NAME Pandoc::Elements - create and process Pandoc documents SYNOPSIS The output of this script "hello.pl" use Pandoc::Elements; use JSON; print Document({ title => MetaInlines [ Str "Greeting" ] }, [ Header( 1, attributes { id => 'top' }, [ Str 'Hello' ] ), Para [ Str 'Hello, world!' ], ])->to_json; can be converted for instance to HTML with via ./hello.pl | pandoc -f json -t html5 --standalone an equivalent Pandoc Markdown document would be % Greeting # Gruß {.de} Hello, world! DESCRIPTION Pandoc::Elements provides utility functions to create abstract syntax trees (AST) of Pandoc documents. Pandoc can convert the resulting data structure to many other document formats, such as HTML, LaTeX, ODT, and ePUB. Please make sure to use at least Pandoc 1.12 when processing documents See also module Pandoc::Filter, command line scripts pandocwalk and pod2pandoc, and the internal modules Pandoc::Walker, Pandoc::Filter::Lazy, and Pod::Simple::Pandoc. EXPORTED FUNCTIONS The following functions and keywords are exported by default: * Constructors for all Pandoc document element (block elements such as "Para" and inline elements such as "Emph", metadata elements and the "Document" in DOCUMENT ELEMENT). * Type keywords such as "Decimal" and "LowerAlpha" to be used as types in other document elements. * The helper following functions "pandoc_json", "attributes", "citation", and "element". pandoc_json $json Parse a JSON string, as emitted by pandoc in JSON format. This is the reverse to method "to_json" but it can read both old (before Pandoc 1.16) and new format. attributes { key => $value, ... } Maps a hash reference or instance of Hash::MultiValue into an attributes list with id, classes, and ordered key-value pairs. The special keys "id" (string), and "class" (string or array reference with space-separated class names) are recognized. You can always manually create an attributes structure: [ $id, [ @classes ], [ [ key => $value ], ... ] ] See also attribute methods to get and set element attributes. citation { ... } A citation as part of document element Cite must be a hash reference with fields "citationID" (string), "citationPrefix" (list of inline elements) "citationSuffix" (list of inline elements), "citationMode" (one of "NormalCitation", "AuthorInText", "SuppressAuthor"), "citationNoteNum" (integer), and "citationHash" (integer). The helper method "citation" can be used to construct such hash by filling in default values and using shorter field names ("id", "prefix", "suffix", "mode", "note", and "hash"): citation { id => 'foo', prefix => [ Str "see" ], suffix => [ Str "p.", Space, Str "42" ] } # in Pandoc Markdown [see @foo p. 42] element( $name => $content ) Create a Pandoc document element of arbitrary name. This function is only exported on request. ELEMENTS Document elements are encoded as Perl data structures equivalent to the JSON structure, emitted with pandoc output format "json". All elements are blessed objects that provide the following element methods and additional accessor methods specific to each element. ELEMENT METHODS to_json Return the element as JSON encoded string. The following are equivalent: $element->to_json; JSON->new->utf8->canonical->convert_blessed->encode($element); Note that the JSON format changed from Pandoc 1.15 to Pandoc 1.16 by introduction of attributes to Link and Image elements. Since Pandoc::Elements 0.16 the new format is serialized by default. Set the package variable or environment variable "PANDOC_VERSION" to 1.15 or below to use the old format. name Return the name of the element, e.g. "Para" for a paragraph element. content Return the element content. For most elements (Para, Emph, Str...) the content is an array reference with child elements. Other elements consist of multiple parts; for instance the Link element has attributes ("attr", "id", "class", "classes", "keyvals") a link text ("content") and a link target ("target") with "url" and "title". is_block True if the element is a Block element is_inline True if the element is an inline Inline element is_meta True if the element is a Metadata element is_document True if the element is a Document element walk(...) Walk the element tree with Pandoc::Walker query(...) Query the element to extract results with Pandoc::Walker transform(...) Transform the element tree with Pandoc::Walker string Returns a concatenated string of element content, leaving out all formatting. ATTRIBUTE METHODS Elements with attributes (element accessor method "attr") also provide the getter methods "id", "classes", "class", "keyvals", and setter methods "id", "class", "keyvals", "add_attribute". Method "keyvals" returns a copy of id, class, and attribute key-value pairs as Hash::MultiValue. If used as setter, all key-value pairs (and optionally id and class if given) are replaced. BLOCK ELEMENTS BlockQuote Block quote, consisting of a list of blocks ("content") BlockQuote [ @blocks ] BulletList Unnumbered list of items ("content"="items"), each a list of blocks BulletList [ [ @blocks ] ] CodeBlock Code block (literal string "content") with attributes ("attr", "id", "class", "classes", "keyvals") CodeBlock $attributes, $content DefinitionList Definition list, consisting of a list of pairs ("content"="items"), each a term ("term", a list of inlines) and one or more definitions ("definitions", a list of blocks). DefinitionList [ @definitions ] # each item in @definitions being a pair of the form [ [ @inlines ], [ @blocks ] ] Div Generic container of blocks ("content") with attributes ("attr", "id", "class", "classes", "keyvals"). Div $attributes, [ @blocks ] Header Header with "level" (integer), attributes ("attr", "id", "class", "classes", "keyvals"), and text ("content", a list of inlines). Header $level, $attributes, [ @inlines ] HorizontalRule Horizontal rule HorizontalRule Null Nothing Null OrderedList Numbered list of items ("content"="items"), each a list of blocks), preceded by list attributes (start number, numbering style, and delimiter). OrderedList [ $start, $style, $delim ], [ [ @blocks ] ] Supported styles are "DefaultStyle", "Example", "Decimal", "LowerRoman", "UpperRoman", "LowerAlpha", and "UpperAlpha". Supported delimiters are "DefaultDelim", "Period", "OneParen", and "TwoParens". Para Paragraph, consisting of a list of Inline elements ("content"). Para [ $elements ] Plain Plain text, not a paragraph, consisting of a list of Inline elements ("content"). Plain [ @inlines ] RawBlock Raw block with "format" and "content" string. RawBlock $format, $content Table Table, with "caption", column "alignments", relative column "widths" (0 = default), column "headers" (each a list of blocks), and "rows" (each a list of lists of blocks). Table [ @inlines ], [ @alignments ], [ @width ], [ @headers ], [ @rows ] Possible alignments are "AlignLeft", "AlignRight", "AlignCenter", and "AlignDefault". An example: Table [Str "Example"], [AlignLeft,AlignRight], [0.0,0.0], [[Plain [Str "name"]] ,[Plain [Str "number"]]], [[[Plain [Str "Alice"]] ,[Plain [Str "42"]]] ,[[Plain [Str "Bob"]] ,[Plain [Str "23"]]]]; INLINE ELEMENTS Cite Citation, a list of "citations" and a list of inlines ("content"). See helper function "citation" in citation to construct citations. Cite [ @citations ], [ @inlines ] Code Inline code, a literal string ("content") with attributes ("attr", "id", "class", "classes", "keyvals") Code attributes { %attr }, $content Emph Emphasized text, a list of inlines ("content"). Emph [ @inlines ] Image Image with alt text ("content", a list of inlines) and "target" (list of "url" and "title") with attributes ("attr", "id", "class", "classes", "keyvals"). Image attributes { %attr }, [ @inlines ], [ $url, $title ] Serializing the attributes in JSON can be disabled with "PANDOC_VERSION". LineBreak Hard line break LineBreak Link Hyperlink with link text ("content", a list of inlines) and "target" (list of "url" and "title") with attributes ("attr", "id", "class", "classes", "keyvals"). Link attributes { %attr }, [ @inlines ], [ $url, $title ] Serializing the attributes in JSON can be disabled with "PANDOC_VERSION". Math TeX math, given as literal string ("content") with "type" (one of "DisplayMath" and "InlineMath"). Math $type, $content Note Footnote or Endnote, a list of blocks ("content"). Note [ @blocks ] Quoted Quoted text with quote "type" (one of "SingleQuote" and "DoubleQuote") and a list of inlines ("content"). Quoted $type, [ @inlines ] RawInline Raw inline with "format" (a string) and "content" (a string). RawInline $format, $content SmallCaps Small caps text, a list of inlines ("content"). SmallCaps [ @inlines ] SoftBreak Soft line break SoftBreak Note that the "SoftBreak" element was added in Pandoc 1.16 to as a matter of editing convenience to preserve line breaks (as opposed to paragraph breaks) from input source to output. If you are going to feed a document containing "SoftBreak" elements to Pandoc < 1.16 you will have to set the package variable or environment variable "PANDOC_VERSION" to 1.15 or below. Space Inter-word space Space Span Generic container of inlines ("content") with attributes ("attr", "id", "class", "classes", "keyvals"). Span attributes { %attr }, [ @inlines ] Str Plain text, a string ("content"). Str $content Strikeout Strikeout text, a list of inlines ("content"). Strikeout [ @inlines ] Strong Strongly emphasized text, a list of inlines ("content"). Strong [ @inlines ] Subscript Subscripted text, a list of inlines ("content"). Supscript [ @inlines ] Superscript Superscripted text, a list of inlines ("content"). Superscript [ @inlines ] METADATA ELEMENTS Metadata can be provided in YAML syntax or via command line option "-M". All metadata elements return true for "is_meta". Metadata elements can be converted to unblessed Perl array references, hash references, and scalars with method "metavalue". On the document level, metadata (document method "meta") is a hash reference with values being metadata elements. Document method "metavalue" returns a flattened copy of this hash. MetaString A plain text string metadata value ("content"). MetaString $content MetaString values can also be set via pandoc command line client: pandoc -M key=$content MetaBool A Boolean metadata value ("content"). The special values "false" and "FALSE" are recognized as false in addition to normal false values (0, "undef", ""...). MetaBool $content MetaBool values can also be set via pandoc command line client: pandoc -M key=true pandoc -M key=false MetaInlines Container for a list of inlines ("content") in metadata. MetaInlines [ @inlines ] MetaBlocks Container for a list of blocks ("content") in metadata. MetaInlines [ @blocks ] MetaList A list of other metadata elements ("content"). MetaList [ @values ] MetaMap A map of keys to other metadata elements. MetaMap { %map } DOCUMENT ELEMENT Document Root element, consisting of metadata hash ("meta") and document element array ("content"). Document $meta, [ @blocks ] Document "metavalue" returns a copy of the metadata hash with all metadata elements flattened to unblessed values: $doc->metavalue # equivalent to { map { $_ => $doc->meta->{$_}->metavalue } keys %{$doc->meta} } TYPE KEYWORDS The following document elements are only as used as type keywords in other document elements: * "SingleQuote", "DoubleQuote" * "DisplayMath", "InlineMath" * "AuthorInText", "SuppressAuthor", "NormalCitation" * "AlignLeft", "AlignRight", "AlignCenter", "AlignDefault" * "DefaultStyle", "Example", "Decimal", "LowerRoman", "UpperRoman", "LowerAlpha", "UpperAlpha" * "DefaultDelim", "Period", "OneParen", "TwoParens" SEE ALSO Pandoc implements a wrapper around the pandoc executable. Text.Pandoc.Definition contains the original definition of Pandoc document data structure in Haskell. This module version was last aligned with pandoc-types-1.16.1. AUTHOR Jakob Voß CONTRIBUTORS Benct Philip Jonsson COPYRIGHT AND LICENSE Copyright 2014- Jakob Voß GNU General Public License, Version 2 This module is heavily based on Pandoc by John MacFarlane.