/
http.go
1054 lines (905 loc) · 24.6 KB
/
http.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
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
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
package app
import (
"bytes"
"crypto/sha1"
"encoding/json"
"fmt"
"io"
"net/http"
"os"
"path/filepath"
"reflect"
"sort"
"strconv"
"strings"
"sync"
"text/template"
"time"
"github.com/maxence-charriere/go-app/v9/pkg/errors"
)
const (
defaultThemeColor = "#2d2c2c"
)
// Handler is an HTTP handler that serves an HTML page that loads a Go wasm app
// and its resources.
type Handler struct {
// The name of the web application as it is usually displayed to the user.
Name string
// The name of the web application displayed to the user when there is not
// enough space to display Name.
ShortName string
// The icon that is used for the PWA, favicon, loading and default not
// found component.
Icon Icon
// A placeholder background color for the application page to display before
// its stylesheets are loaded.
//
// Default: #2d2c2c.
BackgroundColor string
// The theme color for the application. This affects how the OS displays the
// app (e.g., PWA title bar or Android's task switcher).
//
// DEFAULT: #2d2c2c.
ThemeColor string
// The text displayed while loading a page. Load progress can be inserted by
// including "{progress}" in the loading label.
//
// DEFAULT: "{progress}%".
LoadingLabel string
// The page language.
//
// DEFAULT: en.
Lang string
// The custom libraries to load with the page.
Libraries []Library
// The page title.
Title string
// The page description.
Description string
// The page authors.
Author string
// The page keywords.
Keywords []string
// The path of the default image that is used by social networks when
// linking the app.
Image string
// The paths or urls of the CSS files to use with the page.
//
// eg:
// app.Handler{
// Styles: []string{
// "/web/test.css", // Static resource
// "https://foo.com/test.css", // External resource
// },
// },
Styles []string
// The paths or urls of the font files to preload with the page.
//
// eg:
// app.Handler{
// Fonts: []string{
// "/web/test.woff2", // Static resource
// "https://foo.com/test.woff2", // External resource
// },
// },
Fonts []string
// The paths or urls of the JavaScript files to use with the page.
//
// eg:
// app.Handler{
// Scripts: []string{
// "/web/test.js", // Static resource
// "https://foo.com/test.js", // External resource
// },
// },
Scripts []string
// The path of the static resources that the browser is caching in order to
// provide offline mode.
//
// Note that Icon, Styles and Scripts are already cached by default.
//
// Paths are relative to the root directory.
CacheableResources []string
// Additional headers to be added in head element.
RawHeaders []string
// The page HTML element.
//
// Default: Html().
HTML func() HTMLHtml
// The page body element.
//
// Note that the lang attribute is always overridden by the Handler.Lang
// value.
//
// Default: Body().
Body func() HTMLBody
// The interval between each app auto-update while running in a web browser.
// Zero or negative values deactivates the auto-update mechanism.
//
// Default is 0.
AutoUpdateInterval time.Duration
// The environment variables that are passed to the progressive web app.
//
// Reserved keys:
// - GOAPP_VERSION
// - GOAPP_GOAPP_STATIC_RESOURCES_URL
Env Environment
// The URLs that are launched in the app tab or window.
//
// By default, URLs with a different domain are launched in another tab.
// Specifying internal URLs is to override that behavior. A good use case
// would be the URL for an OAuth authentication.
InternalURLs []string
// The URLs of the origins to preconnect in order to improve the user
// experience by preemptively initiating a connection to those origins.
// Preconnecting speeds up future loads from a given origin by preemptively
// performing part or all of the handshake (DNS+TCP for HTTP, and
// DNS+TCP+TLS for HTTPS origins).
Preconnect []string
// The static resources that are accessible from custom paths. Files that
// are proxied by default are /robots.txt, /sitemap.xml and /ads.txt.
ProxyResources []ProxyResource
// The resource provider that provides static resources. Static resources
// are always accessed from a path that starts with "/web/".
//
// eg:
// "/web/main.css"
//
// Default: LocalDir("")
Resources ResourceProvider
// The version number. This is used in order to update the PWA application
// in the browser. It must be set when deployed on a live system in order to
// prevent recurring updates.
//
// Default: Auto-generated in order to trigger pwa update on a local
// development system.
Version string
// The HTTP header to retrieve the WebAssembly file content length.
//
// Content length finding falls back to the Content-Length HTTP header when
// no content length is found with the defined header.
WasmContentLengthHeader string
// The template used to generate app-worker.js. The template follows the
// text/template package model.
//
// By default set to DefaultAppWorkerJS, changing the template have very
// high chances to mess up go-app usage. Any issue related to a custom app
// worker template is not supported and will be closed.
ServiceWorkerTemplate string
once sync.Once
etag string
libraries map[string][]byte
proxyResources map[string]ProxyResource
cachedProxyResources *memoryCache
cachedPWAResources *memoryCache
}
func (h *Handler) init() {
h.initVersion()
h.initStaticResources()
h.initImage()
h.initLibraries()
h.initLinks()
h.initScripts()
h.initServiceWorker()
h.initCacheableResources()
h.initIcon()
h.initPWA()
h.initPageContent()
h.initPWAResources()
h.initProxyResources()
}
func (h *Handler) initVersion() {
if h.Version == "" {
t := time.Now().UTC().String()
h.Version = fmt.Sprintf(`%x`, sha1.Sum([]byte(t)))
}
h.etag = `"` + h.Version + `"`
}
func (h *Handler) initStaticResources() {
if h.Resources == nil {
h.Resources = LocalDir("")
}
}
func (h *Handler) initImage() {
if h.Image != "" {
h.Image = h.resolveStaticPath(h.Image)
}
}
func (h *Handler) initLibraries() {
libs := make(map[string][]byte)
for _, l := range h.Libraries {
path, styles := l.Styles()
if !strings.HasPrefix(path, "/") || len(styles) == 0 {
continue
}
libs[path] = []byte(styles)
}
h.libraries = libs
}
func (h *Handler) initLinks() {
for i, path := range h.Preconnect {
h.Preconnect[i] = h.resolveStaticPath(path)
}
styles := []string{h.resolvePackagePath("/app.css")}
for path := range h.libraries {
styles = append(styles, h.resolvePackagePath(path))
}
for _, path := range h.Styles {
styles = append(styles, h.resolveStaticPath(path))
}
h.Styles = styles
for i, path := range h.Fonts {
h.Fonts[i] = h.resolveStaticPath(path)
}
}
func (h *Handler) initScripts() {
for i, path := range h.Scripts {
h.Scripts[i] = h.resolveStaticPath(path)
}
}
func (h *Handler) initServiceWorker() {
if h.ServiceWorkerTemplate == "" {
h.ServiceWorkerTemplate = DefaultAppWorkerJS
}
}
func (h *Handler) initCacheableResources() {
for i, path := range h.CacheableResources {
h.CacheableResources[i] = h.resolveStaticPath(path)
}
}
func (h *Handler) initIcon() {
if h.Icon.Default == "" {
h.Icon.Default = "https://raw.githubusercontent.com/maxence-charriere/go-app/master/docs/web/icon.png"
h.Icon.Large = "https://raw.githubusercontent.com/maxence-charriere/go-app/master/docs/web/icon.png"
}
if h.Icon.AppleTouch == "" {
h.Icon.AppleTouch = h.Icon.Default
}
if h.Icon.SVG == "" {
h.Icon.SVG = "https://raw.githubusercontent.com/maxence-charriere/go-app/master/docs/web/icon.svg"
}
h.Icon.Default = h.resolveStaticPath(h.Icon.Default)
h.Icon.Large = h.resolveStaticPath(h.Icon.Large)
h.Icon.SVG = h.resolveStaticPath(h.Icon.SVG)
h.Icon.AppleTouch = h.resolveStaticPath(h.Icon.AppleTouch)
}
func (h *Handler) initPWA() {
if h.Name == "" && h.ShortName == "" && h.Title == "" {
h.Name = "App PWA"
}
if h.ShortName == "" {
h.ShortName = h.Name
}
if h.Name == "" {
h.Name = h.ShortName
}
if h.BackgroundColor == "" {
h.BackgroundColor = defaultThemeColor
}
if h.ThemeColor == "" {
h.ThemeColor = defaultThemeColor
}
if h.Lang == "" {
h.Lang = "en"
}
if h.LoadingLabel == "" {
h.LoadingLabel = "{progress}%"
}
}
func (h *Handler) initPageContent() {
if h.HTML == nil {
h.HTML = Html
}
if h.Body == nil {
h.Body = Body
}
}
func (h *Handler) initPWAResources() {
h.cachedPWAResources = newMemoryCache(5)
h.cachedPWAResources.Set(cacheItem{
Path: "/wasm_exec.js",
ContentType: "application/javascript",
Body: []byte(wasmExecJS()),
})
h.cachedPWAResources.Set(cacheItem{
Path: "/app.js",
ContentType: "application/javascript",
Body: h.makeAppJS(),
})
h.cachedPWAResources.Set(cacheItem{
Path: "/app-worker.js",
ContentType: "application/javascript",
Body: h.makeAppWorkerJS(),
})
h.cachedPWAResources.Set(cacheItem{
Path: "/manifest.webmanifest",
ContentType: "application/manifest+json",
Body: h.makeManifestJSON(),
})
h.cachedPWAResources.Set(cacheItem{
Path: "/app.css",
ContentType: "text/css",
Body: []byte(appCSS),
})
}
func (h *Handler) makeAppJS() []byte {
if h.Env == nil {
h.Env = make(map[string]string)
}
internalURLs, _ := json.Marshal(h.InternalURLs)
h.Env["GOAPP_INTERNAL_URLS"] = string(internalURLs)
h.Env["GOAPP_VERSION"] = h.Version
h.Env["GOAPP_STATIC_RESOURCES_URL"] = h.Resources.Static()
h.Env["GOAPP_ROOT_PREFIX"] = h.Resources.Package()
for k, v := range h.Env {
if err := os.Setenv(k, v); err != nil {
Log(errors.New("setting app env variable failed").
WithTag("name", k).
WithTag("value", v).
Wrap(err))
}
}
var b bytes.Buffer
if err := template.
Must(template.New("app.js").Parse(appJS)).
Execute(&b, struct {
Env string
LoadingLabel string
Wasm string
WasmContentLengthHeader string
WorkerJS string
AutoUpdateInterval int64
}{
Env: jsonString(h.Env),
LoadingLabel: h.LoadingLabel,
Wasm: h.Resources.AppWASM(),
WasmContentLengthHeader: h.WasmContentLengthHeader,
WorkerJS: h.resolvePackagePath("/app-worker.js"),
AutoUpdateInterval: h.AutoUpdateInterval.Milliseconds(),
}); err != nil {
panic(errors.New("initializing app.js failed").Wrap(err))
}
return b.Bytes()
}
func (h *Handler) makeAppWorkerJS() []byte {
resources := make(map[string]struct{})
setResources := func(res ...string) {
for _, r := range res {
if r == "" {
continue
}
r, _, _ = parseSrc(r)
resources[r] = struct{}{}
}
}
setResources(
h.resolvePackagePath("/app.css"),
h.resolvePackagePath("/app.js"),
h.resolvePackagePath("/manifest.webmanifest"),
h.resolvePackagePath("/wasm_exec.js"),
h.resolvePackagePath("/"),
h.Resources.AppWASM(),
)
setResources(h.Icon.Default, h.Icon.Large, h.Icon.AppleTouch)
setResources(h.Styles...)
setResources(h.Fonts...)
setResources(h.Scripts...)
setResources(h.CacheableResources...)
resourcesTocache := make([]string, 0, len(resources))
for k := range resources {
resourcesTocache = append(resourcesTocache, k)
}
sort.Slice(resourcesTocache, func(a, b int) bool {
return strings.Compare(resourcesTocache[a], resourcesTocache[b]) < 0
})
var b bytes.Buffer
if err := template.
Must(template.New("app-worker.js").Parse(h.ServiceWorkerTemplate)).
Execute(&b, struct {
Version string
ResourcesToCache string
}{
Version: h.Version,
ResourcesToCache: jsonString(resourcesTocache),
}); err != nil {
panic(errors.New("initializing app-worker.js failed").Wrap(err))
}
return b.Bytes()
}
func (h *Handler) makeManifestJSON() []byte {
normalize := func(s string) string {
if !strings.HasPrefix(s, "/") {
s = "/" + s
}
if !strings.HasSuffix(s, "/") {
s += "/"
}
return s
}
var b bytes.Buffer
if err := template.
Must(template.New("manifest.webmanifest").Parse(manifestJSON)).
Execute(&b, struct {
ShortName string
Name string
Description string
DefaultIcon string
LargeIcon string
SVGIcon string
BackgroundColor string
ThemeColor string
Scope string
StartURL string
}{
ShortName: h.ShortName,
Name: h.Name,
Description: h.Description,
DefaultIcon: h.Icon.Default,
LargeIcon: h.Icon.Large,
SVGIcon: h.Icon.SVG,
BackgroundColor: h.BackgroundColor,
ThemeColor: h.ThemeColor,
Scope: normalize(h.Resources.Package()),
StartURL: normalize(h.Resources.Package()),
}); err != nil {
panic(errors.New("initializing manifest.webmanifest failed").Wrap(err))
}
return b.Bytes()
}
func (h *Handler) initProxyResources() {
h.cachedProxyResources = newMemoryCache(len(h.ProxyResources))
resources := make(map[string]ProxyResource)
for _, r := range h.ProxyResources {
switch r.Path {
case "/wasm_exec.js",
"/goapp.js",
"/app.js",
"/app-worker.js",
"/manifest.json",
"/manifest.webmanifest",
"/app.css",
"/app.wasm",
"/goapp.wasm",
"/":
continue
default:
if strings.HasPrefix(r.Path, "/") && strings.HasPrefix(r.ResourcePath, "/web/") {
resources[r.Path] = r
}
}
}
if _, ok := resources["/robots.txt"]; !ok {
resources["/robots.txt"] = ProxyResource{
Path: "/robots.txt",
ResourcePath: "/web/robots.txt",
}
}
if _, ok := resources["/sitemap.xml"]; !ok {
resources["/sitemap.xml"] = ProxyResource{
Path: "/sitemap.xml",
ResourcePath: "/web/sitemap.xml",
}
}
if _, ok := resources["/ads.txt"]; !ok {
resources["/ads.txt"] = ProxyResource{
Path: "/ads.txt",
ResourcePath: "/web/ads.txt",
}
}
h.proxyResources = resources
}
func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
h.once.Do(h.init)
w.Header().Set("Cache-Control", "no-cache")
w.Header().Set("ETag", h.etag)
etag := r.Header.Get("If-None-Match")
if etag == h.etag {
w.WriteHeader(http.StatusNotModified)
return
}
path := r.URL.Path
fileHandler, isServingStaticResources := h.Resources.(http.Handler)
if isServingStaticResources && strings.HasPrefix(path, "/web/") {
fileHandler.ServeHTTP(w, r)
return
}
switch path {
case "/goapp.js":
path = "/app.js"
case "/manifest.json":
path = "/manifest.webmanifest"
case "/app.wasm", "/goapp.wasm":
if isServingStaticResources {
r2 := *r
r2.URL.Path = h.Resources.AppWASM()
fileHandler.ServeHTTP(w, &r2)
return
}
w.WriteHeader(http.StatusNotFound)
return
}
if res, ok := h.cachedPWAResources.Get(path); ok {
h.serveCachedItem(w, res)
return
}
if proxyResource, ok := h.proxyResources[path]; ok {
h.serveProxyResource(proxyResource, w, r)
return
}
if library, ok := h.libraries[path]; ok {
h.serveLibrary(w, r, library)
return
}
h.servePage(w, r)
}
func (h *Handler) serveCachedItem(w http.ResponseWriter, i cacheItem) {
w.Header().Set("Content-Length", strconv.Itoa(i.Len()))
w.Header().Set("Content-Type", i.ContentType)
if i.ContentEncoding != "" {
w.Header().Set("Content-Encoding", i.ContentEncoding)
}
w.WriteHeader(http.StatusOK)
w.Write(i.Body)
}
func (h *Handler) serveProxyResource(resource ProxyResource, w http.ResponseWriter, r *http.Request) {
var u string
if _, ok := h.Resources.(http.Handler); ok {
var protocol string
if r.TLS != nil {
protocol = "https://"
} else {
protocol = "http://"
}
u = protocol + r.Host + resource.ResourcePath
} else {
u = h.Resources.Static() + resource.ResourcePath
}
if i, ok := h.cachedProxyResources.Get(resource.Path); ok {
h.serveCachedItem(w, i)
return
}
res, err := http.Get(u)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
Log(errors.New("getting proxy static resource failed").
WithTag("url", u).
WithTag("proxy-path", resource.Path).
WithTag("static-resource-path", resource.ResourcePath).
Wrap(err),
)
return
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
w.WriteHeader(http.StatusNotFound)
return
}
body, err := io.ReadAll(res.Body)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
Log(errors.New("reading proxy static resource failed").
WithTag("url", u).
WithTag("proxy-path", resource.Path).
WithTag("static-resource-path", resource.ResourcePath).
Wrap(err),
)
return
}
item := cacheItem{
Path: resource.Path,
ContentType: res.Header.Get("Content-Type"),
ContentEncoding: res.Header.Get("Content-Encoding"),
Body: body,
}
h.cachedProxyResources.Set(item)
h.serveCachedItem(w, item)
}
func (h *Handler) servePage(w http.ResponseWriter, r *http.Request) {
content, ok := routes.createComponent(r.URL.Path)
if !ok {
http.NotFound(w, r)
return
}
url := *r.URL
url.Host = r.Host
url.Scheme = "http"
page := requestPage{
url: &url,
resolveStaticResource: h.resolveStaticPath,
}
page.SetTitle(h.Title)
page.SetLang(h.Lang)
page.SetDescription(h.Description)
page.SetAuthor(h.Author)
page.SetKeywords(h.Keywords...)
page.SetLoadingLabel(strings.ReplaceAll(h.LoadingLabel, "{progress}", "0"))
page.SetImage(h.Image)
disp := engine{
Page: &page,
IsServerSide: true,
StaticResourceResolver: h.resolveStaticPath,
ActionHandlers: actionHandlers,
}
body := h.Body().privateBody(
Div(), // Pre-rendeging placeholder
Aside().
ID("app-wasm-loader").
Class("goapp-app-info").
Body(
Img().
ID("app-wasm-loader-icon").
Class("goapp-logo goapp-spin").
Src(h.Icon.Default),
P().
ID("app-wasm-loader-label").
Class("goapp-label").
Text(page.loadingLabel),
),
)
if err := mount(&disp, body); err != nil {
panic(errors.New("mounting pre-rendering container failed").
WithTag("server-side", disp.isServerSide()).
WithTag("body-type", reflect.TypeOf(disp.Body)).
Wrap(err))
}
disp.Body = body
disp.init()
defer disp.Close()
disp.Mount(content)
for len(disp.dispatches) != 0 {
disp.Consume()
disp.Wait()
}
icon := h.Icon.SVG
if icon == "" {
icon = h.Icon.Default
}
var b bytes.Buffer
b.WriteString("<!DOCTYPE html>\n")
PrintHTML(&b, h.HTML().
Lang(page.Lang()).
privateBody(
Head().Body(
Meta().Charset("UTF-8"),
Meta().
Name("author").
Content(page.Author()),
Meta().
Name("description").
Content(page.Description()),
Meta().
Name("keywords").
Content(page.Keywords()),
Meta().
Name("theme-color").
Content(h.ThemeColor),
Meta().
Name("viewport").
Content("width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0, viewport-fit=cover"),
Meta().
Property("og:url").
Content(page.URL().String()),
Meta().
Property("og:title").
Content(page.Title()),
Meta().
Property("og:description").
Content(page.Description()),
Meta().
Property("og:type").
Content("website"),
Meta().
Property("og:image").
Content(page.Image()),
Range(page.twitterCardMap).Map(func(k string) UI {
v := page.twitterCardMap[k]
if v == "" {
return nil
}
return Meta().
Name(k).
Content(v)
}),
Title().Text(page.Title()),
Range(h.Preconnect).Slice(func(i int) UI {
url, crossOrigin, _ := parseSrc(h.Preconnect[i])
if url == "" {
return nil
}
link := Link().
Rel("preconnect").
Href(url)
if crossOrigin != "" {
link = link.CrossOrigin(strings.Trim(crossOrigin, "true"))
}
return link
}),
Range(h.Fonts).Slice(func(i int) UI {
url, crossOrigin, _ := parseSrc(h.Fonts[i])
if url == "" {
return nil
}
link := Link().
Type("font/" + strings.TrimPrefix(filepath.Ext(url), ".")).
Rel("preload").
Href(url).
As("font")
if crossOrigin != "" {
link = link.CrossOrigin(strings.Trim(crossOrigin, "true"))
}
return link
}),
Range(page.Preloads()).Slice(func(i int) UI {
p := page.Preloads()[i]
if p.Href == "" || p.As == "" {
return nil
}
url, crossOrigin, _ := parseSrc(p.Href)
if url == "" {
return nil
}
link := Link().
Type(p.Type).
Rel("preload").
Href(url).
As(p.As).
FetchPriority(p.FetchPriority)
if crossOrigin != "" {
link = link.CrossOrigin(strings.Trim(crossOrigin, "true"))
}
return link
}),
Range(h.Styles).Slice(func(i int) UI {
url, crossOrigin, _ := parseSrc(h.Styles[i])
if url == "" {
return nil
}
link := Link().
Type("text/css").
Rel("preload").
Href(url).
As("style")
if crossOrigin != "" {
link = link.CrossOrigin(strings.Trim(crossOrigin, "true"))
}
return link
}),
Link().
Rel("icon").
Href(icon),
Link().
Rel("apple-touch-icon").
Href(h.Icon.AppleTouch),
Link().
Rel("manifest").
Href(h.resolvePackagePath("/manifest.webmanifest")),
Range(h.Styles).Slice(func(i int) UI {
url, crossOrigin, _ := parseSrc(h.Styles[i])
if url == "" {
return nil
}
link := Link().
Rel("stylesheet").
Type("text/css").
Href(url)
if crossOrigin != "" {
link = link.CrossOrigin(strings.Trim(crossOrigin, "true"))
}
return link
}),
Script().
Defer(true).
Src(h.resolvePackagePath("/wasm_exec.js")),
Script().
Defer(true).
Src(h.resolvePackagePath("/app.js")),
Range(h.Scripts).Slice(func(i int) UI {
url, crossOrigin, loading := parseSrc(h.Scripts[i])
if url == "" {
return nil
}
script := Script().Src(url)
if crossOrigin != "" {
script = script.CrossOrigin(strings.Trim(crossOrigin, "true"))
}
switch loading {
case "defer":
script = script.Defer(true)
case "async":
script.Async(true)
}
return script
}),
Range(h.RawHeaders).Slice(func(i int) UI {
return Raw(h.RawHeaders[i])
}),
),
body,
))
w.Header().Set("Content-Length", strconv.Itoa(b.Len()))
w.Header().Set("Content-Type", "text/html")
w.Write(b.Bytes())
}
func (h *Handler) serveLibrary(w http.ResponseWriter, r *http.Request, library []byte) {
w.Header().Set("Content-Length", strconv.Itoa(len(library)))
w.Header().Set("Content-Type", "text/css")
w.Write(library)
}
func (h *Handler) resolvePackagePath(path string) string {
var b strings.Builder
b.WriteByte('/')
appResources := strings.Trim(h.Resources.Package(), "/")
b.WriteString(appResources)
path = strings.Trim(path, "/")
if b.Len() != 1 && path != "" {
b.WriteByte('/')
}
b.WriteString(path)
return b.String()
}
func (h *Handler) resolveStaticPath(path string) string {
if isRemoteLocation(path) || !isStaticResourcePath(path) {
return path
}
var b strings.Builder
staticResources := strings.TrimSuffix(h.Resources.Static(), "/")
b.WriteString(staticResources)
path = strings.Trim(path, "/")
b.WriteByte('/')
b.WriteString(path)
return b.String()
}
// Icon describes a square image that is used in various places such as
// application icon, favicon or loading icon.
type Icon struct {
// The path or url to a square image/png file. It must have a side of 192px.
//
// Path is relative to the root directory.
Default string
// The path or url to larger square image/png file. It must have a side of
// 512px.
//
// Path is relative to the root directory.
Large string