diff --git a/generator/generator.go b/generator/generator.go
index b3e080529..da641244d 100644
--- a/generator/generator.go
+++ b/generator/generator.go
@@ -1113,6 +1113,12 @@ func (g *generator) writeAttributesCSS(indentLevel int, attrs []parser.Attribute
if err != nil {
return err
}
+ for _, elseIf := range cattr.ElseIfs {
+ err = g.writeAttributesCSS(indentLevel, elseIf.Then)
+ if err != nil {
+ return err
+ }
+ }
err = g.writeAttributesCSS(indentLevel, cattr.Else)
if err != nil {
return err
@@ -1160,6 +1166,11 @@ func getAttributeScripts(attr parser.Attribute) (scripts []string) {
for _, attr := range attr.Then {
scripts = append(scripts, getAttributeScripts(attr)...)
}
+ for _, elseIf := range attr.ElseIfs {
+ for _, attr := range elseIf.Then {
+ scripts = append(scripts, getAttributeScripts(attr)...)
+ }
+ }
for _, attr := range attr.Else {
scripts = append(scripts, getAttributeScripts(attr)...)
}
@@ -1468,6 +1479,26 @@ func (g *generator) writeConditionalAttribute(indentLevel int, elementName strin
}
indentLevel--
}
+ for _, elseIf := range attr.ElseIfs {
+ // } else if x == y {
+ if _, err = g.w.WriteIndent(indentLevel, `} else if `); err != nil {
+ return err
+ }
+ if r, err = g.w.Write(elseIf.Expression.Value); err != nil {
+ return err
+ }
+ g.sourceMap.Add(elseIf.Expression, r)
+ if _, err = g.w.Write(` {` + "\n"); err != nil {
+ return err
+ }
+ {
+ indentLevel++
+ if err = g.writeElementAttributes(indentLevel, elementName, elseIf.Then); err != nil {
+ return err
+ }
+ indentLevel--
+ }
+ }
if len(attr.Else) > 0 {
// } else {
if _, err = g.w.WriteIndent(indentLevel, `} else {`+"\n"); err != nil {
diff --git a/generator/generator_test.go b/generator/generator_test.go
index 74754a19e..0225b380c 100644
--- a/generator/generator_test.go
+++ b/generator/generator_test.go
@@ -2,6 +2,7 @@ package generator
import (
"bytes"
+ "strings"
"testing"
"github.com/a-h/templ/parser/v2"
@@ -71,6 +72,58 @@ templ Hello(name string) {
}
}
+func TestWriteConditionalAttributeElseIf(t *testing.T) {
+ w := new(bytes.Buffer)
+ g := generator{
+ w: NewRangeWriter(w),
+ sourceMap: parser.NewSourceMap(),
+ }
+ attr := &parser.ConditionalAttribute{
+ Expression: parser.Expression{Value: "a"},
+ Then: []parser.Attribute{
+ &parser.ConstantAttribute{
+ Key: parser.ConstantAttributeKey{Name: "class"},
+ Value: "then",
+ },
+ },
+ ElseIfs: []parser.ConditionalElseIfAttribute{
+ {
+ Expression: parser.Expression{Value: "b"},
+ Then: []parser.Attribute{
+ &parser.ConstantAttribute{
+ Key: parser.ConstantAttributeKey{Name: "class"},
+ Value: "else-if",
+ },
+ },
+ },
+ },
+ Else: []parser.Attribute{
+ &parser.ConstantAttribute{
+ Key: parser.ConstantAttributeKey{Name: "class"},
+ Value: "else",
+ },
+ },
+ }
+
+ if err := g.writeConditionalAttribute(0, "div", attr); err != nil {
+ t.Fatalf("failed to write conditional attribute: %v", err)
+ }
+
+ output := w.String()
+ for _, expected := range []string{
+ "if a {\n",
+ "} else if b {\n",
+ "} else {\n",
+ `" class=\"then\""`,
+ `" class=\"else-if\""`,
+ `" class=\"else\""`,
+ } {
+ if !strings.Contains(output, expected) {
+ t.Errorf("expected generated output to contain %q, got:\n%s", expected, output)
+ }
+ }
+}
+
func TestIsTrailingSpaceNeeded(t *testing.T) {
inlineText := &parser.Text{Value: "hello", TrailingSpace: parser.SpaceHorizontal}
newlineText := &parser.Text{Value: "hello", TrailingSpace: parser.SpaceVertical}
diff --git a/internal/format/attributes_test.go b/internal/format/attributes_test.go
index fcc9376e0..e1e904e67 100644
--- a/internal/format/attributes_test.go
+++ b/internal/format/attributes_test.go
@@ -202,6 +202,16 @@ func TestAttributes(t *testing.T) {
Value: "then-class",
},
},
+ ElseIfs: []parser.ConditionalElseIfAttribute{
+ {
+ Then: []parser.Attribute{
+ &parser.ConstantAttribute{
+ Key: parser.ConstantAttributeKey{Name: "class"},
+ Value: "else-if-class",
+ },
+ },
+ },
+ },
Else: []parser.Attribute{
&parser.ConstantAttribute{
Key: parser.ConstantAttributeKey{Name: "class"},
@@ -217,10 +227,14 @@ func TestAttributes(t *testing.T) {
t.Helper()
cond := children[0].(*parser.Element).Attributes[0].(*parser.ConditionalAttribute)
thenAttr := cond.Then[0].(*parser.ConstantAttribute)
+ elseIfAttr := cond.ElseIfs[0].Then[0].(*parser.ConstantAttribute)
elseAttr := cond.Else[0].(*parser.ConstantAttribute)
if thenAttr.Value != "then-class" {
t.Errorf("then branch: got %q, expected %q", thenAttr.Value, "then-class")
}
+ if elseIfAttr.Value != "else-if-class" {
+ t.Errorf("else if branch: got %q, expected %q", elseIfAttr.Value, "else-if-class")
+ }
if elseAttr.Value != "else-class" {
t.Errorf("else branch: got %q, expected %q", elseAttr.Value, "else-class")
}
diff --git a/parser/v2/conditionalattributeparser.go b/parser/v2/conditionalattributeparser.go
index 3ce6b396f..2c11f81f2 100644
--- a/parser/v2/conditionalattributeparser.go
+++ b/parser/v2/conditionalattributeparser.go
@@ -49,7 +49,12 @@ func (conditionalAttributeParser) Parse(pi *parse.Input) (r *ConditionalAttribut
return
}
- // Read the optional 'Else' Nodes.
+ // Read the optional 'ElseIf' attributes.
+ if r.ElseIfs, _, err = parse.ZeroOrMore(attributeElseIfExpression).Parse(pi); err != nil {
+ return
+ }
+
+ // Read the optional 'Else' attributes.
if r.Else, ok, err = attributeElseExpression.Parse(pi); err != nil {
return
}
@@ -71,6 +76,50 @@ func (conditionalAttributeParser) Parse(pi *parse.Input) (r *ConditionalAttribut
return r, true, nil
}
+var attributeElseIfExpression parse.Parser[ConditionalElseIfAttribute] = attributeElseIfExpressionParser{}
+
+type attributeElseIfExpressionParser struct{}
+
+func (attributeElseIfExpressionParser) Parse(pi *parse.Input) (r ConditionalElseIfAttribute, matched bool, err error) {
+ start := pi.Index()
+
+ // Check the prefix first.
+ if _, matched, err = parse.All(parse.OptionalWhitespace, closeBrace, parse.OptionalWhitespace, parse.String("else if")).Parse(pi); err != nil || !matched {
+ pi.Seek(start)
+ return
+ }
+
+ // Rewind to the start of the `if` statement.
+ pi.Seek(pi.Index() - 2)
+ // Parse the Go if expression.
+ if r.Expression, err = parseGo("attribute else if", pi, goexpression.If); err != nil {
+ return
+ }
+
+ // Eat " {".
+ if _, matched, err = openBraceWithOptionalPadding.Parse(pi); err != nil || !matched {
+ err = parse.Error("attribute else if: unterminated (missing closing '{\n')", pi.PositionAt(start))
+ return
+ }
+ if _, _, err = parse.OptionalWhitespace.Parse(pi); err != nil {
+ return
+ }
+
+ // Read the 'Then' attributes.
+ if r.Then, matched, err = (attributesParser{}).Parse(pi); err != nil || !matched {
+ err = parse.Error("attribute if: expected attributes in else if block, but none were found", pi.Position())
+ return
+ }
+
+ if len(r.Then) == 0 {
+ err = parse.Error("attribute if: invalid content or no attributes were found in the else if block", pi.Position())
+ return
+ }
+
+ r.Range = NewRange(pi.PositionAt(start), pi.Position())
+ return r, true, nil
+}
+
var attributeElseExpression parse.Parser[[]Attribute] = attributeElseExpressionParser{}
type attributeElseExpressionParser struct{}
diff --git a/parser/v2/elementparser_test.go b/parser/v2/elementparser_test.go
index 72f455986..7bccaabd2 100644
--- a/parser/v2/elementparser_test.go
+++ b/parser/v2/elementparser_test.go
@@ -2845,6 +2845,52 @@ func TestElementFormatting(t *testing.T) {
input: ``,
expected: ``,
},
+ {
+ name: "conditional attribute else if is formatted on one line",
+ input: ``,
+ expected: ``,
+ },
+ {
+ name: "conditional attribute multiple else if branches are formatted on one line",
+ input: ``,
+ expected: ``,
+ },
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
@@ -2866,3 +2912,51 @@ func TestElementFormatting(t *testing.T) {
})
}
}
+
+func TestConditionalAttributeElseIfsParseAsBranches(t *testing.T) {
+ input := ``
+
+ result, matched, err := element.Parse(parse.NewInput(input))
+ if err != nil {
+ t.Fatalf("parser error: %v", err)
+ }
+ if !matched {
+ t.Fatal("failed to parse element")
+ }
+ el, ok := result.(*Element)
+ if !ok {
+ t.Fatalf("expected Element, got %T", result)
+ }
+ if len(el.Attributes) != 1 {
+ t.Fatalf("expected 1 attribute, got %d", len(el.Attributes))
+ }
+ attr, ok := el.Attributes[0].(*ConditionalAttribute)
+ if !ok {
+ t.Fatalf("expected ConditionalAttribute, got %T", el.Attributes[0])
+ }
+ if got, want := attr.Expression.Value, "lint.Severity == 0"; got != want {
+ t.Fatalf("initial expression: got %q, want %q", got, want)
+ }
+ if got, want := len(attr.ElseIfs), 2; got != want {
+ t.Fatalf("else if count: got %d, want %d", got, want)
+ }
+ if got, want := attr.ElseIfs[0].Expression.Value, "lint.Severity == 1"; got != want {
+ t.Errorf("first else if expression: got %q, want %q", got, want)
+ }
+ if got, want := attr.ElseIfs[1].Expression.Value, "lint.Severity == 2"; got != want {
+ t.Errorf("second else if expression: got %q, want %q", got, want)
+ }
+ if got, want := len(attr.Else), 1; got != want {
+ t.Fatalf("else attribute count: got %d, want %d", got, want)
+ }
+}
diff --git a/parser/v2/types.go b/parser/v2/types.go
index 4c268930c..949ea8ff1 100644
--- a/parser/v2/types.go
+++ b/parser/v2/types.go
@@ -1054,10 +1054,17 @@ func (sa *SpreadAttributes) Copy() Attribute {
type ConditionalAttribute struct {
Expression Expression
Then []Attribute
+ ElseIfs []ConditionalElseIfAttribute
Else []Attribute
Range Range
}
+type ConditionalElseIfAttribute struct {
+ Expression Expression
+ Then []Attribute
+ Range Range
+}
+
func (ca *ConditionalAttribute) String() string {
sb := new(strings.Builder)
_ = ca.Write(sb, 0)
@@ -1065,24 +1072,23 @@ func (ca *ConditionalAttribute) String() string {
}
func (ca *ConditionalAttribute) Write(w io.Writer, indent int) error {
- if err := writeIndent(w, indent, "if "); err != nil {
- return err
- }
- if _, err := w.Write([]byte(ca.Expression.Value)); err != nil {
- return err
- }
- if _, err := w.Write([]byte(" {\n")); err != nil {
+ if err := writeIndent(w, indent, "if ", ca.Expression.Value, " {\n"); err != nil {
return err
}
{
indent++
- for _, attr := range ca.Then {
- if err := attr.Write(w, indent); err != nil {
- return err
- }
- if _, err := w.Write([]byte("\n")); err != nil {
- return err
- }
+ if err := writeAttributesIndented(w, indent, ca.Then); err != nil {
+ return err
+ }
+ indent--
+ }
+ for _, elseIf := range ca.ElseIfs {
+ if err := writeIndent(w, indent, "} else if ", elseIf.Expression.Value, " {\n"); err != nil {
+ return err
+ }
+ indent++
+ if err := writeAttributesIndented(w, indent, elseIf.Then); err != nil {
+ return err
}
indent--
}
@@ -1098,13 +1104,8 @@ func (ca *ConditionalAttribute) Write(w io.Writer, indent int) error {
}
{
indent++
- for _, attr := range ca.Else {
- if err := attr.Write(w, indent); err != nil {
- return err
- }
- if _, err := w.Write([]byte("\n")); err != nil {
- return err
- }
+ if err := writeAttributesIndented(w, indent, ca.Else); err != nil {
+ return err
}
indent--
}
@@ -1114,14 +1115,35 @@ func (ca *ConditionalAttribute) Write(w io.Writer, indent int) error {
return nil
}
+func writeAttributesIndented(w io.Writer, indent int, attrs []Attribute) error {
+ for _, attr := range attrs {
+ if err := attr.Write(w, indent); err != nil {
+ return err
+ }
+ if _, err := w.Write([]byte("\n")); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
func (ca *ConditionalAttribute) Visit(v Visitor) error {
return v.VisitConditionalAttribute(ca)
}
func (ca *ConditionalAttribute) Copy() Attribute {
+ elseIfs := make([]ConditionalElseIfAttribute, len(ca.ElseIfs))
+ for i, elseIf := range ca.ElseIfs {
+ elseIfs[i] = ConditionalElseIfAttribute{
+ Expression: elseIf.Expression,
+ Then: CopyAttributes(elseIf.Then),
+ Range: elseIf.Range,
+ }
+ }
return &ConditionalAttribute{
Expression: ca.Expression,
Then: CopyAttributes(ca.Then),
+ ElseIfs: elseIfs,
Else: CopyAttributes(ca.Else),
Range: ca.Range,
}
diff --git a/parser/v2/visitor/visitor.go b/parser/v2/visitor/visitor.go
index 51a209a9f..1b0682c44 100644
--- a/parser/v2/visitor/visitor.go
+++ b/parser/v2/visitor/visitor.go
@@ -114,6 +114,13 @@ func New() *Visitor {
return err
}
}
+ for _, elseIf := range n.ElseIfs {
+ for _, child := range elseIf.Then {
+ if err := child.Visit(v); err != nil {
+ return err
+ }
+ }
+ }
for _, child := range n.Else {
if err := child.Visit(v); err != nil {
return err