adding auto header for struct

Author: olekukonko

config.go

@@ -688,6 +688,12 @@ func (bb *BehaviorConfigBuilder) WithCompactMerge(state tw.State) *BehaviorConfi
 	return bb
 }
 
+// WithAutoHeader enables/disables automatic header extraction for structs in Bulk.
+func (bb *BehaviorConfigBuilder) WithAutoHeader(state tw.State) *BehaviorConfigBuilder {
+	bb.config.AutoHeader = state
+	return bb
+}
+
 // ColumnConfigBuilder configures column-specific settings
 type ColumnConfigBuilder struct {
 	parent *ConfigBuilder

option.go

@@ -715,8 +715,9 @@ func defaultConfig() Config {
 		},
 		Debug: false,
 		Behavior: tw.Behavior{
-			AutoHide:  tw.Off,
-			TrimSpace: tw.On,
+			AutoHide:   tw.Off,
+			TrimSpace:  tw.On,
+			AutoHeader: tw.Off,
 		},
 	}
 }

tablewriter.go

@@ -219,26 +219,34 @@ func (t *Table) Append(rows ...interface{}) error { // rows is already []interfa
 	return nil
 }
 
-// Bulk adds multiple rows from a slice to the table (legacy method).
-// Parameter rows must be a slice compatible with stringer or []string.
-// Returns an error if the input is invalid or appending fails.
+// Bulk adds multiple rows from a slice to the table.
+// If Behavior.AutoHeader is enabled, no headers set, and rows is a slice of structs,
+// automatically extracts/sets headers from the first struct.
 func (t *Table) Bulk(rows interface{}) error {
-	t.logger.Debug("Starting Bulk operation")
 	rv := reflect.ValueOf(rows)
 	if rv.Kind() != reflect.Slice {
-		err := errors.Newf("Bulk expects a slice, got %T", rows)
-		t.logger.Debugf("Bulk error: %v", err)
-		return err
+		return errors.Newf("Bulk expects a slice, got %T", rows)
+	}
+	if rv.Len() == 0 {
+		return nil
+	}
+
+	if t.config.Behavior.AutoHeader.Enabled() && len(t.headers) == 0 {
+		first := rv.Index(0).Interface()
+		if reflect.TypeOf(first).Kind() == reflect.Struct {
+			headers := t.extractHeadersFromStruct(first)
+			if len(headers) > 0 {
+				t.Header(headers)
+			}
+		}
 	}
+
 	for i := 0; i < rv.Len(); i++ {
 		row := rv.Index(i).Interface()
-		t.logger.Debugf("Processing bulk row %d: %v", i, row)
 		if err := t.appendSingle(row); err != nil {
-			t.logger.Debugf("Bulk append failed at index %d: %v", i, err)
 			return err
 		}
 	}
-	t.logger.Debugf("Bulk completed, processed %d rows", rv.Len())
 	return nil
 }
 

tw/types.go

@@ -152,6 +152,11 @@ type Behavior struct {
 	// Compact enables optimized width calculation for merged cells, such as in horizontal merges,
 	// by systematically determining the most efficient width instead of scaling by the number of columns.
 	Compact Compact
+
+	// AutoHeader automatically extracts and sets headers from struct fields when Bulk is called with a slice of structs.
+	// Uses JSON tags if present, falls back to field names (title-cased). Skips unexported or json:"-" fields.
+	// Enabled by default for convenience.
+	AutoHeader State
 }
 
 // Padding defines the spacing characters around cell content in all four directions.

zoo.go

@@ -1694,3 +1694,34 @@ func (t *Table) updateWidths(row []string, widths tw.Mapper[int, int], padding t
 		}
 	}
 }
+
+// extractHeadersFromStruct generates table headers from a sample struct.
+// Internal: Uses JSON tags if available (splitting on ","), falls back to field name (title-cased).
+// Skips unexported or json:"-" fields.
+func (t *Table) extractHeadersFromStruct(sample interface{}) []string {
+	v := reflect.ValueOf(sample)
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+	if v.Kind() != reflect.Struct {
+		return nil
+	}
+	typ := v.Type()
+	headers := make([]string, 0, typ.NumField())
+	for i := 0; i < typ.NumField(); i++ {
+		field := typ.Field(i)
+		if field.PkgPath != "" { // Unexported
+			continue
+		}
+		jsonTag := field.Tag.Get("json")
+		if jsonTag == "-" {
+			continue
+		}
+		name := field.Name
+		if jsonTag != "" {
+			name = strings.Split(jsonTag, ",")[0]
+		}
+		headers = append(headers, tw.Title(name))
+	}
+	return headers
+}