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author | Chris <ccbrown112@gmail.com> | 2018-01-22 15:32:50 -0600 |
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committer | GitHub <noreply@github.com> | 2018-01-22 15:32:50 -0600 |
commit | 599991ea731953f772824ce3ed1e591246aa004f (patch) | |
tree | fca0f556f12e56bdcefa74ac6794dec64e04e3fc /utils/markdown/inlines.go | |
parent | a8445775351c32f8a12081f60bda2099571b2758 (diff) | |
download | chat-599991ea731953f772824ce3ed1e591246aa004f.tar.gz chat-599991ea731953f772824ce3ed1e591246aa004f.tar.bz2 chat-599991ea731953f772824ce3ed1e591246aa004f.zip |
PLT-3383: image proxy support (#7991)
* image proxy support
* go vet fix, remove mistakenly added coverage file
* fix test compile error
* add validation to config settings and documentation to model functions
* add message_source field to post
Diffstat (limited to 'utils/markdown/inlines.go')
-rw-r--r-- | utils/markdown/inlines.go | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/utils/markdown/inlines.go b/utils/markdown/inlines.go new file mode 100644 index 000000000..03da2f15c --- /dev/null +++ b/utils/markdown/inlines.go @@ -0,0 +1,489 @@ +// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved. +// See License.txt for license information. + +package markdown + +import ( + "container/list" + "strings" + "unicode" + "unicode/utf8" +) + +type Inline interface { + IsInline() bool +} + +type inlineBase struct{} + +func (inlineBase) IsInline() bool { return true } + +type Text struct { + inlineBase + + Text string +} + +type CodeSpan struct { + inlineBase + + Code string +} + +type HardLineBreak struct { + inlineBase +} + +type SoftLineBreak struct { + inlineBase +} + +type InlineLinkOrImage struct { + inlineBase + + Children []Inline + + RawDestination Range + + markdown string + rawTitle string +} + +func (i *InlineLinkOrImage) Destination() string { + return Unescape(i.markdown[i.RawDestination.Position:i.RawDestination.End]) +} + +func (i *InlineLinkOrImage) Title() string { + return Unescape(i.rawTitle) +} + +type InlineLink struct { + InlineLinkOrImage +} + +type InlineImage struct { + InlineLinkOrImage +} + +type ReferenceLinkOrImage struct { + inlineBase + *ReferenceDefinition + + Children []Inline +} + +type ReferenceLink struct { + ReferenceLinkOrImage +} + +type ReferenceImage struct { + ReferenceLinkOrImage +} + +type delimiterType int + +const ( + linkOpeningDelimiter delimiterType = iota + imageOpeningDelimiter +) + +type delimiter struct { + Type delimiterType + IsInactive bool + TextNode int + Range Range +} + +type inlineParser struct { + markdown string + ranges []Range + referenceDefinitions []*ReferenceDefinition + + raw string + position int + inlines []Inline + delimiterStack *list.List +} + +func newInlineParser(markdown string, ranges []Range, referenceDefinitions []*ReferenceDefinition) *inlineParser { + return &inlineParser{ + markdown: markdown, + ranges: ranges, + referenceDefinitions: referenceDefinitions, + delimiterStack: list.New(), + } +} + +func (p *inlineParser) parseBackticks() { + count := 1 + for i := p.position + 1; i < len(p.raw) && p.raw[i] == '`'; i++ { + count++ + } + opening := p.raw[p.position : p.position+count] + search := p.position + count + for search < len(p.raw) { + end := strings.Index(p.raw[search:], opening) + if end == -1 { + break + } + if search+end+count < len(p.raw) && p.raw[search+end+count] == '`' { + search += end + count + for search < len(p.raw) && p.raw[search] == '`' { + search++ + } + continue + } + code := strings.Join(strings.Fields(p.raw[p.position+count:search+end]), " ") + p.position = search + end + count + p.inlines = append(p.inlines, &CodeSpan{ + Code: code, + }) + return + } + p.position += len(opening) + p.inlines = append(p.inlines, &Text{ + Text: opening, + }) +} + +func (p *inlineParser) parseLineEnding() { + if p.position >= 1 && p.raw[p.position-1] == '\t' { + p.inlines = append(p.inlines, &HardLineBreak{}) + } else if p.position >= 2 && p.raw[p.position-1] == ' ' && (p.raw[p.position-2] == '\t' || p.raw[p.position-1] == ' ') { + p.inlines = append(p.inlines, &HardLineBreak{}) + } else { + p.inlines = append(p.inlines, &SoftLineBreak{}) + } + p.position++ + if p.position < len(p.raw) && p.raw[p.position] == '\n' { + p.position++ + } +} + +func (p *inlineParser) parseEscapeCharacter() { + if p.position+1 < len(p.raw) && isEscapableByte(p.raw[p.position+1]) { + p.inlines = append(p.inlines, &Text{ + Text: string(p.raw[p.position+1]), + }) + p.position += 2 + } else { + p.inlines = append(p.inlines, &Text{ + Text: `\`, + }) + p.position++ + } +} + +func (p *inlineParser) parseText() { + if next := strings.IndexAny(p.raw[p.position:], "\r\n\\`&![]"); next == -1 { + p.inlines = append(p.inlines, &Text{ + Text: strings.TrimRightFunc(p.raw[p.position:], isWhitespace), + }) + p.position = len(p.raw) + } else { + if p.raw[p.position+next] == '\r' || p.raw[p.position+next] == '\n' { + p.inlines = append(p.inlines, &Text{ + Text: strings.TrimRightFunc(p.raw[p.position:p.position+next], isWhitespace), + }) + } else { + p.inlines = append(p.inlines, &Text{ + Text: p.raw[p.position : p.position+next], + }) + } + p.position += next + } +} + +func (p *inlineParser) parseLinkOrImageDelimiter() { + if p.raw[p.position] == '[' { + p.inlines = append(p.inlines, &Text{ + Text: "[", + }) + p.delimiterStack.PushBack(&delimiter{ + Type: linkOpeningDelimiter, + TextNode: len(p.inlines) - 1, + Range: Range{p.position, p.position + 1}, + }) + p.position++ + } else if p.raw[p.position] == '!' && p.position+1 < len(p.raw) && p.raw[p.position+1] == '[' { + p.inlines = append(p.inlines, &Text{ + Text: "![", + }) + p.delimiterStack.PushBack(&delimiter{ + Type: imageOpeningDelimiter, + TextNode: len(p.inlines) - 1, + Range: Range{p.position, p.position + 2}, + }) + p.position += 2 + } else { + p.inlines = append(p.inlines, &Text{ + Text: "!", + }) + p.position++ + } +} + +func (p *inlineParser) peekAtInlineLinkDestinationAndTitle(position int) (destination, title Range, end int, ok bool) { + if position >= len(p.raw) || p.raw[position] != '(' { + return + } + position++ + + destinationStart := nextNonWhitespace(p.raw, position) + if destinationStart >= len(p.raw) { + return + } else if p.raw[destinationStart] == ')' { + return Range{destinationStart, destinationStart}, Range{destinationStart, destinationStart}, destinationStart + 1, true + } + + destination, end, ok = parseLinkDestination(p.raw, destinationStart) + if !ok { + return + } + position = end + + if position < len(p.raw) && isWhitespaceByte(p.raw[position]) { + titleStart := nextNonWhitespace(p.raw, position) + if titleStart >= len(p.raw) { + return + } else if p.raw[titleStart] == ')' { + return destination, Range{titleStart, titleStart}, titleStart + 1, true + } + + title, end, ok = parseLinkTitle(p.raw, titleStart) + if !ok { + return + } + position = end + } + + closingPosition := nextNonWhitespace(p.raw, position) + if closingPosition >= len(p.raw) || p.raw[closingPosition] != ')' { + return Range{}, Range{}, 0, false + } + + return destination, title, closingPosition + 1, true +} + +func (p *inlineParser) referenceDefinition(label string) *ReferenceDefinition { + clean := strings.Join(strings.Fields(label), " ") + for _, d := range p.referenceDefinitions { + if strings.EqualFold(clean, strings.Join(strings.Fields(d.Label()), " ")) { + return d + } + } + return nil +} + +func (p *inlineParser) lookForLinkOrImage() { + for element := p.delimiterStack.Back(); element != nil; element = element.Prev() { + d := element.Value.(*delimiter) + if d.Type != imageOpeningDelimiter && d.Type != linkOpeningDelimiter { + continue + } + if d.IsInactive { + p.delimiterStack.Remove(element) + break + } + + var inline Inline + + if destination, title, next, ok := p.peekAtInlineLinkDestinationAndTitle(p.position + 1); ok { + destinationMarkdownPosition := relativeToAbsolutePosition(p.ranges, destination.Position) + linkOrImage := InlineLinkOrImage{ + Children: append([]Inline(nil), p.inlines[d.TextNode+1:]...), + RawDestination: Range{destinationMarkdownPosition, destinationMarkdownPosition + destination.End - destination.Position}, + markdown: p.markdown, + rawTitle: p.raw[title.Position:title.End], + } + if d.Type == imageOpeningDelimiter { + inline = &InlineImage{linkOrImage} + } else { + inline = &InlineLink{linkOrImage} + } + p.position = next + } else { + referenceLabel := "" + label, next, hasLinkLabel := parseLinkLabel(p.raw, p.position+1) + if hasLinkLabel && label.End > label.Position { + referenceLabel = p.raw[label.Position:label.End] + } else { + referenceLabel = p.raw[d.Range.End:p.position] + if !hasLinkLabel { + next = p.position + 1 + } + } + if referenceLabel != "" { + if reference := p.referenceDefinition(referenceLabel); reference != nil { + linkOrImage := ReferenceLinkOrImage{ + ReferenceDefinition: reference, + Children: append([]Inline(nil), p.inlines[d.TextNode+1:]...), + } + if d.Type == imageOpeningDelimiter { + inline = &ReferenceImage{linkOrImage} + } else { + inline = &ReferenceLink{linkOrImage} + } + p.position = next + } + } + } + + if inline != nil { + if d.Type == imageOpeningDelimiter { + p.inlines = append(p.inlines[:d.TextNode], inline) + } else { + p.inlines = append(p.inlines[:d.TextNode], inline) + for element := element.Prev(); element != nil; element = element.Prev() { + if d := element.Value.(*delimiter); d.Type == linkOpeningDelimiter { + d.IsInactive = true + } + } + } + p.delimiterStack.Remove(element) + return + } else { + p.delimiterStack.Remove(element) + break + } + } + p.inlines = append(p.inlines, &Text{ + Text: "]", + }) + p.position++ +} + +func CharacterReference(ref string) string { + if ref == "" { + return "" + } + if ref[0] == '#' { + if len(ref) < 2 { + return "" + } + n := 0 + if ref[1] == 'X' || ref[1] == 'x' { + if len(ref) < 3 { + return "" + } + for i := 2; i < len(ref); i++ { + if i > 9 { + return "" + } + d := ref[i] + switch { + case d >= '0' && d <= '9': + n = n*16 + int(d-'0') + case d >= 'a' && d <= 'f': + n = n*16 + 10 + int(d-'a') + case d >= 'A' && d <= 'F': + n = n*16 + 10 + int(d-'A') + default: + return "" + } + } + } else { + for i := 1; i < len(ref); i++ { + if i > 8 || ref[i] < '0' || ref[i] > '9' { + return "" + } + n = n*10 + int(ref[i]-'0') + } + } + c := rune(n) + if c == '\u0000' || !utf8.ValidRune(c) { + return string(unicode.ReplacementChar) + } + return string(c) + } + if entity, ok := htmlEntities[ref]; ok { + return entity + } + return "" +} + +func (p *inlineParser) parseCharacterReference() { + p.position++ + if semicolon := strings.IndexByte(p.raw[p.position:], ';'); semicolon == -1 { + p.inlines = append(p.inlines, &Text{ + Text: "&", + }) + } else if s := CharacterReference(p.raw[p.position : p.position+semicolon]); s != "" { + p.position += semicolon + 1 + p.inlines = append(p.inlines, &Text{ + Text: s, + }) + } else { + p.inlines = append(p.inlines, &Text{ + Text: "&", + }) + } +} + +func (p *inlineParser) Parse() []Inline { + for _, r := range p.ranges { + p.raw += p.markdown[r.Position:r.End] + } + + for p.position < len(p.raw) { + c, _ := utf8.DecodeRuneInString(p.raw[p.position:]) + + switch c { + case '\r', '\n': + p.parseLineEnding() + case '\\': + p.parseEscapeCharacter() + case '`': + p.parseBackticks() + case '&': + p.parseCharacterReference() + case '!', '[': + p.parseLinkOrImageDelimiter() + case ']': + p.lookForLinkOrImage() + default: + p.parseText() + } + } + + return p.inlines +} + +func ParseInlines(markdown string, ranges []Range, referenceDefinitions []*ReferenceDefinition) (inlines []Inline) { + return newInlineParser(markdown, ranges, referenceDefinitions).Parse() +} + +func Unescape(markdown string) string { + ret := "" + + position := 0 + for position < len(markdown) { + c, cSize := utf8.DecodeRuneInString(markdown[position:]) + + switch c { + case '\\': + if position+1 < len(markdown) && isEscapableByte(markdown[position+1]) { + ret += string(markdown[position+1]) + position += 2 + } else { + ret += `\` + position++ + } + case '&': + position++ + if semicolon := strings.IndexByte(markdown[position:], ';'); semicolon == -1 { + ret += "&" + } else if s := CharacterReference(markdown[position : position+semicolon]); s != "" { + position += semicolon + 1 + ret += s + } else { + ret += "&" + } + default: + ret += string(c) + position += cSize + } + } + + return ret +} |