to either :span or :block depending on the context where the element is used.

:comment

Category

Block/span-level element

Usage context

Where block/span-level elements are expected

Content model

None

Represents a comment.

The value field has to contain the comment.

The option :category has to be set to either :span or :block depending on the context where the element is used. If it is set to :span, then no blank lines are allowed in the comment.

:raw

Category

Block/span-level element

Usage context

Where block/span-level elements are expected

Content model

None

Represents a raw string that should not be modified. For example, the element could contain some HTML code that should be output as-is without modification and escaping.

The value field has to contain the actual raw text.

The option :category has to be set to either :span or :block depending on the context where the element is used. If it is set to :span, then no blank lines are allowed in the raw text.

The option :type can be set to an array of strings to define for which converters the raw string is valid.

Constant Summary

CATEGORY =

:nodoc:

{}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(type, value = nil, attr = nil, options = nil) ⇒ Element

Create a new Element object of type type. The optional parameters value, attr and options can also be set in this constructor for convenience.



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# File 'lib/kramdown/element.rb', line 488

def initialize(type, value = nil, attr = nil, options = nil)
  @type, @value, @attr, @options = type, value, (Utils::OrderedHash.new.merge!(attr) if attr), options
  @children = []
end

Instance Attribute Details

#childrenObject

The child elements of this element.



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# File 'lib/kramdown/element.rb', line 483

def children
  @children
end

#typeObject

A symbol representing the element type. For example, :p or :blockquote.



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# File 'lib/kramdown/element.rb', line 476

def type
  @type
end

#valueObject

The value of the element. The interpretation of this field depends on the type of the element. Many elements don't use this field.



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# File 'lib/kramdown/element.rb', line 480

def value
  @value
end

Class Method Details

.category(el) ⇒ Object

Return the category of el which can be :block, :span or nil.

Most elements have a fixed category, however, some elements can either appear in a block-level or a span-level context. These elements need to have the option :category correctly set.



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# File 'lib/kramdown/element.rb', line 516

def self.category(el)
  CATEGORY[el.type] || el.options[:category]
end

Instance Method Details

#attrObject

The attributes of the element. Uses an Utils::OrderedHash to retain the insertion order.



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# File 'lib/kramdown/element.rb', line 494

def attr
  @attr ||= Utils::OrderedHash.new
end

#inspectObject

:nodoc:



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# File 'lib/kramdown/element.rb', line 503

def inspect #:nodoc:
  "<kd:#{@type}#{@value.nil? ? '' : ' ' + @value.inspect} #{@attr.inspect}#{options.empty? ? '' : ' ' + @options.inspect}#{@children.empty? ? '' : ' ' + @children.inspect}>"
end

#optionsObject

The options hash for the element. It is used for storing arbitray options.



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# File 'lib/kramdown/element.rb', line 499

def options
  @options ||= {}
end