pulumi/pkg/util/mapper/object.go
2017-03-14 19:26:14 -07:00

58 lines
2 KiB
Go

// Copyright 2017 Pulumi, Inc. All rights reserved.
package mapper
import (
"reflect"
)
// Value is a "JSON-like" value.
type Value interface{}
// Object is a "JSON-like" object map.
type Object map[string]interface{}
// Array is a "JSON-like" array of values.
type Array []interface{}
// AsObject attempts to coerce an existing value to an object map, returning a non-nil error if it cannot be done.
func AsObject(v interface{}, ty reflect.Type, key string) (*Object, FieldError) {
if vmap, ok := v.(map[string]interface{}); ok {
vobj := Object(vmap)
return &vobj, nil
}
return nil, NewWrongTypeErr(
ty, key, reflect.TypeOf(make(map[string]interface{})), reflect.TypeOf(v))
}
// AsString attempts to coerce an existing value to a string, returning a non-nil error if it cannot be done.
func AsString(v interface{}, ty reflect.Type, key string) (*string, FieldError) {
if s, ok := v.(string); ok {
return &s, nil
}
return nil, NewWrongTypeErr(ty, key, reflect.TypeOf(""), reflect.TypeOf(v))
}
// FieldObject looks up a field by name within an object map, coerces it to an object itself, and returns it. If the
// field exists but is not an object map, or it is missing and optional is false, a non-nil error is returned.
func FieldObject(tree Object, ty reflect.Type, key string, optional bool) (*Object, FieldError) {
if o, has := tree[key]; has {
return AsObject(o, ty, key)
} else if !optional {
// The field doesn't exist and yet it is required; issue an error.
return nil, NewMissingErr(ty, key)
}
return nil, nil
}
// FieldString looks up a field by name within an object map, coerces it to a string, and returns it. If the
// field exists but is not a string, or it is missing and optional is false, a non-nil error is returned.
func FieldString(tree Object, ty reflect.Type, key string, optional bool) (*string, FieldError) {
if s, has := tree[key]; has {
return AsString(s, ty, key)
} else if !optional {
// The field doesn't exist and yet it is required; issue an error.
return nil, NewMissingErr(ty, key)
}
return nil, nil
}