html: Rewrite (#23)

html/element.go

@@ -0,0 +1,120 @@
+package html
+
+import (
+	"fmt"
+	"slices"
+	"strings"
+)
+
+var _ HTMLer = new(Element)
+
+type Element struct {
+	tag     string
+	attrs   map[string]string
+	content HTML
+}
+
+func (e *Element) Attribute(name, value string) *Element {
+	e.attrs[name] = value
+	return e
+}
+
+func (e *Element) Class(class ...string) *Element {
+	return e.Attribute("class", strings.Join(class, " "))
+}
+
+func (e *Element) Href(href string) *Element {
+	return e.Attribute("href", href)
+}
+
+func (e *Element) Src(src string) *Element {
+	return e.Attribute("src", src)
+}
+
+func (e *Element) Style(style string) *Element {
+	return e.Attribute("style", style)
+}
+
+func content(v any) HTML {
+	switch v := v.(type) {
+	case nil:
+		return ""
+	case HTML:
+		return v
+	case HTMLer:
+		return v.HTML()
+	case string:
+		return HTML(EscapeString(v))
+	default:
+		return HTML(EscapeString(fmt.Sprint(v)))
+	}
+}
+
+func (e *Element) Content(v any) *Element {
+	e.content = content(v)
+	return e
+}
+
+func (e *Element) AppendContent(v any) *Element {
+	e.content += content(v)
+	return e
+}
+
+func (e *Element) AppendChild(child *Element) *Element {
+	return e.AppendContent(child)
+}
+
+// https://developer.mozilla.org/en-US/docs/Glossary/Void_element
+func (e Element) isVoidElement() bool {
+	return slices.Contains([]string{
+		"area",
+		"base",
+		"br",
+		"col",
+		"embed",
+		"hr",
+		"img",
+		"input",
+		"link",
+		"meta",
+		"param",
+		"source",
+		"track",
+		"wbr",
+	}, strings.ToLower(e.tag))
+}
+
+// https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes
+func (e Element) printAttrs() string {
+	var s []string
+	for k, v := range e.attrs {
+		if v == "" || v == "true" {
+			s = append(s, k)
+		} else if v == "false" {
+			continue
+		} else {
+			s = append(s, fmt.Sprintf("%s=%q", k, v))
+		}
+	}
+	slices.Sort(s)
+	return strings.Join(s, " ")
+}
+
+func (e *Element) HTML() HTML {
+	var b strings.Builder
+	fmt.Fprint(&b, "<", e.tag)
+	if attrs := e.printAttrs(); attrs != "" {
+		fmt.Fprint(&b, " ", attrs)
+	}
+	if e.isVoidElement() {
+		fmt.Fprint(&b, ">")
+	} else {
+		fmt.Fprint(&b, ">", e.content)
+		fmt.Fprintf(&b, "</%s>", e.tag)
+	}
+	return HTML(b.String())
+}
+
+func NewElement(tag string) *Element {
+	return &Element{tag, make(map[string]string), ""}
+}

html/element_test.go

@@ -0,0 +1,44 @@
+package html
+
+import "testing"
+
+func TestElement(t *testing.T) {
+	for _, tc := range []struct {
+		tag     string
+		attrs   [][2]string
+		content string
+		html    HTML
+	}{
+		{"a", [][2]string{{"href", "/"}, {"style", "display:none"}}, "test", `<a href="/" style="display:none">test</a>`},
+		{"p", nil, "test", "<p>test</p>"},
+		{"p", [][2]string{{"hidden", "true"}}, "test", "<p hidden>test</p>"},
+		{"p", [][2]string{{"hidden", "false"}}, "test", "<p>test</p>"},
+		{"div", nil, "<test>", "<div>&lt;test&gt;</div>"},
+	} {
+		e := NewElement(tc.tag).Content(tc.content)
+		for _, i := range tc.attrs {
+			e.Attribute(i[0], i[1])
+		}
+		if res := e.HTML(); tc.html != res {
+			t.Errorf("expected %q; got %q", tc.html, res)
+		}
+	}
+	if div, expect := Div().Content(Br()).HTML(), "<div><br></div>"; expect != string(div) {
+		t.Errorf("expected %q; got %q", expect, div)
+	}
+}
+
+func TestAppend(t *testing.T) {
+	e := Div()
+	if expect := "<div></div>"; expect != string(e.HTML()) {
+		t.Errorf("expected %q; got %q", expect, e.HTML())
+	}
+	e.AppendContent("test")
+	if expect := "<div>test</div>"; expect != string(e.HTML()) {
+		t.Errorf("expected %q; got %q", expect, e.HTML())
+	}
+	e.AppendChild(Img().Src("test"))
+	if expect := `<div>test<img src="test"></div>`; expect != string(e.HTML()) {
+		t.Errorf("expected %q; got %q", expect, e.HTML())
+	}
+}

html/html.go

@@ -1,53 +1,36 @@
 package html
 
-import (
-	"fmt"
-	"html"
-	"strings"
-)
+import "html"
 
 var (
 	EscapeString   = html.EscapeString
 	UnescapeString = html.UnescapeString
 )
 
-type Attribute struct {
-	Name  string
-	Value string
-}
-
-func Attributes(pairs ...string) (attributes []Attribute) {
-	if len(pairs)%2 != 0 {
-		panic("pairs must have even number of elements")
-	}
-	for i := 0; i < len(pairs); i = i + 2 {
-		attributes = append(attributes, Attribute{pairs[i], pairs[i+1]})
-	}
-	return
-}
-
-func (attr Attribute) String() string {
-	if attr.Value == "" || attr.Value == "true" {
-		return attr.Name
-	}
-	return fmt.Sprintf("%s=%q", attr.Name, attr.Value)
-}
-
 type HTML string
 
-func Element[T HTML | string](tag string, attributes []Attribute, content T) HTML {
-	var b strings.Builder
-	fmt.Fprint(&b, "<", tag)
-	for _, i := range attributes {
-		fmt.Fprint(&b, " ", i)
-	}
-	fmt.Fprint(&b, ">")
-	switch any(content).(type) {
-	case HTML:
-		fmt.Fprint(&b, content)
-	default:
-		fmt.Fprint(&b, EscapeString(string(content)))
-	}
-	fmt.Fprintf(&b, "</%s>", tag)
-	return HTML(b.String())
+type HTMLer interface {
+	HTML() HTML
 }
+
+func A() *Element     { return NewElement("a") }
+func B() *Element     { return NewElement("b") }
+func Br() *Element    { return NewElement("br") }
+func Div() *Element   { return NewElement("div") }
+func Em() *Element    { return NewElement("em") }
+func Form() *Element  { return NewElement("form") }
+func H1() *Element    { return NewElement("h1") }
+func H2() *Element    { return NewElement("h2") }
+func I() *Element     { return NewElement("i") }
+func Img() *Element   { return NewElement("img") }
+func Input() *Element { return NewElement("input") }
+func Label() *Element { return NewElement("label") }
+func Li() *Element    { return NewElement("li") }
+func P() *Element     { return NewElement("p") }
+func Span() *Element  { return NewElement("span") }
+func Svg() *Element   { return NewElement("svg") }
+func Table() *Element { return NewElement("table") }
+func Tbody() *Element { return NewElement("tbody") }
+func Title() *Element { return NewElement("title") }
+func Thead() *Element { return NewElement("thead") }
+func Ul() *Element    { return NewElement("ul") }

html/table.go

@@ -0,0 +1,69 @@
+package html
+
+import "strconv"
+
+func Tr[T *TableHeader | *TableData](element ...T) *Element {
+	tr := NewElement("tr")
+	for _, i := range element {
+		tr.AppendContent(i)
+	}
+	return tr
+}
+
+var (
+	_ HTMLer = new(TableHeader)
+	_ HTMLer = new(TableData)
+)
+
+type (
+	TableHeader struct{ *Element }
+	TableData   struct{ *Element }
+)
+
+func Th(content any) *TableHeader {
+	return &TableHeader{NewElement("th").Content(content)}
+}
+
+func (th *TableHeader) Abbr(abbr string) *TableHeader {
+	th.Element.Attribute("abbr", abbr)
+	return th
+}
+
+func (th *TableHeader) Colspan(n uint) *TableHeader {
+	th.Element.Attribute("colspan", strconv.FormatUint(uint64(n), 10))
+	return th
+}
+
+func (th *TableHeader) Headers(headers string) *TableHeader {
+	th.Element.Attribute("headers", headers)
+	return th
+}
+
+func (th *TableHeader) Rowspan(n uint) *TableHeader {
+	th.Element.Attribute("rowspan", strconv.FormatUint(uint64(n), 10))
+	return th
+}
+
+func (th *TableHeader) Scope(scope string) *TableHeader {
+	th.Element.Attribute("scope", scope)
+	return th
+}
+
+func Td(content any) *TableData {
+	return &TableData{NewElement("td").Content(content)}
+}
+
+func (td *TableData) Colspan(n uint) *TableData {
+	td.Element.Attribute("colspan", strconv.FormatUint(uint64(n), 10))
+	return td
+}
+
+func (td *TableData) Headers(headers string) *TableData {
+	td.Element.Attribute("headers", headers)
+	return td
+}
+
+func (td *TableData) Rowspan(n uint) *TableData {
+	td.Element.Attribute("rowspan", strconv.FormatUint(uint64(n), 10))
+	return td
+}

html/table_test.go

@@ -0,0 +1,12 @@
+package html
+
+import "testing"
+
+func TestTable(t *testing.T) {
+	table := `<table><thead><tr><th colspan="2">H1</th><th>H2</th></tr></thead><tbody><tr><td>B1</td><td>B2</td></tr></tbody></table>`
+	if e := Table().
+		AppendChild(Thead().AppendChild(Tr(Th("H1").Colspan(2), Th("H2")))).
+		AppendChild(Tbody().AppendChild(Tr(Td("B1"), Td("B2")))); string(e.HTML()) != table {
+		t.Errorf("expected %q; got %q", table, e.HTML())
+	}
+}