go-rel/gin-example

package todos

import (
    "context"

    "github.com/go-rel/gin-example/scores"
    "github.com/go-rel/rel"
    "go.uber.org/zap"
)

type update struct {
    repository rel.Repository
    scores     scores.Service
}

func (u update) Update(ctx context.Context, todo *Todo, changes rel.Changeset) error {
    if err := todo.Validate(); err != nil {
        logger.Warn("validation error", zap.Error(err))
        return err
    }

    // update score if completed is changed.
    if changes.FieldChanged("completed") {
        return u.repository.Transaction(ctx, func(ctx context.Context) error {
            u.repository.MustUpdate(ctx, todo, changes)

            if todo.Completed {
                return u.scores.Earn(ctx, "todo completed", 1)
            }

            return u.scores.Earn(ctx, "todo uncompleted", -2)
        })
    }

    u.repository.MustUpdate(ctx, todo, changes)
    return nil
}