/
google-chart.ts
562 lines (519 loc) · 16.5 KB
/
google-chart.ts
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
/**
* @license
* Copyright 2014-2020 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import {html, css, LitElement} from 'lit';
import {property} from 'lit/decorators.js';
import {createChartWrapper, dataTable, DataTableLike} from './loader.js';
const DEFAULT_EVENTS = ['ready', 'select'];
/**
* Constructor names for supported chart types.
*
* `ChartWrapper` expects a constructor name and assumes `google.visualization`
* as the default namespace.
*/
const CHART_TYPES: Record<string, string|undefined> = {
'area': 'AreaChart',
'bar': 'BarChart',
'md-bar': 'google.charts.Bar',
'bubble': 'BubbleChart',
'calendar': 'Calendar',
'candlestick': 'CandlestickChart',
'column': 'ColumnChart',
'combo': 'ComboChart',
'gantt': 'Gantt',
'gauge': 'Gauge',
'geo': 'GeoChart',
'histogram': 'Histogram',
'line': 'LineChart',
'md-line': 'google.charts.Line',
'org': 'OrgChart',
'pie': 'PieChart',
'sankey': 'Sankey',
'scatter': 'ScatterChart',
'md-scatter': 'google.charts.Scatter',
'stepped-area': 'SteppedAreaChart',
'table': 'Table',
'timeline': 'Timeline',
'treemap': 'TreeMap',
'wordtree': 'WordTree',
};
/**
* `google-chart` encapsulates Google Charts as a web component, allowing you to
* easily visualize data. From simple line charts to complex hierarchical tree
* maps, the chart element provides a number of ready-to-use chart types.
*
* ```html
* <google-chart
* type='pie'
* options='{"title": "Distribution of days in 2001Q1"}'
* cols='[{"label":"Month", "type":"string"}, {"label":"Days",
* "type":"number"}]' rows='[["Jan", 31],["Feb", 28],["Mar", 31]]'>
* </google-chart>
* ```
*
* Note: if you're passing JSON as attributes, single quotes are necessary to be
* valid JSON. See
* https://www.polymer-project.org/1.0/docs/devguide/properties#configuring-object-and-array-properties.
*
* Height and width are specified as style attributes:
* ```css
* google-chart {
* height: 300px;
* width: 50em;
* }
* ```
*
* Data can be provided in one of three ways:
*
* - Via the `cols` and `rows` attributes:
* ```
* cols='[{"label":"Mth", "type":"string"},{"label":"Days", "type":"number"}]'
* rows='[["Jan", 31],["Feb", 28],["Mar", 31]]'
* ```
*
* - Via the `data` attribute, passing in the data directly:
* ```
* data='[["Month", "Days"], ["Jan", 31], ["Feb", 28], ["Mar", 31]]'
* ```
*
* - Via the `data` attribute, passing in the URL to a resource containing the
* data, in JSON format:
* ```
* data='http://example.com/chart-data.json'
* ```
*
* - Via the `data` attribute, passing in a Google DataTable object:
* ```
* data='{{dataTable}}'
* ```
*
* - Via the `view` attribute, passing in a Google DataView object:
* ```
* view='{{dataView}}'
* ```
*
* You can display the charts in locales other than "en" by setting the `lang`
* attribute on the `html` tag of your document:
* ```
* <html lang="ja">
* ```
*
* @demo demo/index.html
*/
export class GoogleChart extends LitElement {
/** @nocollapse */
static override styles = css`
:host {
display: -webkit-flex;
display: -ms-flex;
display: flex;
margin: 0;
padding: 0;
width: 400px;
height: 300px;
}
:host([hidden]) {
display: none;
}
:host([type="gauge"]) {
width: 300px;
height: 300px;
}
#chartdiv {
width: 100%;
}
/* Workaround for slow initial ready event for tables. */
.google-visualization-table-loadtest {
padding-left: 6px;
}
`;
/**
* Fired after a chart type is rendered and ready for interaction.
*
* @event google-chart-ready
* @param {{chart: !Object}} detail The raw chart object.
*/
/**
* Fired when the user makes a selection in the chart.
*
* @event google-chart-select
* @param {{chart: !Object}} detail The raw chart object.
*/
/**
* Type of the chart.
*
* Should be one of:
* - `area`
* - `(md-)bar`
* - `bubble`
* - `calendar`
* - `candlestick`
* - `column`
* - `combo`
* - `gantt`
* - `gauge`
* - `geo`
* - `histogram`
* - `(md-)line`
* - `org`
* - `pie`
* - `sankey`
* - `(md-)scatter`
* - `stepped-area`
* - `table`
* - `timeline`
* - `treemap`
* - `wordtree`
*
* See <a
* href="https://google-developers.appspot.com/chart/interactive/docs/gallery">Google
* Visualization API reference (Chart Gallery)</a> for details.
*/
@property({type: String, reflect: true})
type = 'column';
/**
* Enumerates the chart events that should be fired.
*
* Charts support a variety of events. By default, this element only
* fires on `ready` and `select`. If you would like to be notified of
* other chart events, use this property to list them.
* Events `ready` and `select` are always fired.
*
* Changes to this property are _not_ observed. Events are attached only
* at chart construction time.
*/
@property({type: Array})
events: string[] = [];
/**
* Sets the options for the chart.
*
* Example:
* ```
* {
* title: "Chart title goes here",
* hAxis: {title: "Categories"},
* vAxis: {title: "Values", minValue: 0, maxValue: 2},
* legend: "none"
* }
* ```
* See <a
* href="https://google-developers.appspot.com/chart/interactive/docs/gallery">Google
* Visualization API reference (Chart Gallery)</a> for the options available
* to each chart type.
*
* Setting this property always redraws the chart. If you would like to make
* changes to a sub-property, be sure to reassign the property:
* ```
* const options = googleChart.options;
* options.vAxis.logScale = true;
* googleChart.options = options;
* ```
* (Note: Missing parent properties are not automatically created.)
*/
@property({type: Object, hasChanged: () => true})
options: {}|undefined = undefined;
/**
* Sets the data columns for this object.
*
* When specifying data with `cols` you must also specify `rows`, and
* not specify `data`.
*
* Example:
* <pre>[{label: "Categories", type: "string"},
* {label: "Value", type: "number"}]</pre>
* See <a
* href="https://google-developers.appspot.com/chart/interactive/docs/reference#DataTable_addColumn">Google
* Visualization API reference (addColumn)</a> for column definition format.
*/
@property({type: Array})
cols: unknown[]|undefined = undefined;
/**
* Sets the data rows for this object.
*
* When specifying data with `rows` you must also specify `cols`, and
* not specify `data`.
*
* Example:
* <pre>[["Category 1", 1.0],
* ["Category 2", 1.1]]</pre>
* See <a
* href="https://google-developers.appspot.com/chart/interactive/docs/reference#addrow">Google
* Visualization API reference (addRow)</a> for row format.
*/
@property({type: Array})
rows: unknown[][]|undefined = undefined;
/**
* Sets the entire dataset for this object.
* Can be used to provide the data directly, or to provide a URL from
* which to request the data.
*
* The data format can be a two-dimensional array or the DataTable format
* expected by Google Charts.
* See <a
* href="https://google-developers.appspot.com/chart/interactive/docs/reference#DataTable">Google
* Visualization API reference (DataTable constructor)</a> for data table
* format details.
*
* When specifying data with `data` you must not specify `cols` or `rows`.
*
* Example:
* ```
* [["Categories", "Value"],
* ["Category 1", 1.0],
* ["Category 2", 1.1]]
* ```
*/
// Note: type: String, because it is parsed manually in the observer.
@property({type: String})
data: DataTableLike|string|undefined = undefined;
/**
* Sets the entire dataset for this object to a Google DataView.
*
* See <a
* href="https://google-developers.appspot.com/chart/interactive/docs/reference#dataview-class">Google
* Visualization API reference (DataView)</a> for details.
*
* When specifying data with `view` you must not specify `data`, `cols` or
* `rows`.
*/
@property({type: Object})
view: google.visualization.DataView|undefined = undefined;
/**
* Selected datapoint(s) in the chart.
*
* An array of objects, each with a numeric row and/or column property.
* `row` and `column` are the zero-based row or column number of an item
* in the data table to select.
*
* To select a whole column, set row to null;
* to select a whole row, set column to null.
*
* Example:
* ```
* [{row:0,column:1}, {row:1, column:null}]
* ```
*/
@property({type: Array})
selection: google.visualization.ChartSelection[]|undefined = undefined;
/**
* Whether the chart is currently rendered.
* @export
*/
drawn = false;
/**
* Internal data displayed on the chart.
*/
// tslint:disable-next-line:enforce-name-casing
@property({type: Object}) _data: google.visualization.DataTable|
google.visualization.DataView|undefined = undefined;
/**
* Internal chart object.
*/
private chartWrapper: google.visualization.ChartWrapper|null = null;
private redrawTimeoutId: number|undefined = undefined;
protected override render() {
return html`
<div id="styles"></div>
<div id="chartdiv"></div>
`;
}
protected override firstUpdated() {
createChartWrapper(this.shadowRoot!.getElementById('chartdiv')!)
.then(chartWrapper => {
this.chartWrapper = chartWrapper;
this.typeChanged();
google.visualization.events.addListener(chartWrapper, 'ready', () => {
this.drawn = true;
if (this.selection) {
this.selectionChanged();
}
});
google.visualization.events.addListener(
chartWrapper, 'select', () => {
this.selection = chartWrapper.getChart()!.getSelection();
});
this.propagateEvents(DEFAULT_EVENTS, chartWrapper);
});
}
protected override updated(changedProperties: Map<string, unknown>) {
if (changedProperties.has('type')) this.typeChanged();
if (changedProperties.has('rows') || changedProperties.has('cols')) {
this.rowsOrColumnsChanged();
}
if (changedProperties.has('data')) this.dataChanged();
if (changedProperties.has('view')) this.viewChanged();
if (changedProperties.has('_data') ||
changedProperties.has('options')) this.redraw();
if (changedProperties.has('selection')) this.selectionChanged();
}
/** Reacts to chart type change. */
private typeChanged() {
if (this.chartWrapper == null) return;
this.chartWrapper.setChartType(CHART_TYPES[this.type] || this.type);
const lastChart = this.chartWrapper.getChart();
google.visualization.events.addOneTimeListener(
this.chartWrapper, 'ready', () => {
// Ready event fires after `chartWrapper` is initialized.
const chart = this.chartWrapper!.getChart();
if (chart !== lastChart) {
this.propagateEvents(
this.events.filter(
(eventName) => !DEFAULT_EVENTS.includes(eventName)),
chart);
}
const stylesDiv = this.shadowRoot!.getElementById('styles')!;
if (!stylesDiv.children.length) {
this.localizeGlobalStylesheets(stylesDiv);
}
});
this.redraw();
}
/**
* Adds listeners to propagate events from the chart.
*/
private propagateEvents(events: string[], eventTarget: unknown) {
for (const eventName of events) {
google.visualization.events.addListener(
eventTarget, eventName, (event: unknown) => {
this.dispatchEvent(new CustomEvent(`google-chart-${eventName}`, {
bubbles: true,
composed: true,
detail: {
// Events fire after `chartWrapper` is initialized.
chart: this.chartWrapper!.getChart(),
data: event,
}
}));
});
}
}
/** Sets the selectiton on the chart. */
private selectionChanged() {
if (this.chartWrapper == null) return;
const chart = this.chartWrapper.getChart();
if (chart == null) return;
if (chart.setSelection) {
// Workaround for timeline chart which emits select event on setSelection.
// See issue #256.
if (this.type === 'timeline') {
const oldSelection = JSON.stringify(chart.getSelection());
const newSelection = JSON.stringify(this.selection);
if (newSelection === oldSelection) return;
}
chart.setSelection(this.selection);
}
}
/**
* Redraws the chart.
*
* Called automatically when data/type/selection attributes change.
* Call manually to handle view updates, page resizes, etc.
*/
redraw() {
if (this.chartWrapper == null || this._data == null) return;
// `ChartWrapper` can be initialized with `DataView` instead of `DataTable`.
this.chartWrapper.setDataTable(
this._data as google.visualization.DataTable);
this.chartWrapper.setOptions(this.options || {});
this.drawn = false;
if (this.redrawTimeoutId !== undefined) clearTimeout(this.redrawTimeoutId);
this.redrawTimeoutId = window.setTimeout(() => {
// Drawing happens after `chartWrapper` is initialized.
this.chartWrapper!.draw();
}, 5);
}
/**
* Returns the chart serialized as an image URI.
*
* Call this after the chart is drawn (`google-chart-ready` event).
*/
get imageURI(): string|null {
if (this.chartWrapper == null) return null;
const chart = this.chartWrapper.getChart();
return chart && (chart as google.visualization.ChartBaseRenderable).getImageURI();
}
/** Handles changes to the `view` attribute. */
private viewChanged() {
if (!this.view) return;
this._data = this.view;
}
/** Handles changes to the rows & columns attributes. */
private async rowsOrColumnsChanged() {
const {rows, cols} = this;
if (!rows || !cols) return;
try {
const dt = await dataTable({cols});
dt.addRows(rows);
this._data = dt;
} catch (reason) {
this.shadowRoot!.getElementById('chartdiv')!.textContent = String(reason);
}
}
/**
* Handles changes to the `data` attribute.
*/
private dataChanged() {
let data = this.data;
let dataPromise;
if (!data) {
return;
}
let isString = false;
// Polymer 2 will not call observer if type:Object is set and fails, so
// we must parse the string ourselves.
try {
// Try to deserialize the value of the `data` property which might be a
// serialized array.
data = JSON.parse(data as string) as DataTableLike;
} catch (e) {
isString = typeof data === 'string' || data instanceof String;
}
if (isString) {
// Load data asynchronously, from external URL.
dataPromise = fetch(data as string).then(response => response.json());
} else {
// Data is all ready to be processed.
dataPromise = Promise.resolve(data);
}
dataPromise.then(dataTable).then(data => {
this._data = data;
});
}
/**
* Queries global document head for Google Charts `link#load-css-*` and clones
* them into the local root's `div#styles` element for shadow dom support.
*/
private localizeGlobalStylesheets(stylesDiv: HTMLElement) {
// Get all Google Charts stylesheets.
const stylesheets = Array.from(document.head.querySelectorAll(
'link[rel="stylesheet"][type="text/css"][id^="load-css-"]'));
for (const stylesheet of stylesheets) {
// Clone necessary stylesheet attributes.
const clonedStylesheet = document.createElement('link');
clonedStylesheet.setAttribute('rel', 'stylesheet');
clonedStylesheet.setAttribute('type', 'text/css');
// `href` is always present.
clonedStylesheet.setAttribute('href', stylesheet.getAttribute('href')!);
stylesDiv.appendChild(clonedStylesheet);
}
}
}
customElements.define('google-chart', GoogleChart);
declare global {
interface HTMLElementTagNameMap {
'google-chart': GoogleChart;
}
}