This repository has been archived by the owner on Apr 26, 2024. It is now read-only.
forked from shurcooL/graphql
/
graphql.go
133 lines (120 loc) · 3.7 KB
/
graphql.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
package graphql
import (
"bytes"
"context"
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"github.com/shurcooL/graphql/internal/jsonutil"
"golang.org/x/net/context/ctxhttp"
)
// Client is a GraphQL client.
type Client struct {
url string // GraphQL server URL.
httpClient *http.Client
}
// NewClient creates a GraphQL client targeting the specified GraphQL server URL.
// If httpClient is nil, then http.DefaultClient is used.
func NewClient(url string, httpClient *http.Client) *Client {
if httpClient == nil {
httpClient = http.DefaultClient
}
return &Client{
url: url,
httpClient: httpClient,
}
}
// Query executes a single GraphQL query request,
// with a query derived from q, populating the response into it.
// q should be a pointer to struct that corresponds to the GraphQL schema.
func (c *Client) Query(ctx context.Context, q interface{}, variables map[string]interface{}) error {
_, err := c.do(ctx, queryOperation, q, variables)
return err
}
func (c *Client) QueryAndReturnHeader(ctx context.Context, q interface{}, variables map[string]interface{}) (http.Header, error) {
return c.do(ctx, queryOperation, q, variables)
}
// Mutate executes a single GraphQL mutation request,
// with a mutation derived from m, populating the response into it.
// m should be a pointer to struct that corresponds to the GraphQL schema.
func (c *Client) Mutate(ctx context.Context, m interface{}, variables map[string]interface{}) error {
_, err := c.do(ctx, mutationOperation, m, variables)
return err
}
func (c *Client) MutateAndReturnHeader(ctx context.Context, m interface{}, variables map[string]interface{}) (http.Header, error) {
return c.do(ctx, mutationOperation, m, variables)
}
// do executes a single GraphQL operation.
func (c *Client) do(ctx context.Context, op operationType, v interface{}, variables map[string]interface{}) (http.Header, error) {
var query string
switch op {
case queryOperation:
query = constructQuery(v, variables)
case mutationOperation:
query = constructMutation(v, variables)
}
in := struct {
Query string `json:"query"`
Variables map[string]interface{} `json:"variables,omitempty"`
}{
Query: query,
Variables: variables,
}
var buf bytes.Buffer
err := json.NewEncoder(&buf).Encode(in)
if err != nil {
return nil, err
}
resp, err := ctxhttp.Post(ctx, c.httpClient, c.url, "application/json", &buf)
if err != nil {
return nil, err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
body, _ := ioutil.ReadAll(resp.Body)
return resp.Header, fmt.Errorf("non-200 OK status code: %v body: %q", resp.Status, body)
}
var out struct {
Data *json.RawMessage
Errors errors
//Extensions interface{} // Unused.
}
err = json.NewDecoder(resp.Body).Decode(&out)
if err != nil {
// TODO: Consider including response body in returned error, if deemed helpful.
return resp.Header, err
}
if out.Data != nil {
err := jsonutil.UnmarshalGraphQL(*out.Data, v)
if err != nil {
// TODO: Consider including response body in returned error, if deemed helpful.
return resp.Header, err
}
}
if len(out.Errors) > 0 {
return resp.Header, out.Errors
}
return resp.Header, nil
}
// errors represents the "errors" array in a response from a GraphQL server.
// If returned via error interface, the slice is expected to contain at least 1 element.
//
// Specification: https://facebook.github.io/graphql/#sec-Errors.
type errors []struct {
Message string
Locations []struct {
Line int
Column int
}
}
// Error implements error interface.
func (e errors) Error() string {
return e[0].Message
}
type operationType uint8
const (
queryOperation operationType = iota
mutationOperation
//subscriptionOperation // Unused.
)