540 lines
14 KiB
Go
540 lines
14 KiB
Go
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package jsonapi
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import (
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"encoding/json"
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"errors"
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"fmt"
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"io"
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"reflect"
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"strconv"
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"strings"
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"time"
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)
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var (
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// ErrBadJSONAPIStructTag is returned when the Struct field's JSON API
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// annotation is invalid.
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ErrBadJSONAPIStructTag = errors.New("Bad jsonapi struct tag format")
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// ErrBadJSONAPIID is returned when the Struct JSON API annotated "id" field
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// was not a valid numeric type.
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ErrBadJSONAPIID = errors.New(
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"id should be either string, int(8,16,32,64) or uint(8,16,32,64)")
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// ErrExpectedSlice is returned when a variable or argument was expected to
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// be a slice of *Structs; MarshalMany will return this error when its
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// interface{} argument is invalid.
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ErrExpectedSlice = errors.New("models should be a slice of struct pointers")
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// ErrUnexpectedType is returned when marshalling an interface; the interface
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// had to be a pointer or a slice; otherwise this error is returned.
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ErrUnexpectedType = errors.New("models should be a struct pointer or slice of struct pointers")
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)
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// MarshalPayload writes a jsonapi response for one or many records. The
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// related records are sideloaded into the "included" array. If this method is
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// given a struct pointer as an argument it will serialize in the form
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// "data": {...}. If this method is given a slice of pointers, this method will
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// serialize in the form "data": [...]
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//
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// One Example: you could pass it, w, your http.ResponseWriter, and, models, a
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// ptr to a Blog to be written to the response body:
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//
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// func ShowBlog(w http.ResponseWriter, r *http.Request) {
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// blog := &Blog{}
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//
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// w.Header().Set("Content-Type", jsonapi.MediaType)
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// w.WriteHeader(http.StatusOK)
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//
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// if err := jsonapi.MarshalPayload(w, blog); err != nil {
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// http.Error(w, err.Error(), http.StatusInternalServerError)
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// }
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// }
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//
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// Many Example: you could pass it, w, your http.ResponseWriter, and, models, a
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// slice of Blog struct instance pointers to be written to the response body:
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//
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// func ListBlogs(w http.ResponseWriter, r *http.Request) {
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// blogs := []*Blog{}
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//
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// w.Header().Set("Content-Type", jsonapi.MediaType)
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// w.WriteHeader(http.StatusOK)
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//
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// if err := jsonapi.MarshalPayload(w, blogs); err != nil {
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// http.Error(w, err.Error(), http.StatusInternalServerError)
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// }
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// }
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//
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func MarshalPayload(w io.Writer, models interface{}) error {
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payload, err := Marshal(models)
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if err != nil {
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return err
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}
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if err := json.NewEncoder(w).Encode(payload); err != nil {
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return err
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}
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return nil
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}
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// Marshal does the same as MarshalPayload except it just returns the payload
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// and doesn't write out results. Useful if you use your own JSON rendering
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// library.
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func Marshal(models interface{}) (Payloader, error) {
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switch vals := reflect.ValueOf(models); vals.Kind() {
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case reflect.Slice:
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m, err := convertToSliceInterface(&models)
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if err != nil {
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return nil, err
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}
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payload, err := marshalMany(m)
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if err != nil {
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return nil, err
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}
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if linkableModels, isLinkable := models.(Linkable); isLinkable {
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jl := linkableModels.JSONAPILinks()
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if er := jl.validate(); er != nil {
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return nil, er
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}
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payload.Links = linkableModels.JSONAPILinks()
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}
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if metableModels, ok := models.(Metable); ok {
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payload.Meta = metableModels.JSONAPIMeta()
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}
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return payload, nil
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case reflect.Ptr:
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// Check that the pointer was to a struct
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if reflect.Indirect(vals).Kind() != reflect.Struct {
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return nil, ErrUnexpectedType
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}
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return marshalOne(models)
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default:
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return nil, ErrUnexpectedType
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}
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}
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// MarshalPayloadWithoutIncluded writes a jsonapi response with one or many
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// records, without the related records sideloaded into "included" array.
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// If you want to serialize the relations into the "included" array see
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// MarshalPayload.
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//
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// models interface{} should be either a struct pointer or a slice of struct
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// pointers.
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func MarshalPayloadWithoutIncluded(w io.Writer, model interface{}) error {
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payload, err := Marshal(model)
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if err != nil {
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return err
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}
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payload.clearIncluded()
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if err := json.NewEncoder(w).Encode(payload); err != nil {
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return err
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}
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return nil
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}
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// marshalOne does the same as MarshalOnePayload except it just returns the
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// payload and doesn't write out results. Useful is you use your JSON rendering
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// library.
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func marshalOne(model interface{}) (*OnePayload, error) {
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included := make(map[string]*Node)
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rootNode, err := visitModelNode(model, &included, true)
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if err != nil {
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return nil, err
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}
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payload := &OnePayload{Data: rootNode}
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payload.Included = nodeMapValues(&included)
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return payload, nil
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}
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// marshalMany does the same as MarshalManyPayload except it just returns the
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// payload and doesn't write out results. Useful is you use your JSON rendering
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// library.
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func marshalMany(models []interface{}) (*ManyPayload, error) {
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payload := &ManyPayload{
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Data: []*Node{},
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}
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included := map[string]*Node{}
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for _, model := range models {
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node, err := visitModelNode(model, &included, true)
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if err != nil {
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return nil, err
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}
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payload.Data = append(payload.Data, node)
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}
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payload.Included = nodeMapValues(&included)
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return payload, nil
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}
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// MarshalOnePayloadEmbedded - This method not meant to for use in
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// implementation code, although feel free. The purpose of this
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// method is for use in tests. In most cases, your request
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// payloads for create will be embedded rather than sideloaded for
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// related records. This method will serialize a single struct
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// pointer into an embedded json response. In other words, there
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// will be no, "included", array in the json all relationships will
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// be serailized inline in the data.
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//
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// However, in tests, you may want to construct payloads to post
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// to create methods that are embedded to most closely resemble
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// the payloads that will be produced by the client. This is what
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// this method is intended for.
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//
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// model interface{} should be a pointer to a struct.
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func MarshalOnePayloadEmbedded(w io.Writer, model interface{}) error {
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rootNode, err := visitModelNode(model, nil, false)
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if err != nil {
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return err
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}
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payload := &OnePayload{Data: rootNode}
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if err := json.NewEncoder(w).Encode(payload); err != nil {
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return err
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}
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return nil
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}
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func visitModelNode(model interface{}, included *map[string]*Node,
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sideload bool) (*Node, error) {
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node := new(Node)
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var er error
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value := reflect.ValueOf(model)
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if value.IsNil() {
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return nil, nil
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}
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modelValue := value.Elem()
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modelType := value.Type().Elem()
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for i := 0; i < modelValue.NumField(); i++ {
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structField := modelValue.Type().Field(i)
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tag := structField.Tag.Get(annotationJSONAPI)
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if tag == "" {
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continue
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}
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fieldValue := modelValue.Field(i)
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fieldType := modelType.Field(i)
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args := strings.Split(tag, annotationSeperator)
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if len(args) < 1 {
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er = ErrBadJSONAPIStructTag
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break
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}
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annotation := args[0]
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if (annotation == annotationClientID && len(args) != 1) ||
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(annotation != annotationClientID && len(args) < 2) {
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er = ErrBadJSONAPIStructTag
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break
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}
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if annotation == annotationPrimary {
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v := fieldValue
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// Deal with PTRS
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var kind reflect.Kind
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if fieldValue.Kind() == reflect.Ptr {
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kind = fieldType.Type.Elem().Kind()
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v = reflect.Indirect(fieldValue)
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} else {
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kind = fieldType.Type.Kind()
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}
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// Handle allowed types
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switch kind {
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case reflect.String:
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node.ID = v.Interface().(string)
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case reflect.Int:
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node.ID = strconv.FormatInt(int64(v.Interface().(int)), 10)
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case reflect.Int8:
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node.ID = strconv.FormatInt(int64(v.Interface().(int8)), 10)
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case reflect.Int16:
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node.ID = strconv.FormatInt(int64(v.Interface().(int16)), 10)
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case reflect.Int32:
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node.ID = strconv.FormatInt(int64(v.Interface().(int32)), 10)
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case reflect.Int64:
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node.ID = strconv.FormatInt(v.Interface().(int64), 10)
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case reflect.Uint:
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node.ID = strconv.FormatUint(uint64(v.Interface().(uint)), 10)
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case reflect.Uint8:
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node.ID = strconv.FormatUint(uint64(v.Interface().(uint8)), 10)
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case reflect.Uint16:
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node.ID = strconv.FormatUint(uint64(v.Interface().(uint16)), 10)
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case reflect.Uint32:
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node.ID = strconv.FormatUint(uint64(v.Interface().(uint32)), 10)
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case reflect.Uint64:
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node.ID = strconv.FormatUint(v.Interface().(uint64), 10)
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default:
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// We had a JSON float (numeric), but our field was not one of the
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// allowed numeric types
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er = ErrBadJSONAPIID
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break
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}
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node.Type = args[1]
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} else if annotation == annotationClientID {
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clientID := fieldValue.String()
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if clientID != "" {
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node.ClientID = clientID
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}
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} else if annotation == annotationAttribute {
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var omitEmpty, iso8601 bool
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if len(args) > 2 {
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for _, arg := range args[2:] {
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switch arg {
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case annotationOmitEmpty:
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omitEmpty = true
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case annotationISO8601:
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iso8601 = true
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}
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}
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}
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if node.Attributes == nil {
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node.Attributes = make(map[string]interface{})
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}
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if fieldValue.Type() == reflect.TypeOf(time.Time{}) {
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t := fieldValue.Interface().(time.Time)
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if t.IsZero() {
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continue
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}
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if iso8601 {
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node.Attributes[args[1]] = t.UTC().Format(iso8601TimeFormat)
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} else {
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node.Attributes[args[1]] = t.Unix()
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}
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} else if fieldValue.Type() == reflect.TypeOf(new(time.Time)) {
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// A time pointer may be nil
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if fieldValue.IsNil() {
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if omitEmpty {
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continue
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}
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node.Attributes[args[1]] = nil
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} else {
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tm := fieldValue.Interface().(*time.Time)
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if tm.IsZero() && omitEmpty {
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continue
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}
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if iso8601 {
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node.Attributes[args[1]] = tm.UTC().Format(iso8601TimeFormat)
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} else {
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node.Attributes[args[1]] = tm.Unix()
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}
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}
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} else {
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// Dealing with a fieldValue that is not a time
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emptyValue := reflect.Zero(fieldValue.Type())
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// See if we need to omit this field
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if omitEmpty && reflect.DeepEqual(fieldValue.Interface(), emptyValue.Interface()) {
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continue
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}
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strAttr, ok := fieldValue.Interface().(string)
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if ok {
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node.Attributes[args[1]] = strAttr
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} else {
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node.Attributes[args[1]] = fieldValue.Interface()
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}
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}
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} else if annotation == annotationRelation {
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var omitEmpty bool
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//add support for 'omitempty' struct tag for marshaling as absent
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if len(args) > 2 {
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omitEmpty = args[2] == annotationOmitEmpty
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}
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isSlice := fieldValue.Type().Kind() == reflect.Slice
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if omitEmpty &&
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(isSlice && fieldValue.Len() < 1 ||
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(!isSlice && fieldValue.IsNil())) {
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continue
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}
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if node.Relationships == nil {
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node.Relationships = make(map[string]interface{})
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}
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var relLinks *Links
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if linkableModel, ok := model.(RelationshipLinkable); ok {
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relLinks = linkableModel.JSONAPIRelationshipLinks(args[1])
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}
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var relMeta *Meta
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if metableModel, ok := model.(RelationshipMetable); ok {
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relMeta = metableModel.JSONAPIRelationshipMeta(args[1])
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}
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if isSlice {
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// to-many relationship
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relationship, err := visitModelNodeRelationships(
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fieldValue,
|
||
|
|
included,
|
||
|
|
sideload,
|
||
|
|
)
|
||
|
|
if err != nil {
|
||
|
|
er = err
|
||
|
|
break
|
||
|
|
}
|
||
|
|
relationship.Links = relLinks
|
||
|
|
relationship.Meta = relMeta
|
||
|
|
|
||
|
|
if sideload {
|
||
|
|
shallowNodes := []*Node{}
|
||
|
|
for _, n := range relationship.Data {
|
||
|
|
appendIncluded(included, n)
|
||
|
|
shallowNodes = append(shallowNodes, toShallowNode(n))
|
||
|
|
}
|
||
|
|
|
||
|
|
node.Relationships[args[1]] = &RelationshipManyNode{
|
||
|
|
Data: shallowNodes,
|
||
|
|
Links: relationship.Links,
|
||
|
|
Meta: relationship.Meta,
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
node.Relationships[args[1]] = relationship
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
// to-one relationships
|
||
|
|
|
||
|
|
// Handle null relationship case
|
||
|
|
if fieldValue.IsNil() {
|
||
|
|
node.Relationships[args[1]] = &RelationshipOneNode{Data: nil}
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
|
||
|
|
relationship, err := visitModelNode(
|
||
|
|
fieldValue.Interface(),
|
||
|
|
included,
|
||
|
|
sideload,
|
||
|
|
)
|
||
|
|
if err != nil {
|
||
|
|
er = err
|
||
|
|
break
|
||
|
|
}
|
||
|
|
|
||
|
|
if sideload {
|
||
|
|
appendIncluded(included, relationship)
|
||
|
|
node.Relationships[args[1]] = &RelationshipOneNode{
|
||
|
|
Data: toShallowNode(relationship),
|
||
|
|
Links: relLinks,
|
||
|
|
Meta: relMeta,
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
node.Relationships[args[1]] = &RelationshipOneNode{
|
||
|
|
Data: relationship,
|
||
|
|
Links: relLinks,
|
||
|
|
Meta: relMeta,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
} else {
|
||
|
|
er = ErrBadJSONAPIStructTag
|
||
|
|
break
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if er != nil {
|
||
|
|
return nil, er
|
||
|
|
}
|
||
|
|
|
||
|
|
if linkableModel, isLinkable := model.(Linkable); isLinkable {
|
||
|
|
jl := linkableModel.JSONAPILinks()
|
||
|
|
if er := jl.validate(); er != nil {
|
||
|
|
return nil, er
|
||
|
|
}
|
||
|
|
node.Links = linkableModel.JSONAPILinks()
|
||
|
|
}
|
||
|
|
|
||
|
|
if metableModel, ok := model.(Metable); ok {
|
||
|
|
node.Meta = metableModel.JSONAPIMeta()
|
||
|
|
}
|
||
|
|
|
||
|
|
return node, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func toShallowNode(node *Node) *Node {
|
||
|
|
return &Node{
|
||
|
|
ID: node.ID,
|
||
|
|
Type: node.Type,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func visitModelNodeRelationships(models reflect.Value, included *map[string]*Node,
|
||
|
|
sideload bool) (*RelationshipManyNode, error) {
|
||
|
|
nodes := []*Node{}
|
||
|
|
|
||
|
|
for i := 0; i < models.Len(); i++ {
|
||
|
|
n := models.Index(i).Interface()
|
||
|
|
|
||
|
|
node, err := visitModelNode(n, included, sideload)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
nodes = append(nodes, node)
|
||
|
|
}
|
||
|
|
|
||
|
|
return &RelationshipManyNode{Data: nodes}, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func appendIncluded(m *map[string]*Node, nodes ...*Node) {
|
||
|
|
included := *m
|
||
|
|
|
||
|
|
for _, n := range nodes {
|
||
|
|
k := fmt.Sprintf("%s,%s", n.Type, n.ID)
|
||
|
|
|
||
|
|
if _, hasNode := included[k]; hasNode {
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
|
||
|
|
included[k] = n
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func nodeMapValues(m *map[string]*Node) []*Node {
|
||
|
|
mp := *m
|
||
|
|
nodes := make([]*Node, len(mp))
|
||
|
|
|
||
|
|
i := 0
|
||
|
|
for _, n := range mp {
|
||
|
|
nodes[i] = n
|
||
|
|
i++
|
||
|
|
}
|
||
|
|
|
||
|
|
return nodes
|
||
|
|
}
|
||
|
|
|
||
|
|
func convertToSliceInterface(i *interface{}) ([]interface{}, error) {
|
||
|
|
vals := reflect.ValueOf(*i)
|
||
|
|
if vals.Kind() != reflect.Slice {
|
||
|
|
return nil, ErrExpectedSlice
|
||
|
|
}
|
||
|
|
var response []interface{}
|
||
|
|
for x := 0; x < vals.Len(); x++ {
|
||
|
|
response = append(response, vals.Index(x).Interface())
|
||
|
|
}
|
||
|
|
return response, nil
|
||
|
|
}
|