Add simple filter, add error to creation

Author: Vilsol

filter/simple.go

@@ -0,0 +1,34 @@
+package filter
+
+type Operation string
+
+const (
+	// Equals
+	OpEQ Operation = "eq"
+
+	// Not Equals
+	OpNEQ Operation = "neq"
+
+	// Less Than
+	OpLT Operation = "lt"
+
+	// Less Than or Equals
+	OpLTE Operation = "lte"
+
+	// Greater Than
+	OpGT Operation = "gt"
+
+	// Greater Than or Equals
+	OpGTE Operation = "gte"
+)
+
+type Simple struct {
+	// The key to filter by
+	Key string `json:"key"`
+
+	// The filter operation
+	Operation Operation `json:"op"`
+
+	// The filter value
+	Value interface{} `json:"val"`
+}

plugins/types.go

@@ -60,7 +60,7 @@ type Filter interface {
 	ValidateFilter(filter filter.ProcessedFilter) (bool, error)
 
 	// Create a new instance of the filter
-	CreateFilter(filter string) interface{}
+	CreateFilter(filter string) (interface{}, error)
 }
 
 type Registry interface {