React/Redux 下载文件 [英] React/Redux download file

问题描述

我需要在单击按钮时从服务器下载文件.

我创建了一个 MaterialUI 按钮，在它的 onclick 回调中，我调用了容器组件 connected 的一个动作.

该操作是异步的并执行 ajax POST:

export const onXlsxClick = () =>调度 =>{const urlParams = {过滤器:{聚合:'macro_area'，图表分辨率:'1_小时'，chart_from: '1478080363',chart_to: '1477993963'},标签:['PROVA1'，'PROVA2']，系列: [{标签:空，时间戳:1478080363，值:[123, 345]},{标签:空，时间戳:1477993963，值:[153, 3435]}]};返回 $.ajax({url:'/rest/export/chart/xlsx',类型:'POST'，数据类型:'应用程序/json'，内容类型:'应用程序/json'，数据:JSON.stringify(urlParams)}).完成(数据=> {console.log('成功');}). 失败(错误 => {控制台日志(错误)；});};

服务器接收请求并通过此 REST 服务正确处理它:

@POST@Path("xlsx")@Produces("application/vnd.ms-excel")公共响应 getXlsx(ChartExportRequest 请求){ResponseBuilder responseBuilder;ChartExportRequestDTO reqDto = null;尝试 {reqDto = parseDTO(请求)；checkRequestDTO(reqDto);ExportDTO dto = getXlsxProvider().create(reqDto);responseBuilder = Response.ok(dto.getFile()).header("Content-disposition", "attachment;filename=" + dto.getFileName());}捕获(异常 e){logger.error("为带有请求 [" + (reqDto != null ? reqDto.toString() : null) + "]" 的标签 RIGEDI 提供导出 xlsx 时出错，e);responseBuilder = Response.serverError().entity(e.getMessage());}返回 responseBuilder.build();}

问题是响应正确到达客户端，但没有任何反应:我希望浏览器显示下载对话框(例如:在 chrome 中，我希望下载的底部栏与我的文件一起出现).

我做错了什么?

解决方案

AS per Nate's answer 这里，Ajax 请求的响应不被浏览器识别为文件.对于所有 Ajax 响应，它的行为方式相同.您需要手动触发下载弹出窗口.

在我的实现中，我使用 filesaverjs 触发下载弹出窗口，一旦我收到减速器中的 API 响应.

由于 FileSaver 使用 blob 来保存文件，我将来自服务器的响应作为 blob 发送，将其转换为字符串数组缓冲区，然后使用它来保存我的文件.

中描述了这种方法

请在下面找到减速器的示例代码:(根据 Redux，使用 reducer 进行状态修改)减速器.js

let fileSaver = require("file-saver");导出默认函数 projectReducer(state = {}, action){让项目；开关(动作.类型){案例 GET_PROJECT_SUCCESS :项目 = Object.assign(action.response.data);回归项目；案例 EXPORT_AND_DOWNLOAD_DATA_SUCCESS :让数据 = s2ab(action.response.data);fileSaver.saveAs(new Blob([data], {type: "application/octet-stream"}), "test.xlsx");返回状态；}返回状态；}函数 s2ab(s) {var buf = new ArrayBuffer(s.length);var view = new Uint8Array(buf);for (var i = 0; i != s.length; ++i) {视图[i] = s.charCodeAt(i) &0xFF;}返回缓冲区；}

I need to download a file from the server when a button is clicked.

I created a MaterialUI button and on its onclick callback i call an action of the container component connected.

The action is asynchronous and does an ajax POST:

export const onXlsxClick = () => dispatch => {
    const urlParams = {
        filters: {
            aggregation: 'macro_area',
            chart_resolution: '1_hour',
            chart_from: '1478080363',
            chart_to: '1477993963'
        },
        labels: ['PROVA1', 'PROVA2'],
        series: [
            {
                label: null,
                timestamp: 1478080363,
                values: [123, 345]
            },
            {
                label: null,
                timestamp: 1477993963,
                values: [153, 3435] 
            }
        ]
    };
    return $.ajax({
        url:'/rest/export/chart/xlsx',
        type: 'POST',
        dataType: 'application/json',
        contentType: 'application/json',
        data: JSON.stringify(urlParams)
    })
    .done(data => {
       console.log('success');
    })
    .fail(error => {
        console.log(error);
    });
};

The server receive the request and handle it correctly through this REST service:

@POST
@Path("xlsx")
@Produces("application/vnd.ms-excel")
public Response getXlsx(ChartExportRequest request) {
    ResponseBuilder responseBuilder;
    ChartExportRequestDTO reqDto = null;
    try {
        reqDto = parseDTO(request);
        checkRequestDTO(reqDto);
        ExportDTO dto = getXlsxProvider().create(reqDto);

        responseBuilder = Response.ok(dto.getFile())
                .header("Content-disposition", "attachment;filename=" + dto.getFileName());
    }
    catch(Exception e) {
        logger.error("Error providing export xlsx for tab RIGEDI with request [" + (reqDto != null ? reqDto.toString() : null) + "]", e);
        responseBuilder = Response.serverError().entity(e.getMessage());
    }
    return responseBuilder.build();
}

The problem is that the response arrives correctly to the client but then nothing happens: I am expecting that the browser shows the download dialog (example: in chrome I expect the bottom bar of downloads to appear with my file).

What am I doing wrong?

解决方案

AS per Nate's answer here, the response of Ajax request is not recognised by a browser as a file. It will behave in the same way for all Ajax responses. You need to trigger the download popup manually.

In my implementation, I used filesaverjs to trigger the download popup, once I have received the API response in reducer.

Since FileSaver uses blob for saving the file, I am sending the response from server as a blob, converting it into string array buffer and then using it to save my file. This approach was described in

Please find the sample code below for the reducer : (using reducer for state modification, as per Redux) reducer.js

let fileSaver = require("file-saver");


export default function projectReducer(state = {}, action)
{
    let project;
    switch (action.type) {
        case  GET_PROJECT_SUCCESS :
            project = Object.assign(action.response.data);
            return project;
        case EXPORT_AND_DOWNLOAD_DATA_SUCCESS :
            let data = s2ab(action.response.data);
            fileSaver.saveAs(new Blob([data], {type: "application/octet-stream"}), "test.xlsx");
            return state;


    }
    return state;

}

function s2ab(s) {
    var buf = new ArrayBuffer(s.length);
    var view = new Uint8Array(buf);
    for (var i = 0; i != s.length; ++i) {
        view[i] = s.charCodeAt(i) & 0xFF;
    }
    return buf;
}

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