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Package jsonapi

v0.1.74
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The latest major version is .

Published: Sep 23, 2020 | Licenses: MIT , MIT | Module: github.com/pace/bricks

Overview

Package jsonapi provides a serializer and deserializer for jsonapi.org spec payloads.

You can keep your model structs as is and use struct field tags to indicate to jsonapi how you want your response built or your request deserialzied. What about my relationships? jsonapi supports relationships out of the box and will even side load them in your response into an "included" array--that contains associated objects.

jsonapi uses StructField tags to annotate the structs fields that you already have and use in your app and then reads and writes jsonapi.org output based on the instructions you give the library in your jsonapi tags.

Example structs using a Blog > Post > Comment structure,

type Blog struct {
	ID            int       `jsonapi:"primary,blogs"`
	Title         string    `jsonapi:"attr,title"`
	Posts         []*Post   `jsonapi:"relation,posts"`
	CurrentPost   *Post     `jsonapi:"relation,current_post"`
	CurrentPostID int       `jsonapi:"attr,current_post_id"`
	CreatedAt     time.Time `jsonapi:"attr,created_at"`
	ViewCount     int       `jsonapi:"attr,view_count"`
}

type Post struct {
	ID       int        `jsonapi:"primary,posts"`
	BlogID   int        `jsonapi:"attr,blog_id"`
	Title    string     `jsonapi:"attr,title"`
	Body     string     `jsonapi:"attr,body"`
	Comments []*Comment `jsonapi:"relation,comments"`
}

type Comment struct {
	ID     int    `jsonapi:"primary,comments"`
	PostID int    `jsonapi:"attr,post_id"`
	Body   string `jsonapi:"attr,body"`
}

jsonapi Tag Reference

Value, primary: "primary,<type field output>"

This indicates that this is the primary key field for this struct type. Tag value arguments are comma separated. The first argument must be, "primary", and the second must be the name that should appear in the "type" field for all data objects that represent this type of model.

Value, attr: "attr,<key name in attributes hash>[,<extra arguments>]"

These fields' values should end up in the "attribute" hash for a record. The first argument must be, "attr', and the second should be the name for the key to display in the "attributes" hash for that record.

The following extra arguments are also supported:

"omitempty": excludes the fields value from the "attribute" hash. "iso8601": uses the ISO8601 timestamp format when serialising or deserialising the time.Time value.

Value, relation: "relation,<key name in relationships hash>"

Relations are struct fields that represent a one-to-one or one-to-many to other structs. jsonapi will traverse the graph of relationships and marshal or unmarshal records. The first argument must be, "relation", and the second should be the name of the relationship, used as the key in the "relationships" hash for the record.

Use the methods below to Marshal and Unmarshal jsonapi.org json payloads.

Visit the readme at https://github.com/google/jsonapi

Index

Constants

const (

	// MediaType is the identifier for the JSON API media type
	//
	// see http://jsonapi.org/format/#document-structure
	MediaType = "application/vnd.api+json"

	// KeyFirstPage is the key to the links object whose value contains a link to
	// the first page of data
	KeyFirstPage = "first"
	// KeyLastPage is the key to the links object whose value contains a link to
	// the last page of data
	KeyLastPage = "last"
	// KeyPreviousPage is the key to the links object whose value contains a link
	// to the previous page of data
	KeyPreviousPage = "prev"
	// KeyNextPage is the key to the links object whose value contains a link to
	// the next page of data
	KeyNextPage = "next"

	// QueryParamPageNumber is a JSON API query parameter used in a page based
	// pagination strategy in conjunction with QueryParamPageSize
	QueryParamPageNumber = "page[number]"
	// QueryParamPageSize is a JSON API query parameter used in a page based
	// pagination strategy in conjunction with QueryParamPageNumber
	QueryParamPageSize = "page[size]"

	// QueryParamPageOffset is a JSON API query parameter used in an offset based
	// pagination strategy in conjunction with QueryParamPageLimit
	QueryParamPageOffset = "page[offset]"
	// QueryParamPageLimit is a JSON API query parameter used in an offset based
	// pagination strategy in conjunction with QueryParamPageOffset
	QueryParamPageLimit = "page[limit]"

	// QueryParamPageCursor is a JSON API query parameter used with a cursor-based
	// strategy
	QueryParamPageCursor = "page[cursor]"
)

Variables

var (
	// ErrInvalidTime is returned when a struct has a time.Time type field, but
	// the JSON value was not a unix timestamp integer.
	ErrInvalidTime = errors.New("Only numbers can be parsed as dates, unix timestamps")
	// ErrInvalidISO8601 is returned when a struct has a time.Time type field and includes
	// "iso8601" in the tag spec, but the JSON value was not an ISO8601 timestamp string.
	ErrInvalidISO8601 = errors.New("Only strings can be parsed as dates, ISO8601 timestamps")
	// ErrUnknownFieldNumberType is returned when the JSON value was a float
	// (numeric) but the Struct field was a non numeric type (i.e. not int, uint,
	// float, etc)
	ErrUnknownFieldNumberType = errors.New("The struct field was not of a known number type")
	// ErrInvalidType is returned when the given type is incompatible with the expected type.
	ErrInvalidType = errors.New("Invalid type provided") // I wish we used punctuation.

)
var (
	// ErrBadJSONAPIStructTag is returned when the Struct field's JSON API
	// annotation is invalid.
	ErrBadJSONAPIStructTag = errors.New("Bad jsonapi struct tag format")
	// ErrBadJSONAPIID is returned when the Struct JSON API annotated "id" field
	// was not a valid numeric type.
	ErrBadJSONAPIID = errors.New(
		"id should be either string, int(8,16,32,64) or uint(8,16,32,64)")
	// ErrExpectedSlice is returned when a variable or argument was expected to
	// be a slice of *Structs; MarshalMany will return this error when its
	// interface{} argument is invalid.
	ErrExpectedSlice = errors.New("models should be a slice of struct pointers")
	// ErrUnexpectedType is returned when marshalling an interface; the interface
	// had to be a pointer or a slice; otherwise this error is returned.
	ErrUnexpectedType = errors.New("models should be a struct pointer or slice of struct pointers")
)

func MarshalErrors

func MarshalErrors(w io.Writer, errorObjects []*ErrorObject) error

MarshalErrors writes a JSON API response using the given `[]error`.

For more information on JSON API error payloads, see the spec here: http://jsonapi.org/format/#document-top-level and here: http://jsonapi.org/format/#error-objects.

func MarshalOnePayloadEmbedded

func MarshalOnePayloadEmbedded(w io.Writer, model interface{}) error

MarshalOnePayloadEmbedded - This method not meant to for use in implementation code, although feel free. The purpose of this method is for use in tests. In most cases, your request payloads for create will be embedded rather than sideloaded for related records. This method will serialize a single struct pointer into an embedded json response. In other words, there will be no, "included", array in the json all relationships will be serailized inline in the data.

However, in tests, you may want to construct payloads to post to create methods that are embedded to most closely resemble the payloads that will be produced by the client. This is what this method is intended for.

model interface{} should be a pointer to a struct.

func MarshalPayload

func MarshalPayload(w io.Writer, models interface{}) error

MarshalPayload writes a jsonapi response for one or many records. The related records are sideloaded into the "included" array. If this method is given a struct pointer as an argument it will serialize in the form "data": {...}. If this method is given a slice of pointers, this method will serialize in the form "data": [...]

One Example: you could pass it, w, your http.ResponseWriter, and, models, a ptr to a Blog to be written to the response body:

 func ShowBlog(w http.ResponseWriter, r *http.Request) {
	 blog := &Blog{}

	 w.Header().Set("Content-Type", jsonapi.MediaType)
	 w.WriteHeader(http.StatusOK)

	 if err := jsonapi.MarshalPayload(w, blog); err != nil {
		 http.Error(w, err.Error(), http.StatusInternalServerError)
	 }
 }

Many Example: you could pass it, w, your http.ResponseWriter, and, models, a slice of Blog struct instance pointers to be written to the response body:

	 func ListBlogs(w http.ResponseWriter, r *http.Request) {
    blogs := []*Blog{}

		 w.Header().Set("Content-Type", jsonapi.MediaType)
		 w.WriteHeader(http.StatusOK)

		 if err := jsonapi.MarshalPayload(w, blogs); err != nil {
			 http.Error(w, err.Error(), http.StatusInternalServerError)
		 }
	 }

func MarshalPayloadWithoutIncluded

func MarshalPayloadWithoutIncluded(w io.Writer, model interface{}) error

MarshalPayloadWithoutIncluded writes a jsonapi response with one or many records, without the related records sideloaded into "included" array. If you want to serialize the relations into the "included" array see MarshalPayload.

models interface{} should be either a struct pointer or a slice of struct pointers.

func UnmarshalManyPayload

func UnmarshalManyPayload(in io.Reader, t reflect.Type) ([]interface{}, error)

UnmarshalManyPayload converts an io into a set of struct instances using jsonapi tags on the type's struct fields.

func UnmarshalPayload

func UnmarshalPayload(in io.Reader, model interface{}) error

UnmarshalPayload converts an io into a struct instance using jsonapi tags on struct fields. This method supports single request payloads only, at the moment. Bulk creates and updates are not supported yet.

Will Unmarshal embedded and sideloaded payloads. The latter is only possible if the object graph is complete. That is, in the "relationships" data there are type and id, keys that correspond to records in the "included" array.

For example you could pass it, in, req.Body and, model, a BlogPost struct instance to populate in an http handler,

func CreateBlog(w http.ResponseWriter, r *http.Request) {
	blog := new(Blog)

	if err := jsonapi.UnmarshalPayload(r.Body, blog); err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	// ...do stuff with your blog...

	w.Header().Set("Content-Type", jsonapi.MediaType)
	w.WriteHeader(201)

	if err := jsonapi.MarshalPayload(w, blog); err != nil {
		http.Error(w, err.Error(), 500)
	}
}

Visit https://github.com/google/jsonapi#create for more info.

model interface{} should be a pointer to a struct.

type ErrUnsupportedPtrType

type ErrUnsupportedPtrType struct {
	// contains filtered or unexported fields
}

ErrUnsupportedPtrType is returned when the Struct field was a pointer but the JSON value was of a different type

func (ErrUnsupportedPtrType) Error

func (eupt ErrUnsupportedPtrType) Error() string

type ErrorObject

type ErrorObject struct {
	// ID is a unique identifier for this particular occurrence of a problem.
	ID string `json:"id,omitempty"`

	// Title is a short, human-readable summary of the problem that SHOULD NOT change from occurrence to occurrence of the problem, except for purposes of localization.
	Title string `json:"title,omitempty"`

	// Detail is a human-readable explanation specific to this occurrence of the problem. Like title, this field’s value can be localized.
	Detail string `json:"detail,omitempty"`

	// Status is the HTTP status code applicable to this problem, expressed as a string value.
	Status string `json:"status,omitempty"`

	// Code is an application-specific error code, expressed as a string value.
	Code string `json:"code,omitempty"`

	// Meta is an object containing non-standard meta-information about the error.
	Meta *map[string]interface{} `json:"meta,omitempty"`
}

ErrorObject is an `Error` implementation as well as an implementation of the JSON API error object.

The main idea behind this struct is that you can use it directly in your code as an error type and pass it directly to `MarshalErrors` to get a valid JSON API errors payload. For more information on Golang errors, see: https://golang.org/pkg/errors/ For more information on the JSON API spec's error objects, see: http://jsonapi.org/format/#error-objects

func (*ErrorObject) Error

func (e *ErrorObject) Error() string

Error implements the `Error` interface.

type ErrorsPayload

type ErrorsPayload struct {
	Errors []*ErrorObject `json:"errors"`
}

ErrorsPayload is a serializer struct for representing a valid JSON API errors payload.

type Event

type Event int

Event represents a lifecycle event in the marshaling or unmarshalling process.

const (
	// UnmarshalStart is the Event that is sent when deserialization of a payload
	// begins.
	UnmarshalStart Event = iota

	// UnmarshalStop is the Event that is sent when deserialization of a payload
	// ends.
	UnmarshalStop

	// MarshalStart is the Event that is sent sent when serialization of a payload
	// begins.
	MarshalStart

	// MarshalStop is the Event that is sent sent when serialization of a payload
	// ends.
	MarshalStop
)

type Events

type Events func(*Runtime, Event, string, time.Duration)

Events is the func type that provides the callback for handling event timings.

var Instrumentation Events

Instrumentation is a a global Events variable. This is the handler for all timing events.

type Link struct {
	Href string `json:"href"`
	Meta Meta   `json:"meta,omitempty"`
}

Link is used to represent a member of the `links` object.

type Linkable

type Linkable interface {
	JSONAPILinks() *Links
}

Linkable is used to include document links in response data e.g. {"self": "http://example.com/posts/1"}

type Links map[string]interface{}

Links is used to represent a `links` object. http://jsonapi.org/format/#document-links

type ManyPayload

type ManyPayload struct {
	Data     []*Node `json:"data"`
	Included []*Node `json:"included,omitempty"`
	Links    *Links  `json:"links,omitempty"`
	Meta     *Meta   `json:"meta,omitempty"`
}

ManyPayload is used to represent a generic JSON API payload where many resources (Nodes) were included in an [] in the "data" key

type Meta

type Meta map[string]interface{}

Meta is used to represent a `meta` object. http://jsonapi.org/format/#document-meta

type Metable

type Metable interface {
	JSONAPIMeta() *Meta
}

Metable is used to include document meta in response data e.g. {"foo": "bar"}

type Node

type Node struct {
	Type          string                     `json:"type"`
	ID            string                     `json:"id,omitempty"`
	ClientID      string                     `json:"client-id,omitempty"`
	Attributes    map[string]json.RawMessage `json:"attributes,omitempty"`
	Relationships map[string]interface{}     `json:"relationships,omitempty"`
	Links         *Links                     `json:"links,omitempty"`
	Meta          *Meta                      `json:"meta,omitempty"`
}

Node is used to represent a generic JSON API Resource

type OnePayload

type OnePayload struct {
	Data     *Node   `json:"data"`
	Included []*Node `json:"included,omitempty"`
	Links    *Links  `json:"links,omitempty"`
	Meta     *Meta   `json:"meta,omitempty"`
}

OnePayload is used to represent a generic JSON API payload where a single resource (Node) was included as an {} in the "data" key

type Payloader

type Payloader interface {
	// contains filtered or unexported methods
}

Payloader is used to encapsulate the One and Many payload types

func Marshal

func Marshal(models interface{}) (Payloader, error)

Marshal does the same as MarshalPayload except it just returns the payload and doesn't write out results. Useful if you use your own JSON rendering library.

type RelationshipLinkable

type RelationshipLinkable interface {
	// JSONAPIRelationshipLinks will be invoked for each relationship with the corresponding relation name (e.g. `comments`)
	JSONAPIRelationshipLinks(relation string) *Links
}

RelationshipLinkable is used to include relationship links in response data e.g. {"related": "http://example.com/posts/1/comments"}

type RelationshipManyNode

type RelationshipManyNode struct {
	Data  []*Node `json:"data"`
	Links *Links  `json:"links,omitempty"`
	Meta  *Meta   `json:"meta,omitempty"`
}

RelationshipManyNode is used to represent a generic has many JSON API relation

type RelationshipMetable

type RelationshipMetable interface {
	// JSONRelationshipMeta will be invoked for each relationship with the corresponding relation name (e.g. `comments`)
	JSONAPIRelationshipMeta(relation string) *Meta
}

RelationshipMetable is used to include relationship meta in response data

type RelationshipOneNode

type RelationshipOneNode struct {
	Data  *Node  `json:"data"`
	Links *Links `json:"links,omitempty"`
	Meta  *Meta  `json:"meta,omitempty"`
}

RelationshipOneNode is used to represent a generic has one JSON API relation

type Runtime

type Runtime struct {
	// contains filtered or unexported fields
}

Runtime has the same methods as jsonapi package for serialization and deserialization but also has a ctx, a map[string]interface{} for storing state, designed for instrumenting serialization timings.

func NewRuntime

func NewRuntime() *Runtime

NewRuntime creates a Runtime for use in an application.

func (*Runtime) Instrument

func (r *Runtime) Instrument(key string) *Runtime

Instrument is deprecated.

func (*Runtime) MarshalPayload

func (r *Runtime) MarshalPayload(w io.Writer, model interface{}) error

MarshalPayload has docs in response.go for MarshalPayload.

func (*Runtime) UnmarshalManyPayload

func (r *Runtime) UnmarshalManyPayload(reader io.Reader, kind reflect.Type) (elems []interface{}, err error)

UnmarshalManyPayload has docs in request.go for UnmarshalManyPayload.

func (*Runtime) UnmarshalPayload

func (r *Runtime) UnmarshalPayload(reader io.Reader, model interface{}) error

UnmarshalPayload has docs in request.go for UnmarshalPayload.

func (*Runtime) Value

func (r *Runtime) Value(key string) interface{}

Value returns a state variable in the runtime context.

func (*Runtime) WithValue

func (r *Runtime) WithValue(key string, value interface{}) *Runtime

WithValue adds custom state variables to the runtime context.

Package Files

Documentation was rendered with GOOS=linux and GOARCH=amd64.

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