present - ActiveState ActiveGo 1.8
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Package present

import "golang.org/x/tools/present"
Overview
Index
Examples

Overview ▾

The present file format

Present files have the following format. The first non-blank non-comment line is the title, so the header looks like

Title of document
Subtitle of document
15:04 2 Jan 2006
Tags: foo, bar, baz
<blank line>
Author Name
Job title, Company
joe@example.com
http://url/
@twitter_name

The subtitle, date, and tags lines are optional.

The date line may be written without a time:

2 Jan 2006

In this case, the time will be interpreted as 10am UTC on that date.

The tags line is a comma-separated list of tags that may be used to categorize the document.

The author section may contain a mixture of text, twitter names, and links. For slide presentations, only the plain text lines will be displayed on the first slide.

Multiple presenters may be specified, separated by a blank line.

After that come slides/sections, each after a blank line:

* Title of slide or section (must have asterisk)

Some Text

** Subsection

- bullets
- more bullets
- a bullet with

*** Sub-subsection

Some More text

  Preformatted text
  is indented (however you like)

Further Text, including invocations like:

.code x.go /^func main/,/^}/
.play y.go
.image image.jpg
.background image.jpg
.iframe http://foo
.link http://foo label
.html file.html
.caption _Gopher_ by [[http://www.reneefrench.com][Renée French]]

Again, more text

Blank lines are OK (not mandatory) after the title and after the text. Text, bullets, and .code etc. are all optional; title is not.

Lines starting with # in column 1 are commentary.

Fonts:

Within the input for plain text or lists, text bracketed by font markers will be presented in italic, bold, or program font. Marker characters are _ (italic), * (bold) and ` (program font). An opening marker must be preceded by a space or punctuation character or else be at start of a line; similarly, a closing marker must be followed by a space or punctuation character or else be at the end of a line. Unmatched markers appear as plain text. There must be no spaces between markers. Within marked text, a single marker character becomes a space and a doubled single marker quotes the marker character.

at the beginning of a line or else be preceded by a space or punctuation; similarly a closing marker must be at the end of the lineo

_italic_
*bold*
`program`
Markup—_especially_italic_text_—can easily be overused.
_Why_use_scoped__ptr_? Use plain ***ptr* instead.

Inline links:

Links can be included in any text with the form [[url][label]], or [[url]] to use the URL itself as the label.

Functions:

A number of template functions are available through invocations in the input text. Each such invocation contains a period as the first character on the line, followed immediately by the name of the function, followed by any arguments. A typical invocation might be

.play demo.go /^func show/,/^}/

(except that the ".play" must be at the beginning of the line and not be indented like this.)

Here follows a description of the functions:

code:

Injects program source into the output by extracting code from files and injecting them as HTML-escaped <pre> blocks. The argument is a file name followed by an optional address that specifies what section of the file to display. The address syntax is similar in its simplest form to that of ed, but comes from sam and is more general. See

http://plan9.bell-labs.com/sys/doc/sam/sam.html Table II

for full details. The displayed block is always rounded out to a full line at both ends.

If no pattern is present, the entire file is displayed.

Any line in the program that ends with the four characters

OMIT

is deleted from the source before inclusion, making it easy to write things like

.code test.go /START OMIT/,/END OMIT/

to find snippets like this

tedious_code = boring_function()
// START OMIT
interesting_code = fascinating_function()
// END OMIT

and see only this:

interesting_code = fascinating_function()

Also, inside the displayed text a line that ends

// HL

will be highlighted in the display; the 'h' key in the browser will toggle extra emphasis of any highlighted lines. A highlighting mark may have a suffix word, such as

// HLxxx

Such highlights are enabled only if the code invocation ends with "HL" followed by the word:

.code test.go /^type Foo/,/^}/ HLxxx

The .code function may take one or more flags immediately preceding the filename. This command shows test.go in an editable text area:

.code -edit test.go

This command shows test.go with line numbers:

.code -numbers test.go

play:

The function "play" is the same as "code" but puts a button on the displayed source so the program can be run from the browser. Although only the selected text is shown, all the source is included in the HTML output so it can be presented to the compiler.

link:

Create a hyperlink. The syntax is 1 or 2 space-separated arguments. The first argument is always the HTTP URL. If there is a second argument, it is the text label to display for this link.

.link http://golang.org golang.org

image:

The template uses the function "image" to inject picture files.

The syntax is simple: 1 or 3 space-separated arguments. The first argument is always the file name. If there are more arguments, they are the height and width; both must be present, or substituted with an underscore. Replacing a dimension argument with the underscore parameter preserves the aspect ratio of the image when scaling.

.image images/betsy.jpg 100 200

.image images/janet.jpg _ 300

video:

The template uses the function "video" to inject video files.

The syntax is simple: 2 or 4 space-separated arguments. The first argument is always the file name. The second argument is always the file content-type. If there are more arguments, they are the height and width; both must be present, or substituted with an underscore. Replacing a dimension argument with the underscore parameter preserves the aspect ratio of the video when scaling.

.video videos/evangeline.mp4 video/mp4 400 600

.video videos/mabel.ogg video/ogg 500 _

background:

The template uses the function "background" to set the background image for a slide. The only argument is the file name of the image.

.background images/susan.jpg

caption:

The template uses the function "caption" to inject figure captions.

The text after ".caption" is embedded in a figcaption element after processing styling and links as in standard text lines.

.caption _Gopher_ by [[http://www.reneefrench.com][Renée French]]

iframe:

The function "iframe" injects iframes (pages inside pages). Its syntax is the same as that of image.

html:

The function html includes the contents of the specified file as unescaped HTML. This is useful for including custom HTML elements that cannot be created using only the slide format. It is your responsibilty to make sure the included HTML is valid and safe.

.html file.html

Presenter notes:

Presenter notes may be enabled by appending the "-notes" flag when you run your "present" binary.

This will allow you to open a second window by pressing 'N' from your browser displaying your slides. The second window is completely synced with your main window, except that presenter notes are only visible on the second window.

Lines that begin with ": " are treated as presenter notes.

* Title of slide

Some Text

: Presenter notes (first paragraph)
: Presenter notes (subsequent paragraph(s))

Notes may appear anywhere within the slide text. For example:

* Title of slide

: Presenter notes (first paragraph)

Some Text

: Presenter notes (subsequent paragraph(s))

This has the same result as the example above.

Variables

NotesEnabled specifies whether presenter notes should be displayed in the present user interface.

var NotesEnabled = false

PlayEnabled specifies whether runnable playground snippets should be displayed in the present user interface.

var PlayEnabled = false

func Register

func Register(name string, parser ParseFunc)

Register binds the named action, which does not begin with a period, to the specified parser to be invoked when the name, with a period, appears in the present input text.

func Style

func Style(s string) template.HTML

Style returns s with HTML entities escaped and font indicators turned into HTML font tags.

Example

Code:

const s = "*Gophers* are _clearly_ > *cats*!"
fmt.Println(Style(s))

Output:

<b>Gophers</b> are <i>clearly</i> &gt; <b>cats</b>!

func Template

func Template() *template.Template

Template returns an empty template with the action functions in its FuncMap.

type Author

Author represents the person who wrote and/or is presenting the document.

type Author struct {
    Elem []Elem
}

func (*Author) TextElem

func (p *Author) TextElem() (elems []Elem)

TextElem returns the first text elements of the author details. This is used to display the author' name, job title, and company without the contact details.

type Background

type Background struct {
    URL string
}

func (Background) TemplateName

func (i Background) TemplateName() string

type Caption

type Caption struct {
    Text string
}

func (Caption) TemplateName

func (c Caption) TemplateName() string

type Code

type Code struct {
    Text     template.HTML
    Play     bool   // runnable code
    Edit     bool   // editable code
    FileName string // file name
    Ext      string // file extension
    Raw      []byte // content of the file
}

func (Code) TemplateName

func (c Code) TemplateName() string

type Context

A Context specifies the supporting context for parsing a presentation.

type Context struct {
    // ReadFile reads the file named by filename and returns the contents.
    ReadFile func(filename string) ([]byte, error)
}

func (*Context) Parse

func (ctx *Context) Parse(r io.Reader, name string, mode ParseMode) (*Doc, error)

Parse parses a document from r.

type Doc

Doc represents an entire document.

type Doc struct {
    Title      string
    Subtitle   string
    Time       time.Time
    Authors    []Author
    TitleNotes []string
    Sections   []Section
    Tags       []string
}

func Parse

func Parse(r io.Reader, name string, mode ParseMode) (*Doc, error)

Parse parses a document from r. Parse reads assets used by the presentation from the file system using ioutil.ReadFile.

func (*Doc) Render

func (d *Doc) Render(w io.Writer, t *template.Template) error

Render renders the doc to the given writer using the provided template.

type Elem

Elem defines the interface for a present element. That is, something that can provide the name of the template used to render the element.

type Elem interface {
    TemplateName() string
}

type HTML

type HTML struct {
    template.HTML
}

func (HTML) TemplateName

func (s HTML) TemplateName() string

type Iframe

type Iframe struct {
    URL    string
    Width  int
    Height int
}

func (Iframe) TemplateName

func (i Iframe) TemplateName() string

type Image

type Image struct {
    URL    string
    Width  int
    Height int
}

func (Image) TemplateName

func (i Image) TemplateName() string

type Lines

Lines is a helper for parsing line-based input.

type Lines struct {
    // contains filtered or unexported fields
}
type Link struct {
    URL   *url.URL
    Label string
}

func (Link) TemplateName

func (l Link) TemplateName() string

type List

List represents a bulleted list.

type List struct {
    Bullet []string
}

func (List) TemplateName

func (l List) TemplateName() string

type ParseFunc

type ParseFunc func(ctx *Context, fileName string, lineNumber int, inputLine string) (Elem, error)

type ParseMode

ParseMode represents flags for the Parse function.

type ParseMode int
const (
    // If set, parse only the title and subtitle.
    TitlesOnly ParseMode = 1
)

type Section

Section represents a section of a document (such as a presentation slide) comprising a title and a list of elements.

type Section struct {
    Number []int
    Title  string
    Elem   []Elem
    Notes  []string
}

func (Section) FormattedNumber

func (s Section) FormattedNumber() string

FormattedNumber returns a string containing the concatenation of the numbers identifying a Section.

func (Section) Level

func (s Section) Level() int

Level returns the level of the given section. The document title is level 1, main section 2, etc.

func (*Section) Render

func (s *Section) Render(w io.Writer, t *template.Template) error

Render renders the section to the given writer using the provided template.

func (Section) Sections

func (s Section) Sections() (sections []Section)

func (Section) TemplateName

func (s Section) TemplateName() string

type Text

Text represents an optionally preformatted paragraph.

type Text struct {
    Lines []string
    Pre   bool
}

func (Text) TemplateName

func (t Text) TemplateName() string

type Video

type Video struct {
    URL        string
    SourceType string
    Width      int
    Height     int
}

func (Video) TemplateName

func (v Video) TemplateName() string