class Kramdown::Element

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.

The root of a kramdown element tree has to be an element of type :root. It needs to have certain option keys set so that conversions work correctly. If only a part of a tree should be converted, duplicate the root node and assign the children appropriately, e.g:

root = doc.root
new_root = root.dup
new_root.children = [root.children[0]]  # assign new array with elements to convert

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.
:footnote_count: This key stores the number of actually referenced footnotes 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.

Attributes

children[RW]

The child elements of this element.

type[RW]

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

value[RW]

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

Public Class Methods

category(el) click to toggle source

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.

# File lib/kramdown/element.rb, line 528
def self.category(el)
  CATEGORY[el.type] || el.options[:category]
end

new(type, value = nil, attr = nil, options = nil) click to toggle source

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

# File lib/kramdown/element.rb, line 495
def initialize(type, value = nil, attr = nil, options = nil)
  @type, @value, @attr, @options = type, value, attr, options
  @children = []
end

Public Instance Methods

attr() click to toggle source

The attributes of the element.

# File lib/kramdown/element.rb, line 501
def attr
  @attr ||= {}
end

block?() click to toggle source

syntactic sugar to simplify calls such as +Kramdown::Element.category(el) == :block+ with el.block?.

Returns boolean true or false.

# File lib/kramdown/element.rb, line 536
def block?
  (CATEGORY[type] || options[:category]) == :block
end

options() click to toggle source

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

# File lib/kramdown/element.rb, line 506
def options
  @options ||= {}
end

span?() click to toggle source

syntactic sugar to simplify calls such as +Kramdown::Element.category(el) == :span+ with el.span?.

Returns boolean true or false.

# File lib/kramdown/element.rb, line 544
def span?
  (CATEGORY[type] || options[:category]) == :span
end