Live: array for Processor, Outputter and Subscriber in channel rule top level (#39677)

pkg/services/live/pipeline/frame_processor_keep_field.go

@@ -0,0 +1,46 @@
+package pipeline
+
+import (
+	"context"
+
+	"github.com/grafana/grafana-plugin-sdk-go/data"
+)
+
+type KeepFieldsFrameProcessorConfig struct {
+	FieldNames []string `json:"fieldNames"`
+}
+
+// KeepFieldsFrameProcessor can keep specified fields in a data.Frame dropping all other fields.
+type KeepFieldsFrameProcessor struct {
+	config KeepFieldsFrameProcessorConfig
+}
+
+func NewKeepFieldsFrameProcessor(config KeepFieldsFrameProcessorConfig) *KeepFieldsFrameProcessor {
+	return &KeepFieldsFrameProcessor{config: config}
+}
+
+func stringInSlice(str string, slice []string) bool {
+	for _, s := range slice {
+		if s == str {
+			return true
+		}
+	}
+	return false
+}
+
+const FrameProcessorTypeKeepFields = "keepFields"
+
+func (p *KeepFieldsFrameProcessor) Type() string {
+	return FrameProcessorTypeKeepFields
+}
+
+func (p *KeepFieldsFrameProcessor) ProcessFrame(_ context.Context, _ Vars, frame *data.Frame) (*data.Frame, error) {
+	var fieldsToKeep []*data.Field
+	for _, field := range frame.Fields {
+		if stringInSlice(field.Name, p.config.FieldNames) {
+			fieldsToKeep = append(fieldsToKeep, field)
+		}
+	}
+	f := data.NewFrame(frame.Name, fieldsToKeep...)
+	return f, nil
+}