Initial Commit

formparser/parsers.go

@@ -0,0 +1,61 @@
+package formparser
+
+import (
+	"errors"
+	"fmt"
+	"time"
+)
+
+// String parses a string, returning an error if it's outside the range of min,max. It still
+// sets the value so that it can be used for the view model. It would be bad if the user lost
+// a really long page because of the length limit
+func String(value string, target *string, min, max int) error {
+	*target = value
+
+	if len(value) < min || len(value) > max {
+		return fmt.Errorf("not between %d and %d", min, max)
+	}
+
+	return nil
+}
+
+// Select sets the targer if the given form value is inside the list. It will skip if optional
+// is set and the value is empty
+func Select(value string, target *string, allowedValues []string, optional bool) error {
+	if value == "" {
+		if !optional {
+			return errors.New("not a valid option")
+		}
+
+		return nil
+	}
+
+	for _, allowedValue := range allowedValues {
+		if value == allowedValue {
+			*target = value
+			return nil
+		}
+	}
+
+	return errors.New("not a valid option")
+}
+
+// Date parses a date, returning an error if it's missing (and not optional) and if it
+// cannot be parsed according to RFC3339
+func Date(value string, target *time.Time, optional bool) error {
+	if value == "" {
+		if optional {
+			return nil
+		}
+
+		return errors.New("missing")
+	}
+
+	date, err := time.Parse(time.RFC3339, value)
+	if err != nil {
+		return errors.New("an invalid date")
+	}
+
+	*target = date
+	return nil
+}