Sorting

Sorting adds reordering abilities to GORM models and sorts collections.

Register GORM Callbacks

Sorting utilises GORM callbacks to log data, so you will need to register callbacks first:

import (
  "github.com/jinzhu/gorm"
  "github.com/qor/sorting"
)

func main() {
  db, err := gorm.Open("sqlite3", "demo_db")
  sorting.RegisterCallbacks(db)
}

Sort Modes

Sorting two modes which can be applied as anonymous fields in a model.

• Ascending mode:smallest first (sorting.Sorting)
• Descending mode: smallest last (sorting.SortingDESC)

They can be used as follows:

// Ascending mode
type Category struct {
  gorm.Model
  sorting.Sorting // this will register a `position` column to model Category, used to save record's order
}

db.Find(&categories)
// SELECT * FROM categories ORDER BY position;

// Descending mode
type Product struct {
  gorm.Model
  sorting.SortingDESC // this will register a `position` column to model Product, used to save record's order
}

db.Find(&products)
// SELECT * FROM products ORDER BY position DESC;

Reordering

// Move Up
sorting.MoveUp(&db, &product, 1)
// If a record is in positon 5, it will be brought to 4

// Move Down
sorting.MoveDown(&db, &product, 1)
// If a record is in positon 5, it will be brought to 6

// Move To
sorting.MoveTo(&db, &product, 1)
// If a record is in positon 5, it will be brought to 1

Sorting Collections

Sorts a slice of data:

sorter := sorting.SortableCollection{
  PrimaryKeys: []string{"5", "3", "1", "2"}
}

products := []Product{
  {Model: gorm.Model{ID: 1}, Code: "1"},
  {Model: gorm.Model{ID: 2}, Code: "2"},
  {Model: gorm.Model{ID: 3}, Code: "3"},
  {Model: gorm.Model{ID: 3}, Code: "4"},
  {Model: gorm.Model{ID: 3}, Code: "5"},
}

sorter.Sort(products)

products // => []Product{
         //      {Model: gorm.Model{ID: 3}, Code: "5"},
         //      {Model: gorm.Model{ID: 3}, Code: "3"},
         //      {Model: gorm.Model{ID: 1}, Code: "1"},
         //      {Model: gorm.Model{ID: 2}, Code: "2"},
         //      {Model: gorm.Model{ID: 3}, Code: "4"},
         //    }

Sorting GORM-backend Models

After enabling sorting modes for GORM models, QOR Admin will automatically enable the sorting feature for the resource.

Sorting Demo with QOR

Sorting Collections

If you want to make a sortable select_many, collection_edit field, You could add a sorting.SortableCollection field with name: Field's name + 'Sorter'; which is used to save above field's data order. That Field will also be identified as sortable in QOR Admin.

// For model relations
type Product struct {
  gorm.Model
  l10n.Locale
  Collections           []Collection
  CollectionsSorter     sorting.SortableCollection
  ColorVariations       []ColorVariation `l10n:"sync"`
  ColorVariationsSorter sorting.SortableCollection
}

// For virtual arguments
type selectedProductsArgument struct {
  Products       []string
  ProductsSorter sorting.SortableCollection
}

selectedProductsResource := Admin.NewResource(&selectedProductsArgument{})
selectedProductsResource.Meta(&admin.Meta{Name: "Products", Type: "select_many", Collection: func(value interface{}, context *qor.Context) [][]string {
  var collectionValues [][]string
  var products []*models.Product
  db.DB.Find(&products)
  for _, product := range products {
    collectionValues = append(collectionValues, []string{fmt.Sprint(product.ID), product.Name})
  }
  return collectionValues
}})

Widgets.RegisterWidget(&widget.Widget{
  Name:      "Products",
  Templates: []string{"products"},
  Setting:   selectedProductsResource,
}

About record with composite primary key.

It do support sorting records with composite primary key. However there is a exception, the version_name is a "reserved" primary key for the qor/publish2 support. So DO NOT use version_name as a part of the composite primary key unless you are using qor/publish2.

License

Released under the MIT License.