bbcode - bbcodehtml/tags.go

     1  package bbcodehtml // import "vimagination.zapto.org/bbcode/bbcodehtml"
     2  
     3  import (
     4  	"bytes"
     5  	"html/template"
     6  	"strconv"
     7  	"strings"
     8  
     9  	"vimagination.zapto.org/bbcode"
    10  )
    11  
    12  var (
    13  	alignLeft   = []byte("left")
    14  	alignRight  = []byte("right")
    15  	alignCentre = []byte("center")
    16  	alignFull   = []byte("justify")
    17  
    18  	leftOpen   = []byte("<div style=\"text-align: left\">")
    19  	centreOpen = []byte("<div style=\"text-align: center\">")
    20  	rightOpen  = []byte("<div style=\"text-align: right\">")
    21  	fullOpen   = []byte("<div style=\"text-align: justify\">")
    22  
    23  	divOpen        = []byte("<div>")
    24  	divPartialOpen = divOpen[:4]
    25  	divClose       = []byte("</div>")
    26  
    27  	spanOpen        = []byte("<span>")
    28  	spanPartialOpen = spanOpen[:5]
    29  	spanClose       = []byte("</span>")
    30  
    31  	attrTagClose = []byte("\">")
    32  	tagClose     = attrTagClose[:1]
    33  	attrClose    = attrTagClose[1:]
    34  	sizeClose    = []byte("pt\"")
    35  
    36  	alignAttr  = []byte(" style=\"text-align: ")
    37  	colourAttr = []byte(" style=\"color: ")
    38  	fontAttr   = []byte(" style=\"font-family: ")
    39  	sizeAttr   = []byte(" style=\"font-size: ")
    40  )
    41  
    42  // The following are some predefined bbcode tags for common applications
    43  var (
    44  	Align = bbcode.NewAttributeTag("align", divPartialOpen, tagClose, alignAttr, attrClose, divClose, bbcode.AttrFilterFunc(alignFilter))
    45  
    46  	LeftAlign   = bbcode.NewTag("left", leftOpen, divClose)
    47  	CentreAlign = bbcode.NewTag("centre", centreOpen, divClose)
    48  	CenterAlign = bbcode.NewTag("center", centreOpen, divClose)
    49  	RightAlign  = bbcode.NewTag("right", rightOpen, divClose)
    50  	FullAlign   = bbcode.NewTag("full", fullOpen, divClose)
    51  
    52  	Color  = bbcode.NewAttributeTag("color", spanPartialOpen, tagClose, colourAttr, attrClose, spanClose, Colours)
    53  	Colour = bbcode.NewAttributeTag("colour", spanPartialOpen, tagClose, colourAttr, attrClose, spanClose, Colours)
    54  
    55  	Font = bbcode.NewAttributeTag("font", spanPartialOpen, tagClose, fontAttr, attrClose, spanClose, Fonts)
    56  
    57  	Bold         = bbcode.NewTag("b", []byte("<b>"), []byte("</b>"))
    58  	Italic       = bbcode.NewTag("i", []byte("<i>"), []byte("</i>"))
    59  	Strikethough = bbcode.NewTag("s", []byte("<s>"), []byte("</s>"))
    60  	Underline    = bbcode.NewTag("u", []byte("<u>"), []byte("</u>"))
    61  
    62  	Size = bbcode.NewAttributeTag("size", spanPartialOpen, tagClose, sizeAttr, sizeClose, spanClose, bbcode.AttrFilterFunc(sizeFilter))
    63  
    64  	Heading1 = bbcode.NewTag("h1", []byte("<h1>"), []byte("</h1>"))
    65  	Heading2 = bbcode.NewTag("h2", []byte("<h2>"), []byte("</h2>"))
    66  	Heading3 = bbcode.NewTag("h3", []byte("<h3>"), []byte("</h3>"))
    67  	Heading4 = bbcode.NewTag("h4", []byte("<h4>"), []byte("</h4>"))
    68  	Heading5 = bbcode.NewTag("h5", []byte("<h5>"), []byte("</h5>"))
    69  	Heading6 = bbcode.NewTag("h6", []byte("<h6>"), []byte("</h6>"))
    70  	Heading7 = bbcode.NewTag("h7", []byte("<h7>"), []byte("</h7>"))
    71  
    72  	Quote = bbcode.NewAttributeTag("quote", []byte("<fieldset class=\"quote\">"), []byte("<blockquote>"), []byte("<legend>"), []byte("</legend>"), []byte("</blockquote></fieldset>"), bbcode.AttrFilterFunc(notEmptyFilter))
    73  
    74  	Code  code
    75  	Image img
    76  	List  list
    77  	Table table
    78  	URL   url
    79  )
    80  
    81  func alignFilter(attr string) []byte {
    82  	switch strings.ToLower(attr) {
    83  	case "left":
    84  		return alignLeft
    85  	case "center", "centre":
    86  		return alignCentre
    87  	case "right":
    88  		return alignRight
    89  	case "full", "justify", "fulljustify", "full-justify", "full justify":
    90  		return alignFull
    91  	}
    92  	return nil
    93  }
    94  
    95  func sizeFilter(attr string) []byte {
    96  	n, _ := strconv.Atoi(attr)
    97  	if n >= 1 && n <= 50 {
    98  		return []byte(attr)
    99  	}
   100  	return nil
   101  }
   102  
   103  func notEmptyFilter(attr string) []byte {
   104  	if len(attr) == 0 {
   105  		return nil
   106  	} else if !strings.ContainsAny(attr, "'\"&<>\000") {
   107  		return []byte(attr)
   108  	}
   109  	var b bytes.Buffer
   110  	template.HTMLEscape(&b, []byte(attr))
   111  	return b.Bytes()
   112  }
   113