blackfriday: github.com/russross/blackfriday Index | Files

package blackfriday

import "github.com/russross/blackfriday"

Package blackfriday is a Markdown processor.

It translates plain text with simple formatting rules into HTML or LaTeX.

Sanitized Anchor Names

Blackfriday includes an algorithm for creating sanitized anchor names corresponding to a given input text. This algorithm is used to create anchors for headings when EXTENSION_AUTO_HEADER_IDS is enabled. The algorithm is specified below, so that other packages can create compatible anchor names and links to those anchors.

The algorithm iterates over the input text, interpreted as UTF-8, one Unicode code point (rune) at a time. All runes that are letters (category L) or numbers (category N) are considered valid characters. They are mapped to lower case, and included in the output. All other runes are considered invalid characters. Invalid characters that preceed the first valid character, as well as invalid character that follow the last valid character are dropped completely. All other sequences of invalid characters between two valid characters are replaced with a single dash character '-'.

SanitizedAnchorName exposes this functionality, and can be used to create compatible links to the anchor names generated by blackfriday. This algorithm is also implemented in a small standalone package at github.com/shurcooL/sanitized_anchor_name. It can be useful for clients that want a small package and don't need full functionality of blackfriday.

Index

Package Files

block.go doc.go html.go inline.go latex.go markdown.go smartypants.go

Constants

const (
    HTML_SKIP_HTML                 = 1 << iota // skip preformatted HTML blocks
    HTML_SKIP_STYLE                            // skip embedded <style> elements
    HTML_SKIP_IMAGES                           // skip embedded images
    HTML_SKIP_LINKS                            // skip all links
    HTML_SAFELINK                              // only link to trusted protocols
    HTML_NOFOLLOW_LINKS                        // only link with rel="nofollow"
    HTML_NOREFERRER_LINKS                      // only link with rel="noreferrer"
    HTML_HREF_TARGET_BLANK                     // add a blank target
    HTML_TOC                                   // generate a table of contents
    HTML_OMIT_CONTENTS                         // skip the main contents (for a standalone table of contents)
    HTML_COMPLETE_PAGE                         // generate a complete HTML page
    HTML_USE_XHTML                             // generate XHTML output instead of HTML
    HTML_USE_SMARTYPANTS                       // enable smart punctuation substitutions
    HTML_SMARTYPANTS_FRACTIONS                 // enable smart fractions (with HTML_USE_SMARTYPANTS)
    HTML_SMARTYPANTS_DASHES                    // enable smart dashes (with HTML_USE_SMARTYPANTS)
    HTML_SMARTYPANTS_LATEX_DASHES              // enable LaTeX-style dashes (with HTML_USE_SMARTYPANTS and HTML_SMARTYPANTS_DASHES)
    HTML_SMARTYPANTS_ANGLED_QUOTES             // enable angled double quotes (with HTML_USE_SMARTYPANTS) for double quotes rendering
    HTML_SMARTYPANTS_QUOTES_NBSP               // enable "French guillemets" (with HTML_USE_SMARTYPANTS)
    HTML_FOOTNOTE_RETURN_LINKS                 // generate a link at the end of a footnote to return to the source
)

Html renderer configuration options.

const (
    EXTENSION_NO_INTRA_EMPHASIS          = 1 << iota // ignore emphasis markers inside words
    EXTENSION_TABLES                                 // render tables
    EXTENSION_FENCED_CODE                            // render fenced code blocks
    EXTENSION_AUTOLINK                               // detect embedded URLs that are not explicitly marked
    EXTENSION_STRIKETHROUGH                          // strikethrough text using ~~test~~
    EXTENSION_LAX_HTML_BLOCKS                        // loosen up HTML block parsing rules
    EXTENSION_SPACE_HEADERS                          // be strict about prefix header rules
    EXTENSION_HARD_LINE_BREAK                        // translate newlines into line breaks
    EXTENSION_TAB_SIZE_EIGHT                         // expand tabs to eight spaces instead of four
    EXTENSION_FOOTNOTES                              // Pandoc-style footnotes
    EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK             // No need to insert an empty line to start a (code, quote, ordered list, unordered list) block
    EXTENSION_HEADER_IDS                             // specify header IDs  with {#id}
    EXTENSION_TITLEBLOCK                             // Titleblock ala pandoc
    EXTENSION_AUTO_HEADER_IDS                        // Create the header ID from the text
    EXTENSION_BACKSLASH_LINE_BREAK                   // translate trailing backslashes into line breaks
    EXTENSION_DEFINITION_LISTS                       // render definition lists
    EXTENSION_JOIN_LINES                             // delete newline and join lines

)

These are the supported markdown parsing extensions. OR these values together to select multiple extensions.

const (
    LINK_TYPE_NOT_AUTOLINK = iota
    LINK_TYPE_NORMAL
    LINK_TYPE_EMAIL
)

These are the possible flag values for the link renderer. Only a single one of these values will be used; they are not ORed together. These are mostly of interest if you are writing a new output format.

const (
    LIST_TYPE_ORDERED = 1 << iota
    LIST_TYPE_DEFINITION
    LIST_TYPE_TERM
    LIST_ITEM_CONTAINS_BLOCK
    LIST_ITEM_BEGINNING_OF_LIST
    LIST_ITEM_END_OF_LIST
)

These are the possible flag values for the ListItem renderer. Multiple flag values may be ORed together. These are mostly of interest if you are writing a new output format.

const (
    TABLE_ALIGNMENT_LEFT = 1 << iota
    TABLE_ALIGNMENT_RIGHT
    TABLE_ALIGNMENT_CENTER = (TABLE_ALIGNMENT_LEFT | TABLE_ALIGNMENT_RIGHT)
)

These are the possible flag values for the table cell renderer. Only a single one of these values will be used; they are not ORed together. These are mostly of interest if you are writing a new output format.

const (
    TAB_SIZE_DEFAULT = 4
    TAB_SIZE_EIGHT   = 8
)

The size of a tab stop.

const VERSION = "1.5"

func Markdown Uses

func Markdown(input []byte, renderer Renderer, extensions int) []byte

Markdown is the main rendering function. It parses and renders a block of markdown-encoded text. The supplied Renderer is used to format the output, and extensions dictates which non-standard extensions are enabled.

To use the supplied Html or LaTeX renderers, see HtmlRenderer and LatexRenderer, respectively.

func MarkdownBasic Uses

func MarkdownBasic(input []byte) []byte

MarkdownBasic is a convenience function for simple rendering. It processes markdown input with no extensions enabled.

func MarkdownCommon Uses

func MarkdownCommon(input []byte) []byte

Call Markdown with most useful extensions enabled MarkdownCommon is a convenience function for simple rendering. It processes markdown input with common extensions enabled, including:

* Smartypants processing with smart fractions and LaTeX dashes

* Intra-word emphasis suppression

* Tables

* Fenced code blocks

* Autolinking

* Strikethrough support

* Strict header parsing

* Custom Header IDs

func MarkdownOptions Uses

func MarkdownOptions(input []byte, renderer Renderer, opts Options) []byte

MarkdownOptions is just like Markdown but takes additional options through the Options struct.

func SanitizedAnchorName Uses

func SanitizedAnchorName(text string) string

SanitizedAnchorName returns a sanitized anchor name for the given text.

It implements the algorithm specified in the package comment.

type Html Uses

type Html struct {
    // contains filtered or unexported fields
}

Html is a type that implements the Renderer interface for HTML output.

Do not create this directly, instead use the HtmlRenderer function.

func (options *Html) AutoLink(out *bytes.Buffer, link []byte, kind int)

func (*Html) BlockCode Uses

func (options *Html) BlockCode(out *bytes.Buffer, text []byte, info string)

func (*Html) BlockHtml Uses

func (options *Html) BlockHtml(out *bytes.Buffer, text []byte)

func (*Html) BlockQuote Uses

func (options *Html) BlockQuote(out *bytes.Buffer, text []byte)

func (*Html) CodeSpan Uses

func (options *Html) CodeSpan(out *bytes.Buffer, text []byte)

func (*Html) DocumentFooter Uses

func (options *Html) DocumentFooter(out *bytes.Buffer)

func (*Html) DocumentHeader Uses

func (options *Html) DocumentHeader(out *bytes.Buffer)

func (*Html) DoubleEmphasis Uses

func (options *Html) DoubleEmphasis(out *bytes.Buffer, text []byte)

func (*Html) Emphasis Uses

func (options *Html) Emphasis(out *bytes.Buffer, text []byte)

func (*Html) Entity Uses

func (options *Html) Entity(out *bytes.Buffer, entity []byte)

func (*Html) FootnoteItem Uses

func (options *Html) FootnoteItem(out *bytes.Buffer, name, text []byte, flags int)

func (*Html) FootnoteRef Uses

func (options *Html) FootnoteRef(out *bytes.Buffer, ref []byte, id int)

func (*Html) Footnotes Uses

func (options *Html) Footnotes(out *bytes.Buffer, text func() bool)

func (*Html) GetFlags Uses

func (options *Html) GetFlags() int

func (*Html) HRule Uses

func (options *Html) HRule(out *bytes.Buffer)

func (*Html) Header Uses

func (options *Html) Header(out *bytes.Buffer, text func() bool, level int, id string)

func (*Html) Image Uses

func (options *Html) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte)

func (*Html) LineBreak Uses

func (options *Html) LineBreak(out *bytes.Buffer)
func (options *Html) Link(out *bytes.Buffer, link []byte, title []byte, content []byte)

func (*Html) List Uses

func (options *Html) List(out *bytes.Buffer, text func() bool, flags int)

func (*Html) ListItem Uses

func (options *Html) ListItem(out *bytes.Buffer, text []byte, flags int)

func (*Html) NormalText Uses

func (options *Html) NormalText(out *bytes.Buffer, text []byte)

func (*Html) Paragraph Uses

func (options *Html) Paragraph(out *bytes.Buffer, text func() bool)

func (*Html) RawHtmlTag Uses

func (options *Html) RawHtmlTag(out *bytes.Buffer, text []byte)

func (*Html) Smartypants Uses

func (options *Html) Smartypants(out *bytes.Buffer, text []byte)

func (*Html) StrikeThrough Uses

func (options *Html) StrikeThrough(out *bytes.Buffer, text []byte)

func (*Html) Table Uses

func (options *Html) Table(out *bytes.Buffer, header []byte, body []byte, columnData []int)

func (*Html) TableCell Uses

func (options *Html) TableCell(out *bytes.Buffer, text []byte, align int)

func (*Html) TableHeaderCell Uses

func (options *Html) TableHeaderCell(out *bytes.Buffer, text []byte, align int)

func (*Html) TableRow Uses

func (options *Html) TableRow(out *bytes.Buffer, text []byte)

func (*Html) TitleBlock Uses

func (options *Html) TitleBlock(out *bytes.Buffer, text []byte)

func (*Html) TocFinalize Uses

func (options *Html) TocFinalize()

func (*Html) TocHeader Uses

func (options *Html) TocHeader(text []byte, level int)

func (*Html) TocHeaderWithAnchor Uses

func (options *Html) TocHeaderWithAnchor(text []byte, level int, anchor string)

func (*Html) TripleEmphasis Uses

func (options *Html) TripleEmphasis(out *bytes.Buffer, text []byte)

type HtmlRendererParameters Uses

type HtmlRendererParameters struct {
    // Prepend this text to each relative URL.
    AbsolutePrefix string
    // Add this text to each footnote anchor, to ensure uniqueness.
    FootnoteAnchorPrefix string
    // Show this text inside the <a> tag for a footnote return link, if the
    // HTML_FOOTNOTE_RETURN_LINKS flag is enabled. If blank, the string
    // <sup>[return]</sup> is used.
    FootnoteReturnLinkContents string
    // If set, add this text to the front of each Header ID, to ensure
    // uniqueness.
    HeaderIDPrefix string
    // If set, add this text to the back of each Header ID, to ensure uniqueness.
    HeaderIDSuffix string
}

type Latex Uses

type Latex struct {
}

Latex is a type that implements the Renderer interface for LaTeX output.

Do not create this directly, instead use the LatexRenderer function.

func (options *Latex) AutoLink(out *bytes.Buffer, link []byte, kind int)

func (*Latex) BlockCode Uses

func (options *Latex) BlockCode(out *bytes.Buffer, text []byte, info string)

render code chunks using verbatim, or listings if we have a language

func (*Latex) BlockHtml Uses

func (options *Latex) BlockHtml(out *bytes.Buffer, text []byte)

func (*Latex) BlockQuote Uses

func (options *Latex) BlockQuote(out *bytes.Buffer, text []byte)

func (*Latex) CodeSpan Uses

func (options *Latex) CodeSpan(out *bytes.Buffer, text []byte)

func (*Latex) DocumentFooter Uses

func (options *Latex) DocumentFooter(out *bytes.Buffer)

func (*Latex) DocumentHeader Uses

func (options *Latex) DocumentHeader(out *bytes.Buffer)

header and footer

func (*Latex) DoubleEmphasis Uses

func (options *Latex) DoubleEmphasis(out *bytes.Buffer, text []byte)

func (*Latex) Emphasis Uses

func (options *Latex) Emphasis(out *bytes.Buffer, text []byte)

func (*Latex) Entity Uses

func (options *Latex) Entity(out *bytes.Buffer, entity []byte)

func (*Latex) FootnoteItem Uses

func (options *Latex) FootnoteItem(out *bytes.Buffer, name, text []byte, flags int)

func (*Latex) FootnoteRef Uses

func (options *Latex) FootnoteRef(out *bytes.Buffer, ref []byte, id int)

TODO: this

func (*Latex) Footnotes Uses

func (options *Latex) Footnotes(out *bytes.Buffer, text func() bool)

TODO: this

func (*Latex) GetFlags Uses

func (options *Latex) GetFlags() int

func (*Latex) HRule Uses

func (options *Latex) HRule(out *bytes.Buffer)

func (*Latex) Header Uses

func (options *Latex) Header(out *bytes.Buffer, text func() bool, level int, id string)

func (*Latex) Image Uses

func (options *Latex) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte)

func (*Latex) LineBreak Uses

func (options *Latex) LineBreak(out *bytes.Buffer)
func (options *Latex) Link(out *bytes.Buffer, link []byte, title []byte, content []byte)

func (*Latex) List Uses

func (options *Latex) List(out *bytes.Buffer, text func() bool, flags int)

func (*Latex) ListItem Uses

func (options *Latex) ListItem(out *bytes.Buffer, text []byte, flags int)

func (*Latex) NormalText Uses

func (options *Latex) NormalText(out *bytes.Buffer, text []byte)

func (*Latex) Paragraph Uses

func (options *Latex) Paragraph(out *bytes.Buffer, text func() bool)

func (*Latex) RawHtmlTag Uses

func (options *Latex) RawHtmlTag(out *bytes.Buffer, tag []byte)

func (*Latex) StrikeThrough Uses

func (options *Latex) StrikeThrough(out *bytes.Buffer, text []byte)

func (*Latex) Table Uses

func (options *Latex) Table(out *bytes.Buffer, header []byte, body []byte, columnData []int)

func (*Latex) TableCell Uses

func (options *Latex) TableCell(out *bytes.Buffer, text []byte, align int)

func (*Latex) TableHeaderCell Uses

func (options *Latex) TableHeaderCell(out *bytes.Buffer, text []byte, align int)

func (*Latex) TableRow Uses

func (options *Latex) TableRow(out *bytes.Buffer, text []byte)

func (*Latex) TitleBlock Uses

func (options *Latex) TitleBlock(out *bytes.Buffer, text []byte)

func (*Latex) TripleEmphasis Uses

func (options *Latex) TripleEmphasis(out *bytes.Buffer, text []byte)

type Options Uses

type Options struct {
    // Extensions is a flag set of bit-wise ORed extension bits. See the
    // EXTENSION_* flags defined in this package.
    Extensions int

    // ReferenceOverride is an optional function callback that is called every
    // time a reference is resolved.
    //
    // In Markdown, the link reference syntax can be made to resolve a link to
    // a reference instead of an inline URL, in one of the following ways:
    //
    //  * [link text][refid]
    //  * [refid][]
    //
    // Usually, the refid is defined at the bottom of the Markdown document. If
    // this override function is provided, the refid is passed to the override
    // function first, before consulting the defined refids at the bottom. If
    // the override function indicates an override did not occur, the refids at
    // the bottom will be used to fill in the link details.
    ReferenceOverride ReferenceOverrideFunc
}

Options represents configurable overrides and callbacks (in addition to the extension flag set) for configuring a Markdown parse.

type Reference Uses

type Reference struct {
    // Link is usually the URL the reference points to.
    Link string
    // Title is the alternate text describing the link in more detail.
    Title string
    // Text is the optional text to override the ref with if the syntax used was
    // [refid][]
    Text string
}

Reference represents the details of a link. See the documentation in Options for more details on use-case.

type ReferenceOverrideFunc Uses

type ReferenceOverrideFunc func(reference string) (ref *Reference, overridden bool)

ReferenceOverrideFunc is expected to be called with a reference string and return either a valid Reference type that the reference string maps to or nil. If overridden is false, the default reference logic will be executed. See the documentation in Options for more details on use-case.

type Renderer Uses

type Renderer interface {
    // block-level callbacks
    BlockCode(out *bytes.Buffer, text []byte, infoString string)
    BlockQuote(out *bytes.Buffer, text []byte)
    BlockHtml(out *bytes.Buffer, text []byte)
    Header(out *bytes.Buffer, text func() bool, level int, id string)
    HRule(out *bytes.Buffer)
    List(out *bytes.Buffer, text func() bool, flags int)
    ListItem(out *bytes.Buffer, text []byte, flags int)
    Paragraph(out *bytes.Buffer, text func() bool)
    Table(out *bytes.Buffer, header []byte, body []byte, columnData []int)
    TableRow(out *bytes.Buffer, text []byte)
    TableHeaderCell(out *bytes.Buffer, text []byte, flags int)
    TableCell(out *bytes.Buffer, text []byte, flags int)
    Footnotes(out *bytes.Buffer, text func() bool)
    FootnoteItem(out *bytes.Buffer, name, text []byte, flags int)
    TitleBlock(out *bytes.Buffer, text []byte)

    // Span-level callbacks
    AutoLink(out *bytes.Buffer, link []byte, kind int)
    CodeSpan(out *bytes.Buffer, text []byte)
    DoubleEmphasis(out *bytes.Buffer, text []byte)
    Emphasis(out *bytes.Buffer, text []byte)
    Image(out *bytes.Buffer, link []byte, title []byte, alt []byte)
    LineBreak(out *bytes.Buffer)
    Link(out *bytes.Buffer, link []byte, title []byte, content []byte)
    RawHtmlTag(out *bytes.Buffer, tag []byte)
    TripleEmphasis(out *bytes.Buffer, text []byte)
    StrikeThrough(out *bytes.Buffer, text []byte)
    FootnoteRef(out *bytes.Buffer, ref []byte, id int)

    // Low-level callbacks
    Entity(out *bytes.Buffer, entity []byte)
    NormalText(out *bytes.Buffer, text []byte)

    // Header and footer
    DocumentHeader(out *bytes.Buffer)
    DocumentFooter(out *bytes.Buffer)

    GetFlags() int
}

Renderer is the rendering interface. This is mostly of interest if you are implementing a new rendering format.

When a byte slice is provided, it contains the (rendered) contents of the element.

When a callback is provided instead, it will write the contents of the respective element directly to the output buffer and return true on success. If the callback returns false, the rendering function should reset the output buffer as though it had never been called.

Currently Html and Latex implementations are provided

func HtmlRenderer Uses

func HtmlRenderer(flags int, title string, css string) Renderer

HtmlRenderer creates and configures an Html object, which satisfies the Renderer interface.

flags is a set of HTML_* options ORed together. title is the title of the document, and css is a URL for the document's stylesheet. title and css are only used when HTML_COMPLETE_PAGE is selected.

func HtmlRendererWithParameters Uses

func HtmlRendererWithParameters(flags int, title string,
    css string, renderParameters HtmlRendererParameters) Renderer

func LatexRenderer Uses

func LatexRenderer(flags int) Renderer

LatexRenderer creates and configures a Latex object, which satisfies the Renderer interface.

flags is a set of LATEX_* options ORed together (currently no such options are defined).

Package blackfriday imports 7 packages (graph) and is imported by 2169 packages. Updated 2019-05-20. Refresh now. Tools for package owners.