service/vendor/github.com/ulule/deepcopier/README.md

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2024-06-17 22:25:43 +08:00
# Deepcopier
[![Build Status](https://secure.travis-ci.org/ulule/deepcopier.svg?branch=master)](http://travis-ci.org/ulule/deepcopier)
This package is meant to make copying of structs to/from others structs a bit easier.
## Installation
```bash
go get -u github.com/ulule/deepcopier
```
## Usage
```golang
// Deep copy instance1 into instance2
Copy(instance1).To(instance2)
// Deep copy instance1 into instance2 and passes the following context (which
// is basically a map[string]interface{}) as first argument
// to methods of instance2 that defined the struct tag "context".
Copy(instance1).WithContext(map[string]interface{}{"foo": "bar"}).To(instance2)
// Deep copy instance2 into instance1
Copy(instance1).From(instance2)
// Deep copy instance2 into instance1 and passes the following context (which
// is basically a map[string]interface{}) as first argument
// to methods of instance1 that defined the struct tag "context".
Copy(instance1).WithContext(map[string]interface{}{"foo": "bar"}).From(instance2)
```
Available options for `deepcopier` struct tag:
| Option | Description |
| --------- | -------------------------------------------------------------------- |
| `field` | Field or method name in source instance |
| `skip` | Ignores the field |
| `context` | Takes a `map[string]interface{}` as first argument (for methods) |
| `force` | Set the value of a `sql.Null*` field (instead of copying the struct) |
**Options example:**
```golang
type Source struct {
Name string
SkipMe string
SQLNullStringToSQLNullString sql.NullString
SQLNullStringToString sql.NullString
}
func (Source) MethodThatTakesContext(c map[string]interface{}) string {
return "whatever"
}
type Destination struct {
FieldWithAnotherNameInSource string `deepcopier:"field:Name"`
SkipMe string `deepcopier:"skip"`
MethodThatTakesContext string `deepcopier:"context"`
SQLNullStringToSQLNullString sql.NullString
SQLNullStringToString string `deepcopier:"force"`
}
```
Example:
```golang
package main
import (
"fmt"
"github.com/ulule/deepcopier"
)
// Model
type User struct {
// Basic string field
Name string
// Deepcopier supports https://golang.org/pkg/database/sql/driver/#Valuer
Email sql.NullString
}
func (u *User) MethodThatTakesContext(ctx map[string]interface{}) string {
// do whatever you want
return "hello from this method"
}
// Resource
type UserResource struct {
DisplayName string `deepcopier:"field:Name"`
SkipMe string `deepcopier:"skip"`
MethodThatTakesContext string `deepcopier:"context"`
Email string `deepcopier:"force"`
}
func main() {
user := &User{
Name: "gilles",
Email: sql.NullString{
Valid: true,
String: "gilles@example.com",
},
}
resource := &UserResource{}
deepcopier.Copy(user).To(resource)
fmt.Println(resource.DisplayName)
fmt.Println(resource.Email)
}
```
Looking for more information about the usage?
We wrote [an introduction article](https://github.com/ulule/deepcopier/blob/master/examples/rest-usage/README.rst).
Have a look and feel free to give us your feedback.
## Contributing
* Ping us on twitter [@oibafsellig](https://twitter.com/oibafsellig), [@thoas](https://twitter.com/thoas)
* Fork the [project](https://github.com/ulule/deepcopier)
* Help us improving and fixing [issues](https://github.com/ulule/deepcopier/issues)
Don't hesitate ;)