Repository navigation
Expand file tree
/
Copy pathcontext.go
More file actions
433 lines (371 loc) · 11.6 KB
/
Copy pathcontext.go
File metadata and controls
433 lines (371 loc) · 11.6 KB
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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
// Copyright 2014 Manu Martinez-Almeida. All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.
package gin
import (
"errors"
"fmt"
"math"
"net/http"
"strings"
"github.com/gin-gonic/gin/binding"
"github.com/gin-gonic/gin/render"
"golang.org/x/net/context"
)
const (
MIMEJSON = binding.MIMEJSON
MIMEHTML = binding.MIMEHTML
MIMEXML = binding.MIMEXML
MIMEXML2 = binding.MIMEXML2
MIMEPlain = binding.MIMEPlain
MIMEPOSTForm = binding.MIMEPOSTForm
MIMEMultipartPOSTForm = binding.MIMEMultipartPOSTForm
)
const AbortIndex = math.MaxInt8 / 2
// Param is a single URL parameter, consisting of a key and a value.
type Param struct {
Key string
Value string
}
// Params is a Param-slice, as returned by the router.
// The slice is ordered, the first URL parameter is also the first slice value.
// It is therefore safe to read values by the index.
type Params []Param
// ByName returns the value of the first Param which key matches the given name.
// If no matching Param is found, an empty string is returned.
func (ps Params) ByName(name string) string {
for _, entry := range ps {
if entry.Key == name {
return entry.Value
}
}
return ""
}
// Context is the most important part of gin. It allows us to pass variables between middleware,
// manage the flow, validate the JSON of a request and render a JSON response for example.
type Context struct {
context.Context
writermem responseWriter
Request *http.Request
Writer ResponseWriter
Params Params
handlers []HandlerFunc
index int8
Engine *Engine
Keys map[string]interface{}
Errors errorMsgs
Accepted []string
}
/************************************/
/********** CONTEXT CREATION ********/
/************************************/
func (c *Context) reset() {
c.Writer = &c.writermem
c.Params = c.Params[0:0]
c.handlers = nil
c.index = -1
c.Keys = nil
c.Errors = c.Errors[0:0]
c.Accepted = nil
}
func (c *Context) Copy() *Context {
var cp Context = *c
cp.writermem.ResponseWriter = nil
cp.Writer = &cp.writermem
cp.index = AbortIndex
cp.handlers = nil
return &cp
}
/************************************/
/*************** FLOW ***************/
/************************************/
// Next should be used only in the middlewares.
// It executes the pending handlers in the chain inside the calling handler.
// See example in github.
func (c *Context) Next() {
c.index++
s := int8(len(c.handlers))
for ; c.index < s; c.index++ {
c.handlers[c.index](c)
}
}
// Forces the system to not continue calling the pending handlers in the chain.
func (c *Context) Abort() {
c.index = AbortIndex
}
// Same than AbortWithStatus() but also writes the specified response status code.
// For example, the first handler checks if the request is authorized. If it's not, context.AbortWithStatus(401) should be called.
func (c *Context) AbortWithStatus(code int) {
c.Writer.WriteHeader(code)
c.Abort()
}
func (c *Context) IsAborted() bool {
return c.index == AbortIndex
}
/************************************/
/********* ERROR MANAGEMENT *********/
/************************************/
// Fail is the same as Abort plus an error message.
// Calling `context.Fail(500, err)` is equivalent to:
// ```
// context.Error("Operation aborted", err)
// context.AbortWithStatus(500)
// ```
func (c *Context) Fail(code int, err error) {
c.Error(err, "Operation aborted")
c.AbortWithStatus(code)
}
func (c *Context) ErrorTyped(err error, typ int, meta interface{}) {
c.Errors = append(c.Errors, errorMsg{
Err: err.Error(),
Type: typ,
Meta: meta,
})
}
// Attaches an error to the current context. The error is pushed to a list of errors.
// It's a good idea to call Error for each error that occurred during the resolution of a request.
// A middleware can be used to collect all the errors and push them to a database together, print a log, or append it in the HTTP response.
func (c *Context) Error(err error, meta interface{}) {
c.ErrorTyped(err, ErrorTypeExternal, meta)
}
func (c *Context) LastError() error {
nuErrors := len(c.Errors)
if nuErrors > 0 {
return errors.New(c.Errors[nuErrors-1].Err)
}
return nil
}
/************************************/
/************ INPUT DATA ************/
/************************************/
/** Shortcut for c.Request.FormValue(key) */
func (c *Context) FormValue(key string) (va string) {
va, _ = c.formValue(key)
return
}
/** Shortcut for c.Request.PostFormValue(key) */
func (c *Context) PostFormValue(key string) (va string) {
va, _ = c.postFormValue(key)
return
}
/** Shortcut for c.Params.ByName(key) */
func (c *Context) ParamValue(key string) (va string) {
va, _ = c.paramValue(key)
return
}
func (c *Context) DefaultPostFormValue(key, defaultValue string) string {
if va, ok := c.postFormValue(key); ok {
return va
} else {
return defaultValue
}
}
func (c *Context) DefaultFormValue(key, defaultValue string) string {
if va, ok := c.formValue(key); ok {
return va
} else {
return defaultValue
}
}
func (c *Context) DefaultParamValue(key, defaultValue string) string {
if va, ok := c.paramValue(key); ok {
return va
} else {
return defaultValue
}
}
func (c *Context) paramValue(key string) (string, bool) {
va := c.Params.ByName(key)
return va, len(va) > 0
}
func (c *Context) formValue(key string) (string, bool) {
req := c.Request
req.ParseForm()
if values, ok := req.Form[key]; ok && len(values) > 0 {
return values[0], true
}
return "", false
}
func (c *Context) postFormValue(key string) (string, bool) {
req := c.Request
req.ParseForm()
if values, ok := req.PostForm[key]; ok && len(values) > 0 {
return values[0], true
}
return "", false
}
/************************************/
/******** METADATA MANAGEMENT********/
/************************************/
// Sets a new pair key/value just for the specified context.
// It also lazy initializes the hashmap.
func (c *Context) Set(key string, item interface{}) {
if c.Keys == nil {
c.Keys = make(map[string]interface{})
}
c.Keys[key] = item
}
// Get returns the value for the given key or an error if the key does not exist.
func (c *Context) Get(key string) (value interface{}, ok bool) {
if c.Keys != nil {
value, ok = c.Keys[key]
}
return
}
// MustGet returns the value for the given key or panics if the value doesn't exist.
func (c *Context) MustGet(key string) interface{} {
if value, exists := c.Get(key); exists {
return value
} else {
panic("Key \"" + key + "\" does not exist")
}
}
func (c *Context) Value(key interface{}) interface{} {
if key == 0 {
return c.Request
}
if keyAsString, ok := key.(string); ok {
val, _ := c.Get(keyAsString)
return val
}
return c.Context.Value(key)
}
/************************************/
/********* PARSING REQUEST **********/
/************************************/
func (c *Context) ClientIP() string {
clientIP := c.Request.Header.Get("X-Real-IP")
if len(clientIP) > 0 {
return clientIP
}
clientIP = c.Request.Header.Get("X-Forwarded-For")
clientIP = strings.Split(clientIP, ",")[0]
if len(clientIP) > 0 {
return strings.TrimSpace(clientIP)
}
return c.Request.RemoteAddr
}
func (c *Context) ContentType() string {
return filterFlags(c.Request.Header.Get("Content-Type"))
}
// This function checks the Content-Type to select a binding engine automatically,
// Depending the "Content-Type" header different bindings are used:
// "application/json" --> JSON binding
// "application/xml" --> XML binding
// else --> returns an error
// if Parses the request's body as JSON if Content-Type == "application/json" using JSON or XML as a JSON input. It decodes the json payload into the struct specified as a pointer.Like ParseBody() but this method also writes a 400 error if the json is not valid.
func (c *Context) Bind(obj interface{}) bool {
b := binding.Default(c.Request.Method, c.ContentType())
return c.BindWith(obj, b)
}
func (c *Context) BindWith(obj interface{}, b binding.Binding) bool {
if err := b.Bind(c.Request, obj); err != nil {
c.Fail(400, err)
return false
}
return true
}
/************************************/
/******** RESPONSE RENDERING ********/
/************************************/
func (c *Context) Render(code int, render render.Render, obj ...interface{}) {
if err := render.Render(c.Writer, code, obj...); err != nil {
c.ErrorTyped(err, ErrorTypeInternal, obj)
c.AbortWithStatus(500)
}
}
// Serializes the given struct as JSON into the response body in a fast and efficient way.
// It also sets the Content-Type as "application/json".
func (c *Context) JSON(code int, obj interface{}) {
c.Render(code, render.JSON, obj)
}
// Serializes the given struct as XML into the response body in a fast and efficient way.
// It also sets the Content-Type as "application/xml".
func (c *Context) XML(code int, obj interface{}) {
c.Render(code, render.XML, obj)
}
// Renders the HTTP template specified by its file name.
// It also updates the HTTP code and sets the Content-Type as "text/html".
// See http://golang.org/doc/articles/wiki/
func (c *Context) HTML(code int, name string, obj interface{}) {
c.Render(code, c.Engine.HTMLRender, name, obj)
}
// Writes the given string into the response body and sets the Content-Type to "text/plain".
func (c *Context) String(code int, format string, values ...interface{}) {
c.Render(code, render.Plain, format, values)
}
// Writes the given string into the response body and sets the Content-Type to "text/html" without template.
func (c *Context) HTMLString(code int, format string, values ...interface{}) {
c.Render(code, render.HTMLPlain, format, values)
}
// Returns a HTTP redirect to the specific location.
func (c *Context) Redirect(code int, location string) {
if code >= 300 && code <= 308 {
c.Render(code, render.Redirect, c.Request, location)
} else {
panic(fmt.Sprintf("Cannot redirect with status code %d", code))
}
}
// Writes some data into the body stream and updates the HTTP code.
func (c *Context) Data(code int, contentType string, data []byte) {
if len(contentType) > 0 {
c.Writer.Header().Set("Content-Type", contentType)
}
c.Writer.WriteHeader(code)
c.Writer.Write(data)
}
// Writes the specified file into the body stream
func (c *Context) File(filepath string) {
http.ServeFile(c.Writer, c.Request, filepath)
}
/************************************/
/******** CONTENT NEGOTIATION *******/
/************************************/
type Negotiate struct {
Offered []string
HTMLPath string
HTMLData interface{}
JSONData interface{}
XMLData interface{}
Data interface{}
}
func (c *Context) Negotiate(code int, config Negotiate) {
switch c.NegotiateFormat(config.Offered...) {
case binding.MIMEJSON:
data := chooseData(config.JSONData, config.Data)
c.JSON(code, data)
case binding.MIMEHTML:
if len(config.HTMLPath) == 0 {
panic("negotiate config is wrong. html path is needed")
}
data := chooseData(config.HTMLData, config.Data)
c.HTML(code, config.HTMLPath, data)
case binding.MIMEXML:
data := chooseData(config.XMLData, config.Data)
c.XML(code, data)
default:
c.Fail(http.StatusNotAcceptable, errors.New("the accepted formats are not offered by the server"))
}
}
func (c *Context) NegotiateFormat(offered ...string) string {
if len(offered) == 0 {
panic("you must provide at least one offer")
}
if c.Accepted == nil {
c.Accepted = parseAccept(c.Request.Header.Get("Accept"))
}
if len(c.Accepted) == 0 {
return offered[0]
}
for _, accepted := range c.Accepted {
for _, offert := range offered {
if accepted == offert {
return offert
}
}
}
return ""
}
func (c *Context) SetAccepted(formats ...string) {
c.Accepted = formats
}