dyno
Package dyno is a utility to work with dynamic objects at ease.
Primary goal is to easily handle dynamic objects and arrays (and a mixture of these)
that are the result of unmarshaling a JSON or YAML text into an interface{}
for example. When unmarshaling into interface{}, libraries usually choose
either map[string]interface{} or map[interface{}]interface{} to represent objects,
and []interface{} to represent arrays. Package dyno supports a mixture of
these in any depth and combination.
When operating on a dynamic object, you designate a value you're interested
in by specifying a path. A path is a navigation; it is a series of map keys
and int slice indices that tells how to get to the value.
Should you need to marshal a dynamic object to JSON which contains maps with
interface{} key type (which is not supported by encoding/json), you may use
the ConvertMapI2MapS converter function.
The implementation does not use reflection at all, so performance is rather good.
Supported Operations
-
Get a (typed) value denoted by a path: Get, GetInt, GetString, GetSlice, GetMapI, GetMapS
-
Get a typed value with built-in conversion / parsing: GetInteger, GetFloating, GetBoolean
-
Specialized get for maps with
stringkeys: SGet -
Set a value denoted by a path: Set
-
Specialized set for maps with
stringkeys: SSet -
Append value(s) to a slice denoted by a path: Append, AppendMore
-
Delete a key from a map or an element from a slice denoted by a path: Delete
-
Convert maps with
interface{}keys to maps withstringkeys: ConvertMapI2MapS
Example
Let's see a simple example editing a JSON text to mask out a password. This is
a simplified version of the Example_jsonEdit example function:
src := `{"login":{"password":"secret","user":"bob"},"name":"cmpA"}`
var v interface{}
if err := json.Unmarshal([]byte(src), &v); err != nil {
panic(err)
}
// Edit (mask out) password:
if err = dyno.Set(v, "xxx", "login", "password"); err != nil {
fmt.Printf("Failed to set password: %v\n", err)
}
edited, err := json.Marshal(v)
fmt.Printf("Edited JSON: %s, error: %v\n", edited, err)
Output will be:
Edited JSON: {"login":{"password":"xxx","user":"bob"},"name":"cmpA"}, error: <nil>