// Minify minifies HTML data, it reads from r and writes to w. func Minify(m minify.Minifier, _ string, w io.Writer, r io.Reader) error { var rawTag html.Hash var rawTagMediatype []byte omitSpace := true // if true the next leading space is omitted defaultScriptType := "text/javascript" defaultStyleType := "text/css" defaultInlineStyleType := "text/css;inline=1" attrMinifyBuffer := buffer.NewWriter(make([]byte, 0, 64)) attrByteBuffer := make([]byte, 0, 64) attrIntBuffer := make([]int, 0, maxAttrLookup) attrTokenBuffer := make([]*html.Token, 0, maxAttrLookup) l := html.NewLexer(r) tb := html.NewTokenBuffer(l) for { t := *tb.Shift() SWITCH: switch t.TokenType { case html.ErrorToken: if l.Err() == io.EOF { return nil } return l.Err() case html.DoctypeToken: if _, err := w.Write([]byte("<!doctype html>")); err != nil { return err } case html.CommentToken: // TODO: ensure that nested comments are handled properly (lexer doesn't handle this!) var comment []byte if bytes.HasPrefix(t.Data, []byte("[if")) { comment = append(append([]byte("<!--"), t.Data...), []byte("-->")...) } else if bytes.HasSuffix(t.Data, []byte("--")) { // only occurs when mixed up with conditional comments comment = append(append([]byte("<!"), t.Data...), '>') } if _, err := w.Write(comment); err != nil { return err } case html.TextToken: // CSS and JS minifiers for inline code if rawTag != 0 { if rawTag == html.Style || rawTag == html.Script || rawTag == html.Iframe || rawTag == html.Svg || rawTag == html.Math { var mediatype string if rawTag == html.Iframe { mediatype = "text/html" } else if len(rawTagMediatype) > 0 { mediatype = string(rawTagMediatype) } else if rawTag == html.Script { mediatype = defaultScriptType } else if rawTag == html.Style { mediatype = defaultStyleType } else if rawTag == html.Svg { mediatype = "image/svg+xml" } else if rawTag == html.Math { mediatype = "application/mathml+xml" } // ignore CDATA if trimmedData := parse.Trim(t.Data, parse.IsWhitespace); len(trimmedData) > 12 && bytes.Equal(trimmedData[:9], []byte("<![CDATA[")) && bytes.Equal(trimmedData[len(trimmedData)-3:], []byte("]]>")) { t.Data = trimmedData[9 : len(trimmedData)-3] } if err := m.Minify(mediatype, w, buffer.NewReader(t.Data)); err != nil { if _, err := w.Write(t.Data); err != nil { return err } } } else if _, err := w.Write(t.Data); err != nil { return err } if !nonPhrasingTagMap[rawTag] && rawTag != html.Script { omitSpace = len(t.Data) > 0 && t.Data[len(t.Data)-1] == ' ' } } else { t.Data = parse.ReplaceMultiple(t.Data, parse.IsWhitespace, ' ') // whitespace removal; trim left if omitSpace && t.Data[0] == ' ' { t.Data = t.Data[1:] } // whitespace removal; trim right omitSpace = false if len(t.Data) == 0 { omitSpace = true } else if t.Data[len(t.Data)-1] == ' ' { omitSpace = true i := 0 for { next := tb.Peek(i) // trim if EOF, text token with leading whitespace or block token if next.TokenType == html.ErrorToken { t.Data = t.Data[:len(t.Data)-1] omitSpace = false break } else if next.TokenType == html.TextToken { // remove if the text token starts with a whitespace if len(next.Data) > 0 && parse.IsWhitespace(next.Data[0]) { t.Data = t.Data[:len(t.Data)-1] omitSpace = false } break } else if next.TokenType == html.StartTagToken || next.TokenType == html.EndTagToken { // remove when followed up by a block tag if nonPhrasingTagMap[next.Hash] { t.Data = t.Data[:len(t.Data)-1] omitSpace = false break } else if next.TokenType == html.StartTagToken { break } } i++ } } if _, err := w.Write(t.Data); err != nil { return err } } case html.StartTagToken, html.EndTagToken: rawTag = 0 hasAttributes := false if t.TokenType == html.StartTagToken { if next := tb.Peek(0); next.TokenType == html.AttributeToken { hasAttributes = true } if rawTagMap[t.Hash] { // ignore empty script and style tags if !hasAttributes && (t.Hash == html.Script || t.Hash == html.Style) { if next := tb.Peek(1); next.TokenType == html.EndTagToken { tb.Shift() tb.Shift() break } } rawTag = t.Hash rawTagMediatype = []byte{} } } if nonPhrasingTagMap[t.Hash] { omitSpace = true // omit spaces after block elements } // remove superfluous ending tags if !hasAttributes && (t.Hash == html.Html || t.Hash == html.Head || t.Hash == html.Body || t.Hash == html.Colgroup) { break } else if t.TokenType == html.EndTagToken { if t.Hash == html.Thead || t.Hash == html.Tbody || t.Hash == html.Tfoot || t.Hash == html.Tr || t.Hash == html.Th || t.Hash == html.Td || t.Hash == html.Optgroup || t.Hash == html.Option || t.Hash == html.Dd || t.Hash == html.Dt || t.Hash == html.Li || t.Hash == html.Rb || t.Hash == html.Rt || t.Hash == html.Rtc || t.Hash == html.Rp { break } else if t.Hash == html.P { i := 0 for { next := tb.Peek(i) i++ // continue if text token is empty or whitespace if next.TokenType == html.TextToken && parse.IsAllWhitespace(next.Data) { continue } if next.TokenType == html.ErrorToken || next.TokenType == html.EndTagToken && next.Hash != html.A || next.TokenType == html.StartTagToken && nonPhrasingTagMap[next.Hash] { break SWITCH } break } } } // write tag if t.TokenType == html.EndTagToken { if _, err := w.Write(endBytes); err != nil { return err } } else { if _, err := w.Write(ltBytes); err != nil { return err } } if _, err := w.Write(t.Data); err != nil { return err } if hasAttributes { // rewrite attributes with interdependent conditions if t.Hash == html.A { if attr := getAttributes(tb, &attrIntBuffer, &attrTokenBuffer, html.Id, html.Name, html.Rel, html.Href); attr != nil { if id := attr[0]; id != nil { if name := attr[1]; name != nil && parse.Equal(id.AttrVal, name.AttrVal) { name.Data = nil } } // TODO: omit http or https according to URL, specified through options // if rel := attr[2]; rel == nil || !parse.EqualFold(rel.AttrVal, externalBytes) { // if href := attr[3]; href != nil { // if len(href.AttrVal) > 5 && parse.EqualFold(href.AttrVal[:4], []byte{'h', 't', 't', 'p'}) { // if href.AttrVal[4] == ':' { // href.AttrVal = href.AttrVal[5:] // } else if (href.AttrVal[4] == 's' || href.AttrVal[4] == 'S') && href.AttrVal[5] == ':' { // href.AttrVal = href.AttrVal[6:] // } // } // } // } } } else if t.Hash == html.Meta { if attr := getAttributes(tb, &attrIntBuffer, &attrTokenBuffer, html.Content, html.Http_Equiv, html.Charset, html.Name); attr != nil { if content := attr[0]; content != nil { if httpEquiv := attr[1]; httpEquiv != nil { content.AttrVal = minify.ContentType(content.AttrVal) if charset := attr[2]; charset == nil && parse.EqualFold(httpEquiv.AttrVal, []byte("content-type")) && parse.Equal(content.AttrVal, []byte("text/html;charset=utf-8")) { httpEquiv.Data = nil content.Data = []byte("charset") content.Hash = html.Charset content.AttrVal = []byte("utf-8") } else if parse.EqualFold(httpEquiv.AttrVal, []byte("content-style-type")) { defaultStyleType = string(content.AttrVal) defaultInlineStyleType = defaultStyleType + ";inline=1" } else if parse.EqualFold(httpEquiv.AttrVal, []byte("content-script-type")) { defaultScriptType = string(content.AttrVal) } } if name := attr[3]; name != nil { if parse.EqualFold(name.AttrVal, []byte("keywords")) { content.AttrVal = bytes.Replace(content.AttrVal, []byte(", "), []byte(","), -1) } else if parse.EqualFold(name.AttrVal, []byte("viewport")) { content.AttrVal = bytes.Replace(content.AttrVal, []byte(" "), []byte(""), -1) } } } } } else if t.Hash == html.Script { if attr := getAttributes(tb, &attrIntBuffer, &attrTokenBuffer, html.Src, html.Charset); attr != nil { if src := attr[0]; src != nil { if charset := attr[1]; charset != nil { charset.Data = nil } } } } // write attributes for { attr := *tb.Shift() if attr.TokenType != html.AttributeToken { break } else if attr.Data == nil { continue // removed attribute } val := attr.AttrVal if len(val) > 1 && (val[0] == '"' || val[0] == '\'') { val = parse.Trim(val[1:len(val)-1], parse.IsWhitespace) } if len(val) == 0 && (attr.Hash == html.Class || attr.Hash == html.Dir || attr.Hash == html.Id || attr.Hash == html.Lang || attr.Hash == html.Name || attr.Hash == html.Title || attr.Hash == html.Action && t.Hash == html.Form || attr.Hash == html.Value && t.Hash == html.Input) { continue // omit empty attribute values } if caseInsensitiveAttrMap[attr.Hash] { val = parse.ToLower(val) if attr.Hash == html.Enctype || attr.Hash == html.Codetype || attr.Hash == html.Accept || attr.Hash == html.Type && (t.Hash == html.A || t.Hash == html.Link || t.Hash == html.Object || t.Hash == html.Param || t.Hash == html.Script || t.Hash == html.Style || t.Hash == html.Source) { val = minify.ContentType(val) } } if rawTag != 0 && attr.Hash == html.Type { rawTagMediatype = val } // default attribute values can be ommited if attr.Hash == html.Type && (t.Hash == html.Script && parse.Equal(val, []byte("text/javascript")) || t.Hash == html.Style && parse.Equal(val, []byte("text/css")) || t.Hash == html.Link && parse.Equal(val, []byte("text/css")) || t.Hash == html.Input && parse.Equal(val, []byte("text")) || t.Hash == html.Button && parse.Equal(val, []byte("submit"))) || attr.Hash == html.Language && t.Hash == html.Script || attr.Hash == html.Method && parse.Equal(val, []byte("get")) || attr.Hash == html.Enctype && parse.Equal(val, []byte("application/x-www-form-urlencoded")) || attr.Hash == html.Colspan && parse.Equal(val, []byte("1")) || attr.Hash == html.Rowspan && parse.Equal(val, []byte("1")) || attr.Hash == html.Shape && parse.Equal(val, []byte("rect")) || attr.Hash == html.Span && parse.Equal(val, []byte("1")) || attr.Hash == html.Clear && parse.Equal(val, []byte("none")) || attr.Hash == html.Frameborder && parse.Equal(val, []byte("1")) || attr.Hash == html.Scrolling && parse.Equal(val, []byte("auto")) || attr.Hash == html.Valuetype && parse.Equal(val, []byte("data")) || attr.Hash == html.Media && t.Hash == html.Style && parse.Equal(val, []byte("all")) { continue } // CSS and JS minifiers for attribute inline code if attr.Hash == html.Style { attrMinifyBuffer.Reset() if m.Minify(defaultInlineStyleType, attrMinifyBuffer, buffer.NewReader(val)) == nil { val = attrMinifyBuffer.Bytes() } if len(val) == 0 { continue } } else if len(attr.Data) > 2 && attr.Data[0] == 'o' && attr.Data[1] == 'n' { if len(val) >= 11 && parse.EqualFold(val[:11], []byte("javascript:")) { val = val[11:] } attrMinifyBuffer.Reset() if m.Minify(defaultScriptType, attrMinifyBuffer, buffer.NewReader(val)) == nil { val = attrMinifyBuffer.Bytes() } if len(val) == 0 { continue } } else if len(val) > 5 && urlAttrMap[attr.Hash] { // anchors are already handled // TODO: omit http or https according to URL, specified through options //if t.Hash != html.A { // if parse.EqualFold(val[:4], []byte{'h', 't', 't', 'p'}) { // if val[4] == ':' { // val = val[5:] // } else if (val[4] == 's' || val[4] == 'S') && val[5] == ':' { // val = val[6:] // } // } // } else if parse.EqualFold(val[:5], []byte{'d', 'a', 't', 'a', ':'}) { val = minify.DataURI(m, val) } } if _, err := w.Write(spaceBytes); err != nil { return err } if _, err := w.Write(attr.Data); err != nil { return err } if len(val) > 0 && !booleanAttrMap[attr.Hash] { if _, err := w.Write(isBytes); err != nil { return err } // no quotes if possible, else prefer single or double depending on which occurs more often in value val = html.EscapeAttrVal(&attrByteBuffer, attr.AttrVal, val) if _, err := w.Write(val); err != nil { return err } } } } if _, err := w.Write(gtBytes); err != nil { return err } } } }
// Minify minifies SVG data, it reads from r and writes to w. func Minify(m minify.Minifier, _ string, w io.Writer, r io.Reader) error { var tag svg.Hash attrMinifyBuffer := buffer.NewWriter(make([]byte, 0, 64)) attrByteBuffer := make([]byte, 0, 64) l := xml.NewLexer(r) tb := xml.NewTokenBuffer(l) for { t := *tb.Shift() if t.TokenType == xml.CDATAToken { var useCDATA bool if t.Data, useCDATA = xml.EscapeCDATAVal(&attrByteBuffer, t.Data); !useCDATA { t.TokenType = xml.TextToken } } SWITCH: switch t.TokenType { case xml.ErrorToken: if l.Err() == io.EOF { return nil } return l.Err() case xml.TextToken: t.Data = parse.ReplaceMultiple(parse.Trim(t.Data, parse.IsWhitespace), parse.IsWhitespace, ' ') if tag == svg.Style && len(t.Data) > 0 { if err := m.Minify("text/css", w, buffer.NewReader(t.Data)); err != nil { if err == minify.ErrNotExist { // no minifier, write the original if _, err := w.Write(t.Data); err != nil { return err } } else { return err } } } else if _, err := w.Write(t.Data); err != nil { return err } case xml.CDATAToken: if _, err := w.Write(cdataStartBytes); err != nil { return err } t.Data = parse.ReplaceMultiple(parse.Trim(t.Data, parse.IsWhitespace), parse.IsWhitespace, ' ') if tag == svg.Style && len(t.Data) > 0 { if err := m.Minify("text/css", w, buffer.NewReader(t.Data)); err != nil { if err == minify.ErrNotExist { // no minifier, write the original if _, err := w.Write(t.Data); err != nil { return err } } else { return err } } } else if _, err := w.Write(t.Data); err != nil { return err } if _, err := w.Write(cdataEndBytes); err != nil { return err } case xml.StartTagPIToken: for { if t := *tb.Shift(); t.TokenType == xml.StartTagClosePIToken || t.TokenType == xml.ErrorToken { break } } case xml.StartTagToken: tag = svg.ToHash(t.Data) if containerTagMap[tag] { // skip empty containers i := 0 for { next := tb.Peek(i) i++ if next.TokenType == xml.EndTagToken && svg.ToHash(next.Data) == tag || next.TokenType == xml.StartTagCloseVoidToken || next.TokenType == xml.ErrorToken { for j := 0; j < i; j++ { tb.Shift() } break SWITCH } else if next.TokenType != xml.AttributeToken && next.TokenType != xml.StartTagCloseToken { break } } } else if tag == svg.Metadata { for { if t := *tb.Shift(); t.TokenType == xml.EndTagToken && svg.ToHash(t.Data) == tag || t.TokenType == xml.StartTagCloseVoidToken || t.TokenType == xml.ErrorToken { break } } break } else if tag == svg.Line || tag == svg.Rect { // TODO: shape2path also for polygon and polyline // x1, y1, x2, y2 float64 := 0, 0, 0, 0 // valid := true // i := 0 // for { // next := tb.Peek(i) // i++ // if next.TokenType != xml.AttributeToken { // break // } // v *int // attr := svg.ToHash(next.Data) // if tag == svg.Line { // if attr == svg.X1 { // v = &x1 // } else if attr == svg.Y1 { // v = &y1 // } else if attr == svg.X2 { // v = &x2 // } else if attr == svg.Y2 { // v = &Y2 // } else { // continue // } // } else if attr == svg.X { // rect // v = &x1 // } else if attr == svg.Y { // v = &y1 // } else if attr == svg.Width { // v = &x2 // } else if attr == svg.Height { // v = &Y2 // } else if attr == svg.Rx || attr == svg.Ry { // valid = false // break // } else { // continue // } // } // if valid { // t.Data = pathBytes // } } if _, err := w.Write(ltBytes); err != nil { return err } if _, err := w.Write(t.Data); err != nil { return err } case xml.AttributeToken: if len(t.AttrVal) < 2 { continue } attr := svg.ToHash(t.Data) val := parse.ReplaceMultiple(parse.Trim(t.AttrVal[1:len(t.AttrVal)-1], parse.IsWhitespace), parse.IsWhitespace, ' ') if tag == svg.Svg && attr == svg.Version { continue } if _, err := w.Write(spaceBytes); err != nil { return err } if _, err := w.Write(t.Data); err != nil { return err } if _, err := w.Write(isBytes); err != nil { return err } if attr == svg.Style { attrMinifyBuffer.Reset() if m.Minify("text/css;inline=1", attrMinifyBuffer, buffer.NewReader(val)) == nil { val = attrMinifyBuffer.Bytes() } } else if attr == svg.D { val = shortenPathData(val) } else if attr == svg.ViewBox { j := 0 newVal := val[:0] for i := 0; i < 4; i++ { if i != 0 { if j >= len(val) || val[j] != ' ' && val[j] != ',' { newVal = append(newVal, val[j:]...) break } newVal = append(newVal, ' ') j++ } if dim, n := shortenDimension(val[j:]); n > 0 { newVal = append(newVal, dim...) j += n } else { newVal = append(newVal, val[j:]...) break } } val = newVal } else if colorAttrMap[attr] && len(val) > 0 { parse.ToLower(val) if val[0] == '#' { if name, ok := minifyCSS.ShortenColorHex[string(val)]; ok { val = name } else if len(val) == 7 && val[1] == val[2] && val[3] == val[4] && val[5] == val[6] { val[2] = val[3] val[3] = val[5] val = val[:4] } } else if hex, ok := minifyCSS.ShortenColorName[css.ToHash(val)]; ok { val = hex } else if len(val) > 5 && parse.Equal(val[:4], []byte("rgb(")) && val[len(val)-1] == ')' { // TODO: handle rgb(x, y, z) and hsl(x, y, z) } } else if dim, n := shortenDimension(val); n == len(val) { val = dim } // prefer single or double quotes depending on what occurs more often in value val = xml.EscapeAttrVal(&attrByteBuffer, val) if _, err := w.Write(val); err != nil { return err } case xml.StartTagCloseToken: next := tb.Peek(0) skipExtra := false if next.TokenType == xml.TextToken && parse.IsAllWhitespace(next.Data) { next = tb.Peek(1) skipExtra = true } if next.TokenType == xml.EndTagToken { // collapse empty tags to single void tag tb.Shift() if skipExtra { tb.Shift() } if _, err := w.Write(voidBytes); err != nil { return err } } else { if _, err := w.Write(gtBytes); err != nil { return err } } case xml.StartTagCloseVoidToken: if _, err := w.Write(voidBytes); err != nil { return err } case xml.EndTagToken: if _, err := w.Write(endBytes); err != nil { return err } if _, err := w.Write(t.Data); err != nil { return err } if _, err := w.Write(gtBytes); err != nil { return err } } } }
// Minify minifies XML data, it reads from r and writes to w. func Minify(m minify.Minifier, _ string, w io.Writer, r io.Reader) error { precededBySpace := true // on true the next text token must not start with a space attrByteBuffer := make([]byte, 0, 64) l := xml.NewLexer(r) tb := xml.NewTokenBuffer(l) for { t := *tb.Shift() if t.TokenType == xml.CDATAToken { var useCDATA bool if t.Data, useCDATA = xml.EscapeCDATAVal(&attrByteBuffer, t.Data); !useCDATA { t.TokenType = xml.TextToken } } switch t.TokenType { case xml.ErrorToken: if l.Err() == io.EOF { return nil } return l.Err() case xml.DOCTYPEToken: if _, err := w.Write(doctypeBytes); err != nil { return err } if _, err := w.Write(t.Data); err != nil { return err } if _, err := w.Write(gtBytes); err != nil { return err } case xml.CDATAToken: if _, err := w.Write(cdataStartBytes); err != nil { return err } if _, err := w.Write(t.Data); err != nil { return err } if _, err := w.Write(cdataEndBytes); err != nil { return err } case xml.TextToken: if t.Data = parse.ReplaceMultiple(t.Data, parse.IsWhitespace, ' '); len(t.Data) > 0 { // whitespace removal; trim left if t.Data[0] == ' ' && precededBySpace { t.Data = t.Data[1:] } // whitespace removal; trim right precededBySpace = false if len(t.Data) == 0 { precededBySpace = true } else if t.Data[len(t.Data)-1] == ' ' { precededBySpace = true i := 0 for { next := tb.Peek(i) // trim if EOF, text token with whitespace begin or block token if next.TokenType == xml.StartTagToken || next.TokenType == xml.EndTagToken || next.TokenType == xml.ErrorToken { t.Data = t.Data[:len(t.Data)-1] precededBySpace = false break } else if next.TokenType == xml.TextToken { // remove if the text token starts with a whitespace if len(next.Data) > 0 && parse.IsWhitespace(next.Data[0]) { t.Data = t.Data[:len(t.Data)-1] precededBySpace = false } break } i++ } } if _, err := w.Write(t.Data); err != nil { return err } } case xml.StartTagToken: if _, err := w.Write(ltBytes); err != nil { return err } if _, err := w.Write(t.Data); err != nil { return err } case xml.StartTagPIToken: if _, err := w.Write(ltPIBytes); err != nil { return err } if _, err := w.Write(t.Data); err != nil { return err } case xml.AttributeToken: if _, err := w.Write(spaceBytes); err != nil { return err } if _, err := w.Write(t.Data); err != nil { return err } if _, err := w.Write(isBytes); err != nil { return err } if len(t.AttrVal) < 2 { if _, err := w.Write(t.AttrVal); err != nil { return err } } else { // prefer single or double quotes depending on what occurs more often in value val := xml.EscapeAttrVal(&attrByteBuffer, t.AttrVal[1:len(t.AttrVal)-1]) if _, err := w.Write(val); err != nil { return err } } case xml.StartTagCloseToken: next := tb.Peek(0) skipExtra := false if next.TokenType == xml.TextToken && parse.IsAllWhitespace(next.Data) { next = tb.Peek(1) skipExtra = true } if next.TokenType == xml.EndTagToken { // collapse empty tags to single void tag tb.Shift() if skipExtra { tb.Shift() } if _, err := w.Write(voidBytes); err != nil { return err } } else { if _, err := w.Write(gtBytes); err != nil { return err } } case xml.StartTagCloseVoidToken: if _, err := w.Write(voidBytes); err != nil { return err } case xml.StartTagClosePIToken: if _, err := w.Write(gtPIBytes); err != nil { return err } case xml.EndTagToken: if _, err := w.Write(endBytes); err != nil { return err } if _, err := w.Write(t.Data); err != nil { return err } if _, err := w.Write(gtBytes); err != nil { return err } } } }