In UIWebView, fetch is buggy inside onfocus, it may just be silent and call neither callback.
open demo page : https://weiying-shenzhen.github.io/UIWebview-BUG-fetch-silence-when-foucs/ ,
focus on input, and blur
and do above line again
results:
| chrome | ios UIWebView |
|---|---|
 |
 |
clearly ios UIWebView is lack of 3 done log after second focus. (no error log either)
the 3 fetch at second focus seem just silent after start, neither success nor error callback is triggered.
iOS 10.3, 10.3.1 and 10.3.2, earlier version not tested.
Not occurs on WKWebView
- 发现过程
发现手Q在输入框 focus 时调用原生 fetch 获取数据，有大概率会出现数据返回但没有触发 fetch 回调的情况
后经过对比和其他程序测试，认为是UIWebview的bug
- 复现环境
IOS版本：10.3.1
手Q版本：v7.0.1.407
- 复现步骤
1. 使用手Q打开[示例页面](https://weiying-shenzhen.github.io/UIWebview-BUG-fetch-silence-when-foucs/)
2. 点击页面的输入框触发 focus 和 fetch
3. 符合复现环境的机型，会停留在 fetch start，但后端数据其实已经返回了