json - 如何将 json 对象转换为 .csv 文件以及如何使用 Ionic 2 + angular 2 导出？

Question

我在 angular 2 应用程序中使用一个函数将 JSON 数据转换并导出为 .CSV。以下是我的功能，在 angular 2 应用程序中运行良好
(网络)。与我尝试在使用 Ionic 2 开发的移动应用程序中使用的相同，它在移动应用程序中不起作用。有没有办法做到这一点？

谢谢!

saveAsCSV() {
       let sampleJson : any = [{name:'ganesh', age:'24'},{name:'ramesh', age:'24'},{name:'suresh', age:'24'}]
       this.saveData = [];    
       let a = document.createElement("a");    
        a.setAttribute('style', 'display:none;');    
        document.body.appendChild(a);    
       let csvData = ConvertToCSV(sampleJson);    
       let blob = new Blob([csvData], { type: 'text/csv' });    
       let url= window.URL.createObjectURL(blob);    
        a.href = url;    
        a.download = 'sample.csv'; 
        a.click();    
  }

ConvertToCSV(objArray) {    
        let array = typeof objArray != 'object' ? JSON.parse(objArray) : objArray;
        let str = '';
        let row = ""; 
        for (let index in objArray[0]) {
            //Now convert each value to string and comma-separated
            row += index + ',';
        }
        row = row.slice(0, -1);
        //append Label row with line break
        str += row + '\r\n';

        for (let i = 0; i < array.length; i++) {
            let line = '';
            for (let index in array[i]) {
                if (line != '') line += ',';
                line += array[i][index];
            }
            str += line + '\r\n';
        }
        return str;
    }

Answer 1

使用“cordova-plugin-file”在 Ionic 2 中导出 csv。

https://cordova.apache.org/docs/en/latest/reference/cordova-plugin-file/

如果您看到以下错误 -

代码:1 消息:“NOT_FOUND_ERR”

在 config.xml 中添加以下行之一来解决它。

<preference name="AndroidPersistentFileLocation" value="Internal" />
<preference name="AndroidPersistentFileLocation" value="Compatibility" />

如插件文档中所述，您可以使用这两个选项之一:

choose whether to store files in the internal file storage location, or using the previous logic, with a preference in your application's config.xml file. Without this line, the File plugin will use Internal as the default. If a preference tag is present, and is not one of these values, the application will not start.

If your application has previously been shipped to users, using an older (pre- 3.0.0) version of this plugin, and has stored files in the persistent filesystem, then you should set the preference to Compatibility if your config.xml does not specify a location for the persistent filesystem. Switching the location to "Internal" would mean that existing users who upgrade their application may be unable to access their previously-stored files, depending on their device.

If your application is new, or has never previously stored files in the persistent filesystem, then the Internal setting is generally recommended.