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
|
/*
* Copyright (C) 2020-2021 Yomichan Authors
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
class TemplateRendererProxy {
constructor() {
this._frame = null;
this._frameNeedsLoad = true;
this._frameLoading = false;
this._frameLoadPromise = null;
this._frameUrl = chrome.runtime.getURL('/template-renderer.html');
this._invocations = new Set();
}
async render(template, data, type) {
await this._prepareFrame();
return await this._invoke('render', {template, data, type});
}
async renderMulti(items) {
await this._prepareFrame();
return await this._invoke('renderMulti', {items});
}
async getModifiedData(data, type) {
await this._prepareFrame();
return await this._invoke('getModifiedData', {data, type});
}
// Private
async _prepareFrame() {
if (this._frame === null) {
this._frame = document.createElement('iframe');
this._frame.addEventListener('load', this._onFrameLoad.bind(this), false);
const style = this._frame.style;
style.opacity = '0';
style.width = '0';
style.height = '0';
style.position = 'absolute';
style.border = '0';
style.margin = '0';
style.padding = '0';
style.pointerEvents = 'none';
}
if (this._frameNeedsLoad) {
this._frameNeedsLoad = false;
this._frameLoading = true;
this._frameLoadPromise = this._loadFrame(this._frame, this._frameUrl)
.finally(() => { this._frameLoading = false; });
}
await this._frameLoadPromise;
}
_loadFrame(frame, url, timeout=5000) {
return new Promise((resolve, reject) => {
let state = 0x0; // 0x1 = frame added; 0x2 = frame loaded; 0x4 = frame ready
const cleanup = () => {
frame.removeEventListener('load', onLoad, false);
window.removeEventListener('message', onWindowMessage, false);
if (timer !== null) {
clearTimeout(timer);
timer = null;
}
};
const updateState = (flags) => {
state |= flags;
if (state !== 0x7) { return; }
cleanup();
resolve();
};
const onLoad = () => {
if ((state & 0x3) !== 0x1) { return; }
updateState(0x2);
};
const onWindowMessage = (e) => {
if ((state & 0x5) !== 0x1) { return; }
const frameWindow = frame.contentWindow;
if (frameWindow === null || frameWindow !== e.source) { return; }
const {data} = e;
if (!(typeof data === 'object' && data !== null && data.action === 'ready')) { return; }
updateState(0x4);
};
let timer = setTimeout(() => {
timer = null;
cleanup();
reject(new Error('Timeout'));
}, timeout);
frame.removeAttribute('src');
frame.removeAttribute('srcdoc');
frame.addEventListener('load', onLoad, false);
window.addEventListener('message', onWindowMessage, false);
try {
document.body.appendChild(frame);
state = 0x1;
frame.contentDocument.location.href = url;
} catch (e) {
cleanup();
reject(e);
}
});
}
_invoke(action, params, timeout=null) {
return new Promise((resolve, reject) => {
const frameWindow = (this._frame !== null ? this._frame.contentWindow : null);
if (frameWindow === null) {
reject(new Error('Frame not set up'));
return;
}
const id = generateId(16);
const invocation = {
cancel: () => {
cleanup();
reject(new Error('Terminated'));
}
};
const cleanup = () => {
this._invocations.delete(invocation);
window.removeEventListener('message', onMessage, false);
if (timer !== null) {
clearTimeout(timer);
timer = null;
}
};
const onMessage = (e) => {
if (
e.source !== frameWindow ||
e.data.id !== id ||
e.data.action !== `${action}.response`
) {
return;
}
const response = e.data.params;
cleanup();
const {error} = response;
if (error) {
reject(deserializeError(error));
} else {
resolve(response.result);
}
};
let timer = (typeof timeout === 'number' ? setTimeout(() => {
cleanup();
reject(new Error('Timeout'));
}, timeout) : null);
this._invocations.add(invocation);
window.addEventListener('message', onMessage, false);
frameWindow.postMessage({action, params, id}, '*');
});
}
_onFrameLoad() {
if (this._frameLoading) { return; }
this._frameNeedsLoad = true;
for (const invocation of this._invocations) {
invocation.cancel();
}
this._invocations.clear();
}
}
|