support event stream

pkg/utils/api.go

@@ -1,6 +1,7 @@
 package utils
 
 import (
+	"encoding/json"
 	"net/http"
 	"reflect"
 
@@ -80,6 +81,75 @@ func PrintDataErrorResult(c *core.WebContext, contentType string, err *errs.Erro
 	c.Abort()
 }
 
+// SetEventStreamHeader sets the headers for event stream response
+func SetEventStreamHeader(c *core.WebContext) {
+	c.Writer.Header().Set("Content-Type", "text/event-stream")
+	c.Writer.Header().Set("Cache-Control", "no-cache")
+	c.Writer.Header().Set("Connection", "keep-alive")
+}
+
+func WriteEventStreamJsonSuccessResult(c *core.WebContext, result any) {
+	data, err := json.Marshal(result)
+
+	if err != nil {
+		c.Abort()
+		return
+	}
+
+	_, err = c.Writer.WriteString("data: " + string(data) + "\n\n")
+
+	if err != nil {
+		c.Abort()
+		return
+	}
+
+	c.Writer.Flush()
+}
+
+func WriteEventStreamJsonErrorResult(c *core.WebContext, originalErr *errs.Error) {
+	c.SetResponseError(originalErr)
+
+	errorMessage := originalErr.Error()
+
+	if originalErr.Code() == errs.ErrIncompleteOrIncorrectSubmission.Code() && len(originalErr.BaseError) > 0 {
+		validationErrors, ok := originalErr.BaseError[0].(validator.ValidationErrors)
+
+		if ok {
+			for _, err := range validationErrors {
+				errorMessage = getValidationErrorText(err)
+				break
+			}
+		}
+	}
+
+	result := gin.H{
+		"success":      false,
+		"errorCode":    originalErr.Code(),
+		"errorMessage": errorMessage,
+		"path":         c.Request.URL.Path,
+	}
+
+	if originalErr.Context != nil {
+		result["context"] = originalErr.Context
+	}
+
+	data, err := json.Marshal(result)
+
+	if err != nil {
+		c.Abort()
+		return
+	}
+
+	_, err = c.Writer.WriteString("data: " + string(data) + "\n\n")
+
+	if err != nil {
+		c.Abort()
+		return
+	}
+
+	c.Writer.Flush()
+}
+
 func getValidationErrorText(err validator.FieldError) string {
 	fieldName := GetFirstLowerCharString(err.Field())