| 1 | // Copyright 2011 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package present |
| 6 | |
| 7 | import ( |
| 8 | "bufio" |
| 9 | "bytes" |
| 10 | "errors" |
| 11 | "fmt" |
| 12 | "html/template" |
| 13 | "io" |
| 14 | "io/ioutil" |
| 15 | "log" |
| 16 | "net/url" |
| 17 | "regexp" |
| 18 | "strings" |
| 19 | "time" |
| 20 | "unicode" |
| 21 | "unicode/utf8" |
| 22 | |
| 23 | "github.com/yuin/goldmark" |
| 24 | "github.com/yuin/goldmark/ast" |
| 25 | "github.com/yuin/goldmark/renderer/html" |
| 26 | "github.com/yuin/goldmark/text" |
| 27 | ) |
| 28 | |
| 29 | var ( |
| 30 | parsers = make(map[string]ParseFunc) |
| 31 | funcs = template.FuncMap{} |
| 32 | ) |
| 33 | |
| 34 | // Template returns an empty template with the action functions in its FuncMap. |
| 35 | func Template() *template.Template { |
| 36 | return template.New("").Funcs(funcs) |
| 37 | } |
| 38 | |
| 39 | // Render renders the doc to the given writer using the provided template. |
| 40 | func (d *Doc) Render(w io.Writer, t *template.Template) error { |
| 41 | data := struct { |
| 42 | *Doc |
| 43 | Template *template.Template |
| 44 | PlayEnabled bool |
| 45 | NotesEnabled bool |
| 46 | }{d, t, PlayEnabled, NotesEnabled} |
| 47 | return t.ExecuteTemplate(w, "root", data) |
| 48 | } |
| 49 | |
| 50 | // Render renders the section to the given writer using the provided template. |
| 51 | func (s *Section) Render(w io.Writer, t *template.Template) error { |
| 52 | data := struct { |
| 53 | *Section |
| 54 | Template *template.Template |
| 55 | PlayEnabled bool |
| 56 | }{s, t, PlayEnabled} |
| 57 | return t.ExecuteTemplate(w, "section", data) |
| 58 | } |
| 59 | |
| 60 | type ParseFunc func(ctx *Context, fileName string, lineNumber int, inputLine string) (Elem, error) |
| 61 | |
| 62 | // Register binds the named action, which does not begin with a period, to the |
| 63 | // specified parser to be invoked when the name, with a period, appears in the |
| 64 | // present input text. |
| 65 | func Register(name string, parser ParseFunc) { |
| 66 | if len(name) == 0 || name[0] == ';' { |
| 67 | panic("bad name in Register: " + name) |
| 68 | } |
| 69 | parsers["."+name] = parser |
| 70 | } |
| 71 | |
| 72 | // Doc represents an entire document. |
| 73 | type Doc struct { |
| 74 | Title string |
| 75 | Subtitle string |
| 76 | Summary string |
| 77 | Time time.Time |
| 78 | Authors []Author |
| 79 | TitleNotes []string |
| 80 | Sections []Section |
| 81 | Tags []string |
| 82 | OldURL []string |
| 83 | } |
| 84 | |
| 85 | // Author represents the person who wrote and/or is presenting the document. |
| 86 | type Author struct { |
| 87 | Elem []Elem |
| 88 | } |
| 89 | |
| 90 | // TextElem returns the first text elements of the author details. |
| 91 | // This is used to display the author' name, job title, and company |
| 92 | // without the contact details. |
| 93 | func (p *Author) TextElem() (elems []Elem) { |
| 94 | for _, el := range p.Elem { |
| 95 | if _, ok := el.(Text); !ok { |
| 96 | break |
| 97 | } |
| 98 | elems = append(elems, el) |
| 99 | } |
| 100 | return |
| 101 | } |
| 102 | |
| 103 | // Section represents a section of a document (such as a presentation slide) |
| 104 | // comprising a title and a list of elements. |
| 105 | type Section struct { |
| 106 | Number []int |
| 107 | Title string |
| 108 | ID string // HTML anchor ID |
| 109 | Elem []Elem |
| 110 | Notes []string |
| 111 | Classes []string |
| 112 | Styles []string |
| 113 | } |
| 114 | |
| 115 | // HTMLAttributes for the section |
| 116 | func (s Section) HTMLAttributes() template.HTMLAttr { |
| 117 | if len(s.Classes) == 0 && len(s.Styles) == 0 { |
| 118 | return "" |
| 119 | } |
| 120 | |
| 121 | var class string |
| 122 | if len(s.Classes) > 0 { |
| 123 | class = fmt.Sprintf(`class=%q`, strings.Join(s.Classes, " ")) |
| 124 | } |
| 125 | var style string |
| 126 | if len(s.Styles) > 0 { |
| 127 | style = fmt.Sprintf(`style=%q`, strings.Join(s.Styles, " ")) |
| 128 | } |
| 129 | return template.HTMLAttr(strings.Join([]string{class, style}, " ")) |
| 130 | } |
| 131 | |
| 132 | // Sections contained within the section. |
| 133 | func (s Section) Sections() (sections []Section) { |
| 134 | for _, e := range s.Elem { |
| 135 | if section, ok := e.(Section); ok { |
| 136 | sections = append(sections, section) |
| 137 | } |
| 138 | } |
| 139 | return |
| 140 | } |
| 141 | |
| 142 | // Level returns the level of the given section. |
| 143 | // The document title is level 1, main section 2, etc. |
| 144 | func (s Section) Level() int { |
| 145 | return len(s.Number) + 1 |
| 146 | } |
| 147 | |
| 148 | // FormattedNumber returns a string containing the concatenation of the |
| 149 | // numbers identifying a Section. |
| 150 | func (s Section) FormattedNumber() string { |
| 151 | b := &bytes.Buffer{} |
| 152 | for _, n := range s.Number { |
| 153 | fmt.Fprintf(b, "%v.", n) |
| 154 | } |
| 155 | return b.String() |
| 156 | } |
| 157 | |
| 158 | func (s Section) TemplateName() string { return "section" } |
| 159 | |
| 160 | // Elem defines the interface for a present element. That is, something that |
| 161 | // can provide the name of the template used to render the element. |
| 162 | type Elem interface { |
| 163 | TemplateName() string |
| 164 | } |
| 165 | |
| 166 | // renderElem implements the elem template function, used to render |
| 167 | // sub-templates. |
| 168 | func renderElem(t *template.Template, e Elem) (template.HTML, error) { |
| 169 | var data interface{} = e |
| 170 | if s, ok := e.(Section); ok { |
| 171 | data = struct { |
| 172 | Section |
| 173 | Template *template.Template |
| 174 | }{s, t} |
| 175 | } |
| 176 | return execTemplate(t, e.TemplateName(), data) |
| 177 | } |
| 178 | |
| 179 | // pageNum derives a page number from a section. |
| 180 | func pageNum(s Section, offset int) int { |
| 181 | if len(s.Number) == 0 { |
| 182 | return offset |
| 183 | } |
| 184 | return s.Number[0] + offset |
| 185 | } |
| 186 | |
| 187 | func init() { |
| 188 | funcs["elem"] = renderElem |
| 189 | funcs["pagenum"] = pageNum |
| 190 | } |
| 191 | |
| 192 | // execTemplate is a helper to execute a template and return the output as a |
| 193 | // template.HTML value. |
| 194 | func execTemplate(t *template.Template, name string, data interface{}) (template.HTML, error) { |
| 195 | b := new(bytes.Buffer) |
| 196 | err := t.ExecuteTemplate(b, name, data) |
| 197 | if err != nil { |
| 198 | return "", err |
| 199 | } |
| 200 | return template.HTML(b.String()), nil |
| 201 | } |
| 202 | |
| 203 | // Text represents an optionally preformatted paragraph. |
| 204 | type Text struct { |
| 205 | Lines []string |
| 206 | Pre bool |
| 207 | Raw string // original text, for Pre==true |
| 208 | } |
| 209 | |
| 210 | func (t Text) TemplateName() string { return "text" } |
| 211 | |
| 212 | // List represents a bulleted list. |
| 213 | type List struct { |
| 214 | Bullet []string |
| 215 | } |
| 216 | |
| 217 | func (l List) TemplateName() string { return "list" } |
| 218 | |
| 219 | // Lines is a helper for parsing line-based input. |
| 220 | type Lines struct { |
| 221 | line int // 0 indexed, so has 1-indexed number of last line returned |
| 222 | text []string |
| 223 | comment string |
| 224 | } |
| 225 | |
| 226 | func readLines(r io.Reader) (*Lines, error) { |
| 227 | var lines []string |
| 228 | s := bufio.NewScanner(r) |
| 229 | for s.Scan() { |
| 230 | lines = append(lines, s.Text()) |
| 231 | } |
| 232 | if err := s.Err(); err != nil { |
| 233 | return nil, err |
| 234 | } |
| 235 | return &Lines{0, lines, "#"}, nil |
| 236 | } |
| 237 | |
| 238 | func (l *Lines) next() (text string, ok bool) { |
| 239 | for { |
| 240 | current := l.line |
| 241 | l.line++ |
| 242 | if current >= len(l.text) { |
| 243 | return "", false |
| 244 | } |
| 245 | text = l.text[current] |
| 246 | // Lines starting with l.comment are comments. |
| 247 | if l.comment == "" || !strings.HasPrefix(text, l.comment) { |
| 248 | ok = true |
| 249 | break |
| 250 | } |
| 251 | } |
| 252 | return |
| 253 | } |
| 254 | |
| 255 | func (l *Lines) back() { |
| 256 | l.line-- |
| 257 | } |
| 258 | |
| 259 | func (l *Lines) nextNonEmpty() (text string, ok bool) { |
| 260 | for { |
| 261 | text, ok = l.next() |
| 262 | if !ok { |
| 263 | return |
| 264 | } |
| 265 | if len(text) > 0 { |
| 266 | break |
| 267 | } |
| 268 | } |
| 269 | return |
| 270 | } |
| 271 | |
| 272 | // A Context specifies the supporting context for parsing a presentation. |
| 273 | type Context struct { |
| 274 | // ReadFile reads the file named by filename and returns the contents. |
| 275 | ReadFile func(filename string) ([]byte, error) |
| 276 | } |
| 277 | |
| 278 | // ParseMode represents flags for the Parse function. |
| 279 | type ParseMode int |
| 280 | |
| 281 | const ( |
| 282 | // If set, parse only the title and subtitle. |
| 283 | TitlesOnly ParseMode = 1 |
| 284 | ) |
| 285 | |
| 286 | // Parse parses a document from r. |
| 287 | func (ctx *Context) Parse(r io.Reader, name string, mode ParseMode) (*Doc, error) { |
| 288 | doc := new(Doc) |
| 289 | lines, err := readLines(r) |
| 290 | if err != nil { |
| 291 | return nil, err |
| 292 | } |
| 293 | |
| 294 | // Detect Markdown-enabled vs legacy present file. |
| 295 | // Markdown-enabled files have a title line beginning with "# " |
| 296 | // (like preprocessed C files of yore). |
| 297 | isMarkdown := false |
| 298 | for i := lines.line; i < len(lines.text); i++ { |
| 299 | line := lines.text[i] |
| 300 | if line == "" { |
| 301 | continue |
| 302 | } |
| 303 | isMarkdown = strings.HasPrefix(line, "# ") |
| 304 | break |
| 305 | } |
| 306 | |
| 307 | sectionPrefix := "*" |
| 308 | if isMarkdown { |
| 309 | sectionPrefix = "##" |
| 310 | lines.comment = "//" |
| 311 | } |
| 312 | |
| 313 | for i := lines.line; i < len(lines.text); i++ { |
| 314 | if strings.HasPrefix(lines.text[i], sectionPrefix) { |
| 315 | break |
| 316 | } |
| 317 | |
| 318 | if isSpeakerNote(lines.text[i]) { |
| 319 | doc.TitleNotes = append(doc.TitleNotes, trimSpeakerNote(lines.text[i])) |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | err = parseHeader(doc, isMarkdown, lines) |
| 324 | if err != nil { |
| 325 | return nil, err |
| 326 | } |
| 327 | if mode&TitlesOnly != 0 { |
| 328 | return doc, nil |
| 329 | } |
| 330 | |
| 331 | // Authors |
| 332 | if doc.Authors, err = parseAuthors(name, sectionPrefix, lines); err != nil { |
| 333 | return nil, err |
| 334 | } |
| 335 | |
| 336 | // Sections |
| 337 | if doc.Sections, err = parseSections(ctx, name, sectionPrefix, lines, []int{}); err != nil { |
| 338 | return nil, err |
| 339 | } |
| 340 | |
| 341 | return doc, nil |
| 342 | } |
| 343 | |
| 344 | // Parse parses a document from r. Parse reads assets used by the presentation |
| 345 | // from the file system using ioutil.ReadFile. |
| 346 | func Parse(r io.Reader, name string, mode ParseMode) (*Doc, error) { |
| 347 | ctx := Context{ReadFile: ioutil.ReadFile} |
| 348 | return ctx.Parse(r, name, mode) |
| 349 | } |
| 350 | |
| 351 | // isHeading matches any section heading. |
| 352 | var ( |
| 353 | isHeadingLegacy = regexp.MustCompile(`^\*+( |$)`) |
| 354 | isHeadingMarkdown = regexp.MustCompile(`^\#+( |$)`) |
| 355 | ) |
| 356 | |
| 357 | // lesserHeading returns true if text is a heading of a lesser or equal level |
| 358 | // than that denoted by prefix. |
| 359 | func lesserHeading(isHeading *regexp.Regexp, text, prefix string) bool { |
| 360 | return isHeading.MatchString(text) && !strings.HasPrefix(text, prefix+prefix[:1]) |
| 361 | } |
| 362 | |
| 363 | // parseSections parses Sections from lines for the section level indicated by |
| 364 | // number (a nil number indicates the top level). |
| 365 | func parseSections(ctx *Context, name, prefix string, lines *Lines, number []int) ([]Section, error) { |
| 366 | isMarkdown := prefix[0] == '#' |
| 367 | isHeading := isHeadingLegacy |
| 368 | if isMarkdown { |
| 369 | isHeading = isHeadingMarkdown |
| 370 | } |
| 371 | var sections []Section |
| 372 | for i := 1; ; i++ { |
| 373 | // Next non-empty line is title. |
| 374 | text, ok := lines.nextNonEmpty() |
| 375 | for ok && text == "" { |
| 376 | text, ok = lines.next() |
| 377 | } |
| 378 | if !ok { |
| 379 | break |
| 380 | } |
| 381 | if text != prefix && !strings.HasPrefix(text, prefix+" ") { |
| 382 | lines.back() |
| 383 | break |
| 384 | } |
| 385 | // Markdown sections can end in {#id} to set the HTML anchor for the section. |
| 386 | // This is nicer than the default #TOC_1_2-style anchor. |
| 387 | title := strings.TrimSpace(text[len(prefix):]) |
| 388 | id := "" |
| 389 | if isMarkdown && strings.HasSuffix(title, "}") { |
| 390 | j := strings.LastIndex(title, "{#") |
| 391 | if j >= 0 { |
| 392 | id = title[j+2 : len(title)-1] |
| 393 | title = strings.TrimSpace(title[:j]) |
| 394 | } |
| 395 | } |
| 396 | section := Section{ |
| 397 | Number: append(append([]int{}, number...), i), |
| 398 | Title: title, |
| 399 | ID: id, |
| 400 | } |
| 401 | text, ok = lines.nextNonEmpty() |
| 402 | for ok && !lesserHeading(isHeading, text, prefix) { |
| 403 | var e Elem |
| 404 | r, _ := utf8.DecodeRuneInString(text) |
| 405 | switch { |
| 406 | case !isMarkdown && unicode.IsSpace(r): |
| 407 | i := strings.IndexFunc(text, func(r rune) bool { |
| 408 | return !unicode.IsSpace(r) |
| 409 | }) |
| 410 | if i < 0 { |
| 411 | break |
| 412 | } |
| 413 | indent := text[:i] |
| 414 | var s []string |
| 415 | for ok && (strings.HasPrefix(text, indent) || text == "") { |
| 416 | if text != "" { |
| 417 | text = text[i:] |
| 418 | } |
| 419 | s = append(s, text) |
| 420 | text, ok = lines.next() |
| 421 | } |
| 422 | lines.back() |
| 423 | pre := strings.Join(s, "\n") |
| 424 | raw := pre |
| 425 | pre = strings.Replace(pre, "\t", " ", -1) // browsers treat tabs badly |
| 426 | pre = strings.TrimRightFunc(pre, unicode.IsSpace) |
| 427 | e = Text{Lines: []string{pre}, Pre: true, Raw: raw} |
| 428 | case !isMarkdown && strings.HasPrefix(text, "- "): |
| 429 | var b []string |
| 430 | for { |
| 431 | if strings.HasPrefix(text, "- ") { |
| 432 | b = append(b, text[2:]) |
| 433 | } else if len(b) > 0 && strings.HasPrefix(text, " ") { |
| 434 | b[len(b)-1] += "\n" + strings.TrimSpace(text) |
| 435 | } else { |
| 436 | break |
| 437 | } |
| 438 | if text, ok = lines.next(); !ok { |
| 439 | break |
| 440 | } |
| 441 | } |
| 442 | lines.back() |
| 443 | e = List{Bullet: b} |
| 444 | case isSpeakerNote(text): |
| 445 | section.Notes = append(section.Notes, trimSpeakerNote(text)) |
| 446 | case strings.HasPrefix(text, prefix+prefix[:1]+" ") || text == prefix+prefix[:1]: |
| 447 | lines.back() |
| 448 | subsecs, err := parseSections(ctx, name, prefix+prefix[:1], lines, section.Number) |
| 449 | if err != nil { |
| 450 | return nil, err |
| 451 | } |
| 452 | for _, ss := range subsecs { |
| 453 | section.Elem = append(section.Elem, ss) |
| 454 | } |
| 455 | case strings.HasPrefix(text, prefix+prefix[:1]): |
| 456 | return nil, fmt.Errorf("%s:%d: badly nested section inside %s: %s", name, lines.line, prefix, text) |
| 457 | case strings.HasPrefix(text, "."): |
| 458 | args := strings.Fields(text) |
| 459 | if args[0] == ".background" { |
| 460 | section.Classes = append(section.Classes, "background") |
| 461 | section.Styles = append(section.Styles, "background-image: url('"+args[1]+"')") |
| 462 | break |
| 463 | } |
| 464 | parser := parsers[args[0]] |
| 465 | if parser == nil { |
| 466 | return nil, fmt.Errorf("%s:%d: unknown command %q", name, lines.line, text) |
| 467 | } |
| 468 | t, err := parser(ctx, name, lines.line, text) |
| 469 | if err != nil { |
| 470 | return nil, err |
| 471 | } |
| 472 | e = t |
| 473 | |
| 474 | case isMarkdown: |
| 475 | // Collect Markdown lines, including blank lines and indented text. |
| 476 | var block []string |
| 477 | endLine, endBlock := lines.line-1, -1 // end is last non-empty line |
| 478 | for ok { |
| 479 | trim := strings.TrimSpace(text) |
| 480 | if trim != "" { |
| 481 | // Command breaks text block. |
| 482 | // Section heading breaks text block in markdown. |
| 483 | if text[0] == '.' || text[0] == '#' || isSpeakerNote(text) { |
| 484 | break |
| 485 | } |
| 486 | if strings.HasPrefix(text, `\.`) { // Backslash escapes initial period. |
| 487 | text = text[1:] |
| 488 | } |
| 489 | endLine, endBlock = lines.line, len(block) |
| 490 | } |
| 491 | block = append(block, text) |
| 492 | text, ok = lines.next() |
| 493 | } |
| 494 | block = block[:endBlock+1] |
| 495 | lines.line = endLine + 1 |
| 496 | if len(block) == 0 { |
| 497 | break |
| 498 | } |
| 499 | |
| 500 | // Replace all leading tabs with 4 spaces, |
| 501 | // which render better in code blocks. |
| 502 | // CommonMark defines that for parsing the structure of the file |
| 503 | // a tab is equivalent to 4 spaces, so this change won't |
| 504 | // affect the later parsing at all. |
| 505 | // An alternative would be to apply this to code blocks after parsing, |
| 506 | // at the same time that we update <a> targets, but that turns out |
| 507 | // to be quite difficult to modify in the AST. |
| 508 | for i, line := range block { |
| 509 | if len(line) > 0 && line[0] == '\t' { |
| 510 | short := strings.TrimLeft(line, "\t") |
| 511 | line = strings.Repeat(" ", len(line)-len(short)) + short |
| 512 | block[i] = line |
| 513 | } |
| 514 | } |
| 515 | html, err := renderMarkdown([]byte(strings.Join(block, "\n"))) |
| 516 | if err != nil { |
| 517 | return nil, err |
| 518 | } |
| 519 | e = HTML{HTML: html} |
| 520 | |
| 521 | default: |
| 522 | // Collect text lines. |
| 523 | var block []string |
| 524 | for ok && strings.TrimSpace(text) != "" { |
| 525 | // Command breaks text block. |
| 526 | // Section heading breaks text block in markdown. |
| 527 | if text[0] == '.' || isSpeakerNote(text) { |
| 528 | lines.back() |
| 529 | break |
| 530 | } |
| 531 | if strings.HasPrefix(text, `\.`) { // Backslash escapes initial period. |
| 532 | text = text[1:] |
| 533 | } |
| 534 | block = append(block, text) |
| 535 | text, ok = lines.next() |
| 536 | } |
| 537 | if len(block) == 0 { |
| 538 | break |
| 539 | } |
| 540 | e = Text{Lines: block} |
| 541 | } |
| 542 | if e != nil { |
| 543 | section.Elem = append(section.Elem, e) |
| 544 | } |
| 545 | text, ok = lines.nextNonEmpty() |
| 546 | } |
| 547 | if isHeading.MatchString(text) { |
| 548 | lines.back() |
| 549 | } |
| 550 | sections = append(sections, section) |
| 551 | } |
| 552 | |
| 553 | if len(sections) == 0 { |
| 554 | return nil, fmt.Errorf("%s:%d: unexpected line: %s", name, lines.line+1, lines.text[lines.line]) |
| 555 | } |
| 556 | return sections, nil |
| 557 | } |
| 558 | |
| 559 | func parseHeader(doc *Doc, isMarkdown bool, lines *Lines) error { |
| 560 | var ok bool |
| 561 | // First non-empty line starts header. |
| 562 | doc.Title, ok = lines.nextNonEmpty() |
| 563 | if !ok { |
| 564 | return errors.New("unexpected EOF; expected title") |
| 565 | } |
| 566 | if isMarkdown { |
| 567 | doc.Title = strings.TrimSpace(strings.TrimPrefix(doc.Title, "#")) |
| 568 | } |
| 569 | |
| 570 | for { |
| 571 | text, ok := lines.next() |
| 572 | if !ok { |
| 573 | return errors.New("unexpected EOF") |
| 574 | } |
| 575 | if text == "" { |
| 576 | break |
| 577 | } |
| 578 | if isSpeakerNote(text) { |
| 579 | continue |
| 580 | } |
| 581 | if strings.HasPrefix(text, "Tags:") { |
| 582 | tags := strings.Split(text[len("Tags:"):], ",") |
| 583 | for i := range tags { |
| 584 | tags[i] = strings.TrimSpace(tags[i]) |
| 585 | } |
| 586 | doc.Tags = append(doc.Tags, tags...) |
| 587 | } else if strings.HasPrefix(text, "Summary:") { |
| 588 | doc.Summary = strings.TrimSpace(text[len("Summary:"):]) |
| 589 | } else if strings.HasPrefix(text, "OldURL:") { |
| 590 | doc.OldURL = append(doc.OldURL, strings.TrimSpace(text[len("OldURL:"):])) |
| 591 | } else if t, ok := parseTime(text); ok { |
| 592 | doc.Time = t |
| 593 | } else if doc.Subtitle == "" { |
| 594 | doc.Subtitle = text |
| 595 | } else { |
| 596 | return fmt.Errorf("unexpected header line: %q", text) |
| 597 | } |
| 598 | } |
| 599 | return nil |
| 600 | } |
| 601 | |
| 602 | func parseAuthors(name, sectionPrefix string, lines *Lines) (authors []Author, err error) { |
| 603 | // This grammar demarcates authors with blanks. |
| 604 | |
| 605 | // Skip blank lines. |
| 606 | if _, ok := lines.nextNonEmpty(); !ok { |
| 607 | return nil, errors.New("unexpected EOF") |
| 608 | } |
| 609 | lines.back() |
| 610 | |
| 611 | var a *Author |
| 612 | for { |
| 613 | text, ok := lines.next() |
| 614 | if !ok { |
| 615 | return nil, errors.New("unexpected EOF") |
| 616 | } |
| 617 | |
| 618 | // If we find a section heading, we're done. |
| 619 | if strings.HasPrefix(text, sectionPrefix) { |
| 620 | lines.back() |
| 621 | break |
| 622 | } |
| 623 | |
| 624 | if isSpeakerNote(text) { |
| 625 | continue |
| 626 | } |
| 627 | |
| 628 | // If we encounter a blank we're done with this author. |
| 629 | if a != nil && len(text) == 0 { |
| 630 | authors = append(authors, *a) |
| 631 | a = nil |
| 632 | continue |
| 633 | } |
| 634 | if a == nil { |
| 635 | a = new(Author) |
| 636 | } |
| 637 | |
| 638 | // Parse the line. Those that |
| 639 | // - begin with @ are twitter names, |
| 640 | // - contain slashes are links, or |
| 641 | // - contain an @ symbol are an email address. |
| 642 | // The rest is just text. |
| 643 | var el Elem |
| 644 | switch { |
| 645 | case strings.HasPrefix(text, "@"): |
| 646 | el = parseAuthorURL(name, "http://twitter.com/"+text[1:]) |
| 647 | case strings.Contains(text, ":"): |
| 648 | el = parseAuthorURL(name, text) |
| 649 | case strings.Contains(text, "@"): |
| 650 | el = parseAuthorURL(name, "mailto:"+text) |
| 651 | } |
| 652 | if l, ok := el.(Link); ok { |
| 653 | l.Label = text |
| 654 | el = l |
| 655 | } |
| 656 | if el == nil { |
| 657 | el = Text{Lines: []string{text}} |
| 658 | } |
| 659 | a.Elem = append(a.Elem, el) |
| 660 | } |
| 661 | if a != nil { |
| 662 | authors = append(authors, *a) |
| 663 | } |
| 664 | return authors, nil |
| 665 | } |
| 666 | |
| 667 | func parseAuthorURL(name, text string) Elem { |
| 668 | u, err := url.Parse(text) |
| 669 | if err != nil { |
| 670 | log.Printf("parsing %s author block: invalid URL %q: %v", name, text, err) |
| 671 | return nil |
| 672 | } |
| 673 | return Link{URL: u} |
| 674 | } |
| 675 | |
| 676 | func parseTime(text string) (t time.Time, ok bool) { |
| 677 | t, err := time.Parse("15:04 2 Jan 2006", text) |
| 678 | if err == nil { |
| 679 | return t, true |
| 680 | } |
| 681 | t, err = time.Parse("2 Jan 2006", text) |
| 682 | if err == nil { |
| 683 | // at 11am UTC it is the same date everywhere |
| 684 | t = t.Add(time.Hour * 11) |
| 685 | return t, true |
| 686 | } |
| 687 | return time.Time{}, false |
| 688 | } |
| 689 | |
| 690 | func isSpeakerNote(s string) bool { |
| 691 | return strings.HasPrefix(s, ": ") || s == ":" |
| 692 | } |
| 693 | |
| 694 | func trimSpeakerNote(s string) string { |
| 695 | if s == ":" { |
| 696 | return "" |
| 697 | } |
| 698 | return strings.TrimPrefix(s, ": ") |
| 699 | } |
| 700 | |
| 701 | func renderMarkdown(input []byte) (template.HTML, error) { |
| 702 | md := goldmark.New(goldmark.WithRendererOptions(html.WithUnsafe())) |
| 703 | reader := text.NewReader(input) |
| 704 | doc := md.Parser().Parse(reader) |
| 705 | fixupMarkdown(doc) |
| 706 | var b strings.Builder |
| 707 | if err := md.Renderer().Render(&b, input, doc); err != nil { |
| 708 | return "", err |
| 709 | } |
| 710 | return template.HTML(b.String()), nil |
| 711 | } |
| 712 | |
| 713 | func fixupMarkdown(n ast.Node) { |
| 714 | ast.Walk(n, func(n ast.Node, entering bool) (ast.WalkStatus, error) { |
| 715 | if entering { |
| 716 | switch n := n.(type) { |
| 717 | case *ast.Link: |
| 718 | n.SetAttributeString("target", []byte("_blank")) |
| 719 | // https://developers.google.com/web/tools/lighthouse/audits/noopener |
| 720 | n.SetAttributeString("rel", []byte("noopener")) |
| 721 | } |
| 722 | } |
| 723 | return ast.WalkContinue, nil |
| 724 | }) |
| 725 | } |
| 726 |
Members