feat(slider): fix incorrect dot pos caused by repeated init (Tencent#3085)

* feat(slider): fix incorrect dot pos caused by repeated init

each time init is called, the dots are set to the defaultValue position. Added a flag to filter

fix Tencent#3083

* docs(slider): update readme

Author: jby0107

src/slider/README.md

@@ -101,7 +101,7 @@ t-class-cursor | 游标样式类
 
 ## FAQ
 
-当 slider 外层使用 `hidden` 包裹，需要在 `hidden = false` 时，重新调用组件的 `init` 方法，才能正常渲染。如下：
+当 slider 外层使用 `hidden` 包裹，需要在 `hidden = false` 时，重新调用组件的 `init` 方法，才能正常渲染（在t-popup/t-dialog中同理）。如下：
 
 ```html
 <t-slider id="slider" />

src/slider/slider.ts

@@ -28,6 +28,7 @@ type dataType = {
   prefix: string;
   isVisibleToScreenReader: boolean;
   identifier: number[];
+  __inited: boolean;
 };
 
 interface boundingClientRect {
@@ -46,6 +47,10 @@ export default class Slider extends SuperComponent {
     `${prefix}-class-cursor`,
   ];
 
+  options = {
+    pureDataPattern: /^__/,
+  };
+
   properties = props;
 
   controlledProps = [
@@ -76,6 +81,7 @@ export default class Slider extends SuperComponent {
     prefix,
     isVisibleToScreenReader: false,
     identifier: [-1, -1],
+    __inited: false,
   };
 
   observers = {
@@ -218,6 +224,7 @@ export default class Slider extends SuperComponent {
   }
 
   async init() {
+    if (this.data.__inited) return;
     const line: boundingClientRect = await getRect(this, '#sliderLine');
     const { blockSize } = this.data;
     const { theme, vertical } = this.properties;
@@ -238,6 +245,7 @@ export default class Slider extends SuperComponent {
       maxRange,
       initialLeft,
       initialRight,
+      __inited: true,
     });
     this.bus.emit('initial');
   }