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File Upload

WdUploadFile

Applicable Scenarios​

For uploading local file resources, such as video, audio, PDF, Excel, Word, and other file types.

Basic Capabilities​

Binding "File, Array" Fields​

  1. Single file upload: After the form container is bound to the data model, the "File" field in the model is automatically rendered as a file upload component, enabling support for single file upload.
  2. Multiple file upload: After the form container is bound to the data model, the "Array" field of image type in the model is automatically rendered as a file upload component, enabling support for multiple file uploads.

Extended Scenarios​

Get the File ID After User Upload​

After a file is uploaded via the file upload component, the "Upload Success" event is triggered. The cloudID of the uploaded file can be obtained from the event.detail.value parameter of this event. This ID can be viewed by printing logs, as shown in the following example:

  1. Create a custom method and write the log printing code console.log(event.detail.value). The specific content format is as shown in the figure below:

  2. Drag and drop the "File Upload" component into the page, and configure the "Upload Success" event to trigger this log printing method.

  3. Preview the configuration effect: you will find that after the file is uploaded successfully, the cloudID of the uploaded file will be printed in the console.

  4. In daily use, you can store this ID in a variable through the component's upload success event, or utilize it in other ways.

Other Scenario Practices​

Refer to the Form Scenario Practice Guide to learn about various supported scenarios and implementation solutions for forms.

Notes​

caution

After a file is uploaded, it is downloadable by the logged-in user by default. For security reasons, the generated temporary download URL has a time limit and is not recommended for storage in databases. To restrict file/image resources to be downloadable only by the uploader, adjust the bucket access permission to "Only creator and administrator have read-write access" in the Cloud Development - Cloud Storage module of the WeDa environment.

Example​

Interactive Preview​

Component Input State​

Style API Example​

#wd-page-root .wd-form-item.wd-pc-upload-file-root .wd-upload-file__label {
  color: #05c3c3;
  display: flex;
  justify-content: center;
  align-items: center;
}
#wd-page-root
  .wd-form-item.wd-pc-upload-file-root
  .weda-upload-file-pc__btn--weak {
  background: transparent;
}

Properties​

组件接收的外部传入的属性

属性名
属性标识
类型
说明
显示标题labelVisibleboolean

默认值：true

标题对齐labelAlignstring

表单场景下默认会跟随表单容器的标题对齐配置

标题换行labelWrapboolean

如果标题内容过长关闭时只显示一行、溢出省略；开启时换行展示。表单场景下默认会跟随表单容器的标题换行配置

标题位置layoutstring

设置标题在表单组件的展示位置，表单场景下默认会跟随表单容器的标题的位置配置

标题宽度labelWidthstring

您可以输入数值 + px、%等单位，示例：200px

表单场景下默认会跟随表单容器的标题宽度配置

标题提示labelTipsstring

PC/H5端生效

配置标题的工具提示内容

单个文件最大限制(M)maxSizenumber

默认值：10

文件类型限制acceptTypesstring

为空表示不做限制；多个类型之间请用英文逗号分隔，如 doc,pdf,png；该属性暂不支持小程序。

支持上传的文件类型格式

文件数量上限maxUploadCountnumber

允许上传的最大数量

默认值：9

状态statusstring

示例："edit"

必填requiredboolean
必填标识requiredFlagboolean

启用后，组件若要求必填，则会显示必填星号标记

默认值：true

必填校验提示requiredMsgstring

示例："该项为必填项"

上传按钮文案uploadButtonTextstring

上传按钮文案

默认值："点击上传"

批量上传描述uploadTipTextstring

支持批量上传时的文案描述

默认值："支持批量上传"

下方提示extrastring

配置后提示内容常显在输入框下方

上传后支持下载downloadVisibleboolean

默认值：true

上传后支持删除deleteVisibleboolean

默认值：true

移动端显示下划线borderedH5boolean

关闭后移动端不显示底部下划线

默认值：true

callbacksobject

配置相关的函数

绑定字段namestring

文件上传后，文件 https 链接默认仅可在微搭应用中访问，有效期 2 小时，可在云存储权限设置中调整访问权限。

表单字段的Key值，用于提交数据时，匹配数据模型字段标识。表单内需保证唯一。

标题内容labelstring

示例："文件上传"

值存储方式storageTypestring

选择cloudID方式，文件将以云存储 fileID 的形式直接存储在数据模型中；选择https方式，需先开启云存储公有读写权限，文件将以https链接形式存储在数据模型中。

指定图片存储方式

默认值："cloudID"

文件值valuearray

支持以数组格式写入文件的https地址或cloudID；上传单个时支持字符串类型，上传多个时支持数组类型

上传单个文件singleboolean

如需上传多个文件，可关闭该属性，但需绑定数组-文件字段，以保证表单的正常提交 了解详情

开启小程序端获取微信头像后，仅能上传1张图片

Pre-upload Handler Function Property​

The uploaded files can be preprocessed via the pre-upload handler function.

Function Input Parameter Type:

type BeforeUploadParams0 = {
  // base64 uri
  base64Uri: string[];
  // Exclusive to the Mini Program side, temporary file address.
  tempFilePaths?: string[];
  // Exclusive to the web side, File object
  files: File[];
};

Function return value type:

boolean | File[] | string[]
  • Returns true to continue the default upload logic.
  • Returns false to disable the default upload logic.
  • The web side returns a File array. The web side receives the file[] returned by the function as upload objects to complete the upload logic.
  • The Mini Program side returns a string[] temporary file address array. The Mini Program side receives the temporary file address array returned by the function as upload objects to complete the upload logic.

The application runtime can determine via the Platform API to refine multi-end custom upload logic.

Example: Custom Upload​

For example, to customize uploading to another location such as COS. Below, using CloudBase Cloud Storage within the WeDa environment as an example:

async (result) => {
  console.log('beforeUpload', result);
  // Can be processed before upload, such as compression
  // result.files[0] = FAKE_COMPRESS(result.files[0])

  const tcb = await $w.cloud.getCloudInstance();
  const res = await tcb.uploadFile({
    cloudPath: 'ttt/abc.jpg',
    filePath: result.files[0]
  });

  console.log(res.download_url); // Image HTTP address
  $w.uploadImage1.setValue({ value: [res.download_url] }); // Set the obtained http address to the image upload component
  return false; // Abort the upload
};

Events​

组件暴露的事件，可以监听组件的事件来触发一些外部的动作

事件名
事件code
事件出参 event.detail
适用情况
说明
值改变changeobject
  • value: 值
  • isDelete: boolean是否删除动作
兼容三端

用户修改组件值时触发

上传成功successobject
  • value:

    上传文件的fileId
  • file:

    上传文件file对象
兼容三端

-

上传失败error兼容三端

-

Property API​

通过属性 API，可以获取组件内部的状态和属性值，可以通过$w.componentId.propertyName 来访问组件内部的值，如 $w.input1.value ，详请请参考 属性 API

只读属性名
属性标识
类型
说明
绑定字段namestring

表单字段的Key值，用于提交数据时，匹配数据模型字段标识。表单内需保证唯一。

标题内容labelstring
文件值valuearray

支持以数组格式写入文件的https地址或cloudID；上传单个时支持字符串类型，上传多个时支持数组类型

必填requiredboolean
是否展示visibleboolean

组件是否展示

是否禁用disabledboolean

组件是否禁用

是否只读readOnlyboolean

组件是否只读

Method API​

通过方法 API，可以通过程序触发组件内部的方法，比如提交表单，显示弹窗等, 可以通过$w.componentId.methodName来调用组件方法，如 $w.form1.submit()

方法名
方法标识
参数
方法说明
设置值setValueobject
  • value: 值
  • isDelete: boolean是否删除动作

通过 $w.id1.setValue("weda") 设置组件值

设置显隐setVisibleboolean显示

通过 $w.id1.setVisible(false) 设置组件为隐藏

设置禁用setDisabledboolean禁用

通过 $w.id1.setDisabled(true) 设置组件为禁用

清空值clearValue

通过 $w.id1.clearValue() 清空组件值

设置只读setReadOnlyboolean只读

通过 $w.id1.setReadOnly(true) 设置组件为只读

触发校验handleValidate

通过 $w.id1.handleValidate() 校验组件值

清除校验clearValidate

通过 $w.id1.clearValidate() 清除组件校验

Style API​

通过样式 API，可以覆盖组件中内部元素的样式来实现自定义，例如在低代码编辑器中中通过 #wd-page-root .wd-btn 即可为所有的按钮组件编写样式，通过 :scope 可以控制单个组件样式， 详细说明请参考样式 API

名称
类名
说明和示例
根元素.wd-upload-file-root组件最外层元素
/* :scope 指的是当前组件元素 */
/* 具体可参考样式 API 文档 */
:scope.wd-upload-file-root {
  /* 在这里编写CSS 样式 */
}
H5 端根元素.wd-h5-upload-file-root可设定 H5 端的根元素样式
/* :scope 指的是当前组件元素 */
/* 具体可参考样式 API 文档 */
:scope.wd-h5-upload-file-root {
  /* 在这里编写CSS 样式 */
}
PC 端根元素.wd-pc-upload-file-root可设定 PC 端的根元素样式
/* :scope 指的是当前组件元素 */
/* 具体可参考样式 API 文档 */
:scope.wd-pc-upload-file-root {
  /* 在这里编写CSS 样式 */
}
小程序端根元素.wd-mp-upload-file-root可设定小程序端的根元素样式
/* :scope 指的是当前组件元素 */
/* 具体可参考样式 API 文档 */
:scope.wd-mp-upload-file-root {
  /* 在这里编写CSS 样式 */
}
组件标题样式.wd-upload-file-root .wd-form-item-wrap__label组件标题元素

:scope .wd-form-item-wrap__label {
  font-size: 20px;
  color: gray;
  padding: 0;
  display: flex;
  align-items: center;
}
表单控件根节点样式.wd-upload-file-root .wd-form-item-wrap__control设置表单控件根元素样式

:scope .wd-form-item-wrap__control {
  font-size: 20px;
  color: gray;
  padding: 0;
  display: flex;
  align-items: center;
}
编辑态-校验信息.wd-upload-file-root .wd-g-text-error设置组件校验信息样式

:scope .wd-g-text-error {
    font-size: 20px;
    color: gray;
  }
提示文字.wd-upload-file-root .wd-form-item__help-text设置组件提示文字样式

:scope .wd-form-item__help-text {
    font-size: 20px;
    color: gray;
  }

了解样式 API

Version Changes​

  • Property changes
  • Style changes
  • widget api changes

Frequently Asked Questions​

Is there a limit on the file size for uploads?​

The size limit for file uploads primarily depends on the limitations of the underlying cloud storage. Currently, the PUT Object interface of the underlying cloud storage supports uploading files of up to 5GB. Although there is no strict limit, excessively large files tend to cause upload failures because the feature for resumable uploads is not yet supported. In practical applications, please select an appropriate file size for upload based on actual requirements and network conditions.

What file formats are supported for Mini Program file downloads?​

On the Mini Program side, file preview and download are implemented via the wx.openDocument interface, which only supports downloading files in specific formats.

image