Sandboxed visuals' data sometimes gets mixed up in Google Chrome.
Background:
I had a report containing two instances of one of my custom visuals. Yesterday I noticed that sometimes when I enter the report/refresh the browser in Chrome, at least one of them shows no data. In order to determine the source of the problem, I performed the tests listed below.
Tests:
I performed the following tests in Chrome(Versions 50.0.2661.87 & one from the 49.x.xxxx.xx series), Firefox, Edge, IE11 and Chromium(Version 49.0.2623.108 64-bit). The issue was encountered only in Chrome, and in both versions.
1. I went to the page of my original report and started refreshing it every time it finished loading. In some occasions, at least one of the visuals did not show any data.
2. I removed one of the visuals from the page, saved it and performed the 1st test again. This time, I did not encounter this issue.
3. I duplicated the remaining visual from the 2nd test, moved and resized it(without changing its data), saved the report and started refreshing. On some occasions, one visual did not display any data, and the other one not only shown the first one's data, but actually had its content resized to the size of the first visual.
I later changed the data of the second visual, and still got the same results.
4. I created a new report with static data, imported an unmodified version of the "YourVisual" visual exported from the DevTools, put two instances of it on the page(each with different data), published it to Power BI Service, went to the page and started refreshing. In some occasions, one of them showed no data, and the other showed the former's content, much like in the 3rd test.
5. I imported another version of "YourVisual", modified to have a different background color, to the report from the 4th test, added one instance of it to the page, and performed the refreshing ritual yet again. This time, I encountered even weirder results, where one visual showed no data, the second visual showed the correct data and the third visual showed a wierd mashup of its own data and the data of the first visual(It showed its own category names and the first one's values, to be exact).
Additional Information:
1. I encountered this issue more frequently when I used my own visuals. I think the reason is that my visual takes longer to load.
2. As stated before, this issue was encountered only in sandboxing mode.
Conclusions:
1. Tests 4 and 5 suggest that the issue is not caused by a faulty visual implementation.
2. The fact that how the content is displayed is also affected by this issue suggests that each affected visual's update() method gets the wrong VisualUpdateOptions object, and not just the wrong DataView object.
3. There are some similarities between this issue and the one reported in my previous post. Both cause a data mix-up, both happen right after the visual is initialized and both seem to be affected by the visuals' loading time. The previous issue, however, occurs in all browsers and much more frequently.