2 * @fileoverview Utility functions for Dygraphs.
4 * @author konigsberg@google.com (Robert Konigsberg)
9 * Get the y-labels for a given axis.
11 * You can specify a parent if more than one graph is in the document.
13 Util
.getYLabels
= function(axis_num
, parent
) {
14 axis_num
= axis_num
|| "";
15 parent
= parent
|| document
;
16 var y_labels
= parent
.getElementsByClassName("dygraph-axis-label-y" + axis_num
);
18 for (var i
= 0; i
< y_labels
.length
; i
++) {
19 ary
.push(y_labels
[i
].innerHTML
.replace(/ | /g, ' '));
25 * Get the x-labels for a given axis.
27 * You can specify a parent if more than one graph is in the document.
29 Util
.getXLabels
= function(parent
) {
30 parent
= parent
|| document
;
31 var x_labels
= parent
.getElementsByClassName("dygraph-axis-label-x");
33 for (var i
= 0; i
< x_labels
.length
; i
++) {
34 ary
.push(x_labels
[i
].innerHTML
.replace(/ | /g, ' '));
40 * Returns all text in tags w/ a given css class, sorted.
41 * You can specify a parent if more than one graph is on the document.
43 Util
.getClassTexts
= function(css_class
, parent
) {
44 parent
= parent
|| document
;
46 var els
= parent
.getElementsByClassName(css_class
);
47 for (var i
= 0; i
< els
.length
; i
++) {
48 texts
[i
] = els
[i
].textContent
;
54 Util
.getLegend
= function(parent
) {
55 parent
= parent
|| document
;
56 var legend
= parent
.getElementsByClassName("dygraph-legend")[0];
57 var re
= new RegExp(String
.fromCharCode(160), 'g');
58 return legend
.textContent
.replace(re
, ' ');
62 * Assert that all elements have a certain style property.
64 Util
.assertStyleOfChildren
= function(selector
, property
, expectedValue
) {
65 assert
.isTrue(selector
.length
> 0);
66 for (var idx
= 0; idx
< selector
.length
; idx
++) {
67 var child
= selector
[idx
];
68 assert
.equal(expectedValue
, window
.getComputedStyle(child
)[property
]);
74 * Takes in an array of strings and returns an array of floats.
76 Util
.makeNumbers
= function(ary
) {
78 for (var i
= 0; i
< ary
.length
; i
++) {
79 ret
.push(parseFloat(ary
[i
]));
86 * Sample a pixel from the canvas.
87 * Returns an [r, g, b, a] tuple where each values is in [0, 255].
89 Util
.samplePixel
= function(canvas
, x
, y
) {
90 var ctx
= canvas
.getContext("2d"); // bypasses Proxy if applied.
92 // TODO(danvk): Any performance issues with this?
93 var imageData
= ctx
.getImageData(0, 0, canvas
.width
, canvas
.height
);
95 var scale
= Dygraph
.getContextPixelRatio(ctx
);
97 var i
= 4 * (x
* scale
+ imageData
.width
* y
* scale
);
98 var d
= imageData
.data
;
99 return [d
[i
], d
[i
+1], d
[i
+2], d
[i
+3]];
103 * Overrides the browser's built-in XMLHttpRequest with a mock.
106 * var mockXhr = Util.overrideXMLHttpRequest(your_data);
107 * ... call code that does an XHR ...
108 * mockXhr.respond(); // restores default behavior.
109 * ... do your assertions ...
111 Util
.overrideXMLHttpRequest
= function(data
) {
112 var originalXMLHttpRequest
= XMLHttpRequest
;
115 var FakeXMLHttpRequest
= function () {
118 FakeXMLHttpRequest
.prototype.open
= function () {};
119 FakeXMLHttpRequest
.prototype.send
= function () {
122 this.responseText
= data
;
124 FakeXMLHttpRequest
.restore
= function() {
125 window
.XMLHttpRequest
= originalXMLHttpRequest
;
127 FakeXMLHttpRequest
.respond
= function() {
128 for (var i
= 0; i
< requests
.length
; i
++) {
129 requests
[i
].onreadystatechange();
131 FakeXMLHttpRequest
.restore();
133 window
.XMLHttpRequest
= FakeXMLHttpRequest
;
134 return FakeXMLHttpRequest
;
138 * Format a date as 2000/01/23
139 * @param {number} dateMillis Millis since epoch.
140 * @return {string} The date formatted as YYYY-MM-DD.
142 Util
.formatDate
= function(dateMillis
) {
143 return Dygraph
.dateString_(dateMillis
).slice(0, 10); // 10 == "YYYY/MM
/DD
".length