[new feature] Uploader: support isImage flag (#4072)

src/uploader/README.zh-CN.md

@@ -42,7 +42,10 @@ export default {
   data() {
     return {
       fileList: [
-        { url: 'https://img.yzcdn.cn/vant/cat.jpeg' }
+        { url: 'https://img.yzcdn.cn/vant/cat.jpeg' },
+        // Uploader 根据文件后缀来判断是否为图片文件
+        // 如果图片 URL 中不包含类型信息，可以添加 isImage 标记来声明
+        { url: 'https://cloud-image', isImage: true }
       ]
     }
   }

src/uploader/test/utils.spec.js

@@ -10,5 +10,6 @@ test('isImageFile', () => {
   expect(isImageFile({ file: { type: 'application/pdf' } })).toBeFalsy();
   expect(isImageFile({ content: 'data:image/xxx' })).toBeTruthy();
   expect(isImageFile({ content: 'data:application/xxx' })).toBeFalsy();
+  expect(isImageFile({ isImage: true })).toBeTruthy();
   expect(isImageFile({})).toBeFalsy();
 });

src/uploader/utils.ts

@@ -30,6 +30,7 @@ export type FileListItem = {
   url?: string;
   file?: File;
   content?: string; // dataUrl
+  isImage?: boolean;
 };
 
 const IMAGE_EXT = ['jpeg', 'jpg', 'gif', 'png', 'svg'];
@@ -39,6 +40,12 @@ export function isImageUrl(url: string): boolean {
 }
 
 export function isImageFile(item: FileListItem): boolean {
+  // some special urls cannot be recognized
+  // user can add `isImage` flag to mark it as an image url
+  if (item.isImage) {
+    return true;
+  }
+
   if (item.file && item.file.type) {
     return item.file.type.indexOf('image') === 0;
   }