@@ -2,9 +2,12 @@ package pg
22
33import (
44 "fmt"
5+ "reflect"
6+ "strings"
57
68 "github.com/kataras/iris/v12"
79 "github.com/kataras/iris/v12/x/errors"
10+ "github.com/kataras/iris/v12/x/jsonx"
811
912 "github.com/kataras/pg"
1013 "github.com/kataras/pg/desc"
@@ -23,25 +26,32 @@ import (
2326// - DELETE /{id} - deletes an entity by ID.
2427// The {id} parameter is the entity ID. It can be a string, int, uint, uuid, etc.
2528type EntityController [T any ] struct {
29+ iris.Singleton
30+
2631 repository * pg.Repository [T ]
2732
2833 tableName string
2934 primaryKeyType desc.DataType
3035
36+ disableSchemaRoute bool
37+
3138 // GetID returns the entity ID for GET/{id} and DELETE/{id} paths from the request Context.
3239 GetID func (ctx iris.Context ) any
3340
3441 // ErrorHandler defaults to the PG's error handler. It can be customized for this controller.
3542 // Setting this to nil will panic the application on the first error.
3643 ErrorHandler func (ctx iris.Context , err error ) bool
44+
45+ // AfterPayloadRead is called after the payload is read.
46+ // It can be used to validate the payload or set default fields based on the request Context.
47+ AfterPayloadRead func (ctx iris.Context , payload T ) (T , bool )
3748}
3849
3950// NewEntityController returns a new EntityController[T].
4051// The T is the entity type (e.g. a custom type, Customer).
4152//
4253// Read the type's documentation for more information.
4354func NewEntityController [T any ](middleware * PG ) * EntityController [T ] {
44-
4555 repo := pg.NewRepository [T ](middleware .GetDB ())
4656 errorHandler := middleware .opts .handleError
4757
@@ -51,16 +61,21 @@ func NewEntityController[T any](middleware *PG) *EntityController[T] {
5161 panic (fmt .Sprintf ("pg: entity %s does not have a primary key" , td .Name ))
5262 }
5363
54- return & EntityController [T ]{
64+ controller := & EntityController [T ]{
5565 repository : repo ,
5666 tableName : td .Name ,
5767 primaryKeyType : primaryKey .Type ,
5868 ErrorHandler : errorHandler ,
5969 }
70+
71+ return controller
6072}
6173
62- // Singleton returns true as this controller is a singleton.
63- func (c * EntityController [T ]) Singleton () bool { return true }
74+ // WithoutSchemaRoute disables the GET /schema route.
75+ func (c * EntityController [T ]) WithoutSchemaRoute () * EntityController [T ] {
76+ c .disableSchemaRoute = true
77+ return c
78+ }
6479
6580// Configure registers the controller's routes.
6681// It is called automatically by the Iris API Builder when registered to the Iris Application.
@@ -92,6 +107,11 @@ func (c *EntityController[T]) Configure(r iris.Party) {
92107 }
93108 }
94109
110+ if ! c .disableSchemaRoute {
111+ jsonSchema := newJSONSchema [T ](c .repository .Table ())
112+ r .Get ("/schema" , c .getSchema (jsonSchema ))
113+ }
114+
95115 r .Post ("/" , c .create )
96116 r .Put ("/" , c .update )
97117 r .Get (idParam , c .get )
@@ -112,13 +132,125 @@ func (c *EntityController[T]) readPayload(ctx iris.Context) (T, bool) {
112132 var payload T
113133 err := ctx .ReadJSON (& payload )
114134 if err != nil {
115- errors .InvalidArgument .Details (ctx , "unable to parse body" , err .Error ())
135+ if vErrs , ok := errors .AsValidationErrors (err ); ok {
136+ errors .InvalidArgument .Data (ctx , "validation failure" , vErrs )
137+ } else {
138+ errors .InvalidArgument .Details (ctx , "unable to parse body" , err .Error ())
139+ }
116140 return payload , false
117141 }
118142
143+ if c .AfterPayloadRead != nil {
144+ return c .AfterPayloadRead (ctx , payload )
145+ }
146+
119147 return payload , true
120148}
121149
150+ type jsonSchema [T any ] struct {
151+ Description string `json:"description,omitempty"`
152+ Types []jsonSchemaFieldType `json:"types,omitempty"`
153+ Fields []jsonSchemaField `json:"fields"`
154+ }
155+
156+ type jsonSchemaFieldType struct {
157+ Type string `json:"type"`
158+ Examples []string `json:"examples,omitempty"`
159+ }
160+
161+ type jsonSchemaField struct {
162+ Name string `json:"name"`
163+ Description string `json:"description,omitempty"`
164+ Type string `json:"type"`
165+ DataType string `json:"data_type"`
166+ Required bool `json:"required"`
167+ }
168+
169+ func getJSONTag (v interface {}, fieldIndex []int ) (string , bool ) {
170+ t := reflect .TypeOf (v )
171+ f := t .FieldByIndex (fieldIndex )
172+ jsonTag := f .Tag .Get ("json" )
173+ if jsonTag == "" {
174+ return "" , false
175+ }
176+
177+ return strings .Split (jsonTag , "," )[0 ], true
178+ }
179+
180+ func newJSONSchema [T any ](td * desc.Table ) * jsonSchema [T ] {
181+ var fieldTypes []jsonSchemaFieldType
182+ seenFieldTypes := make (map [reflect.Type ]struct {})
183+
184+ var t T
185+ fields := make ([]jsonSchemaField , 0 , len (td .Columns ))
186+ for _ , col := range td .Columns {
187+ fieldName , ok := getJSONTag (t , col .FieldIndex )
188+ if ! ok {
189+ fieldName = col .Name
190+ }
191+
192+ // Get the field type examples.
193+ if _ , seen := seenFieldTypes [col .FieldType ]; ! seen {
194+ seenFieldTypes [col .FieldType ] = struct {}{}
195+
196+ colValue := reflect .New (col .FieldType ).Interface ()
197+ if exampler , ok := colValue .(jsonx.Exampler ); ok {
198+ exampleValues := exampler .ListExamples ()
199+ fieldTypes = append (fieldTypes , jsonSchemaFieldType {
200+ Type : col .FieldType .String (),
201+ Examples : exampleValues ,
202+ })
203+ }
204+
205+ /*
206+ if m, ok := col.FieldType.MethodByName("Examples"); ok {
207+ var returnValues []reflect.Value
208+ if col.FieldType.Kind() == reflect.Ptr {
209+ returnValues = m.Func.Call([]reflect.Value{newColFieldValue})
210+ } else {
211+ returnValues = m.Func.Call([]reflect.Value{newColFieldValue.Elem()})
212+ }
213+
214+ if len(returnValues) > 0 && returnValues[0].CanInterface() {
215+ v := returnValues[0].Interface()
216+ if v != nil {
217+ if exampleValues, ok := v.([]string); ok {
218+ fieldTypes = append(fieldTypes, jsonSchemaFieldType{
219+ Type: col.FieldType.String(),
220+ Examples: exampleValues,
221+ })
222+ }
223+ }
224+ }
225+ }
226+ */
227+ }
228+
229+ field := jsonSchemaField {
230+ // Here we want the json tag name, not the column name.
231+ Name : fieldName ,
232+ Description : col .Description ,
233+ Type : col .FieldType .String (),
234+ DataType : col .Type .String (),
235+ Required : ! col .Nullable ,
236+ }
237+
238+ fields = append (fields , field )
239+ }
240+
241+ return & jsonSchema [T ]{
242+ Description : td .Description ,
243+ Types : fieldTypes ,
244+ Fields : fields ,
245+ }
246+ }
247+
248+ func (c * EntityController [T ]) getSchema (s * jsonSchema [T ]) iris.Handler {
249+ return func (ctx iris.Context ) {
250+ ctx .JSON (s )
251+ }
252+ }
253+
122254type idPayload struct {
123255 ID any `json:"id"`
124256}
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