go-rel/changeset

Changeset for Golang

changeset

Changeset mutator for REL. Changesets allow filtering, casting, validation and definition of constraints when manipulating structs.

Install

go get github.com/go-rel/changeset

Example

package main

import (
	"time"

	"github.com/go-rel/rel"
	"github.com/go-rel/rel/adapter/mysql"
	"github.com/go-rel/changeset"
	"github.com/go-rel/changeset/params"
)

type Product struct {
	ID        int
	Name      string
	Price     int
	CreatedAt time.Time
	UpdatedAt time.Time
}

// ChangeProduct prepares data before database operation.
// Such as casting value to appropriate types and perform validations.
func ChangeProduct(product interface{}, params params.Params) *changeset.Changeset {
	ch := changeset.Cast(product, params, []string{"name", "price"})
	changeset.ValidateRequired(ch, []string{"name", "price"})
	changeset.ValidateMin(ch, "price", 100)
	return ch
}

func main() {
    // initialize mysql adapter.
    adapter, _ := mysql.Open(dsn)
    defer adapter.Close()

    // initialize rel's repo.
    repo := rel.New(adapter)

	var product Product

	// Inserting Products.
	// Changeset is used when creating or updating your data.
	ch := ChangeProduct(product, params.Map{
		"name":  "shampoo",
		"price": 1000,
	})

	if ch.Error() != nil {
		// handle error
	}

	// Changeset can also be created directly from json string.
	jsonch := ChangeProduct(product, params.ParseJSON(`{
		"name":  "soap",
		"price": 2000,
	}`))

	// Create products with changeset and return the result to &product,
	if err := repo.Insert(context.TODO(), &product, ch); err != nil {
		// handle error
	}
}

License

Released under the MIT License

changeset's Issues

Changeset apply function ignores non-serial primary field during insertion

Hi!
It seems that changeset struct only accepts the serial primary keys. In case of setting a custom primary key, it never gets inserted:

changeset/changeset.go

Line 90 in c1cf357

if field != pField && scannable(c.types[field]) {

To reproduce:

1. create the table with string primary key
2. create changeset which in case of primary key, generates its value
3. try to insert the new record with changeset mutator

Expected behaviour:
For non-serial primary keys and insertion operation, primary filed should not be ignored and applied as a mutation.

For me just removing this check worked, however, I think that a more sophisticated logic should be applied (the value should not be mutated during update and serial primary key should not applied same way).