javascript - 使用 JavaScript 将 JSON 文件转换为 CSV

Question

我正在尝试使用 JavaScript 将 JSON 文件转换为可以在 excel 中打开的 csv。

我有什么:

function exportToCsv(filename, rows) {
        var processRow = function (row) {
            var finalVal = '';
            for (var j = 0; j < row.length; j++) {
                var innerValue = row[j] === null ? '' : row[j].toString();
                if (row[j] instanceof Date) {
                    innerValue = row[j].toLocaleString();
                };
                var result = innerValue.replace(/"/g, '""');
                if (result.search(/("|,|\n)/g) >= 0)
                    result = '"' + result + '"';
                if (j > 0)
                    finalVal += ',';
                finalVal += result;
            }
            return finalVal + '\n';
        };

        var csvFile = '';
        for (var i = 0; i < rows.length; i++) {
            csvFile += processRow(rows[i]);
        }

        var blob = new Blob([csvFile], { type: 'text/csv;charset=utf-8;' });
        if (navigator.msSaveBlob) { // IE 10+
            navigator.msSaveBlob(blob, filename);
        } else {
            var link = document.createElement("a");
            if (link.download !== undefined) { // feature detection
                // Browsers that support HTML5 download attribute
                var url = URL.createObjectURL(blob);
                link.setAttribute("href", url);
                link.setAttribute("download", filename);
                link.style.visibility = 'hidden';
                document.body.appendChild(link);
                link.click();
                document.body.removeChild(link);
            }
        }
    }



exportToCsv('export.csv', 'FILENAME.JSON')

FILENAME.JSON(非常详细的嵌套示例)

[{
    "countyCode": 18,
    "excludedFlag": null,
    "fees": {
      "annualTotalFees": 35.6,
      "annualTotalFeesMail": 36.35,
      "annualTotalFeesOnline": 38.35,
      "biennialTotalFees": 71.2,
      "biennialTotalFeesMail": 71.95,
      "biennialTotalFeesOnline": 73.95,
      "branchFeeFlag": false,
      "delinquentFeeAmount": 5,
      "mhBackTax": 0,
      "mhBackTaxMonths": 0
    },
    "fileId": 876,
    "id": "2398743-32403274-2398",
    "messages": [
      {
        "messageCode": "RN2",
        "messageText": "Plate must be replaced if a 2 year renewal is desired.",
        "messageType": "I"
      },
      {
        "messageCode": "RN40",
        "messageText": "You must complete the affidavit on the reverse side or provide a copy of your Florida insurance identification card.",
        "messageType": "I"
      },
      {
        "messageCode": "RN41",
        "messageText": "Insurance is on file.",
        "messageType": "II"
      }
    ],
    "registrationDetail": {
      "annualPlateReplacementFlag": false,
      "arfCredit": 25.6,
      "biennialPlateReplacementFlag": true,
      "customerStopFlag": null,
      "delinquentDate": "2018-02-11T00:00:00",
      "expirationDate": "2018-01-09T00:00:00",
      "foreignAddressFlag": false,
      "honorayConsulPlateFlag": null,
      "hovDecalNumber": null,
      "hovDecalYear": null,
      "hovExpirationDate": null,
      "inventorySubtype": "RP",
      "lastActivityCounty": 15,
      "legislativePlateDueForReplacementFlag": false,
      "licensePlateCode": "RPR",
      "licensePlateNumber": "Plate",
      "mailToAddressFlag": false,
      "mailToCustomerNumber": null,
      "mhLocationCode": null,
      "militaryOwnerFlag": false,
      "numberOfRegistrants": 1,
      "onlineRenewalEligibilityFlag": true,
      "pinNumber": 329874938,
      "plateExpirationDate": "2018-03-18T00:00:00",
      "plateIssueDate": "2008-09-18T00:00:00",
      "possibleNgExemptionFlag": false,
      "registrationNumber": 3945874398,
      "registrationOnlyFlag": null,
      "registrationType": "R",
      "registrationUse": "PR",
      "renewalCountyCode": 16,
      "rentalParkFlag": null,
      "seminoleMiccosukeeIndianFlag": false,
      "taxCollectorRenewalEligibilityFlag": true,
      "vehicleClassCode": 1
    },
    "registrationOwners": [
      {
        "customer": {
          "addresses": [
            {
              "addressType": "R",
              "city": "BRADENTON",
              "countryCode": "US",
              "countyCode": 16,
              "foreignPostalCode": null,
              "state": "FL",
              "streetAddress": "24545 6th ave w",
              "zipCode": 34205,
              "zipPlus": null
            },
            {
              "addressType": "M",
              "city": "BRADENTON",
              "countryCode": "US",
              "countyCode": 16,
              "foreignPostalCode": null,
              "state": "FL",
              "streetAddress": "24545 6th ave w",
              "zipCode": 34205,
              "zipPlus": 8344
            }
          ],
          "companyName": null,
          "customerNumber": 3490436,
          "customerStopFlag": false,
          "customerType": "I",
          "dateOfBirth": "1971-01-09T00:00:00",
          "dlExpirationDate": "2025-01-09T00:00:00",
          "dlRenewalEligibilityFlag": true,
          "driverLicenseNumber": "N0932433902",
          "emailAddress": null,
          "feidNumber": null,
          "firstName": "Test",
          "lastName": "Name",
          "middleName": "Name",
          "militaryExemptionFlag": false,
          "nameSuffix": null,
          "sex": "F"
        },
        "registrationOwnershipNumber": 1
      }
    ],
    "shippingAddress": {
      "address": {
        "addressType": "S",
        "city": "BRADENTON",
        "countryCode": "US",
        "countyCode": 15,
        "foreignPostalCode": null,
        "state": "FL",
        "streetAddress": "24545 6th ave w",
        "zipCode": 34205,
        "zipPlus": 8344
      },
      "shippingCompanyName": null,
      "shippingName1": "Test Name",
      "shippingName2": null
    },
    "stops": null,
    "vehicle": {
      "address": null,
      "bodyCode": "4D",
      "brakeHorsePower": null,
      "cubicCentimeters": null,
      "grossWeight": null,
      "insuranceAffidavitCode": null,
      "leaseOwnerFlag": false,
      "lengthFeet": null,
      "lengthInches": null,
      "majorColorCode": "GLD",
      "makeCode": "CHEV",
      "minorColorCode": null,
      "netWeight": 3200,
      "numberOfAxles": null,
      "ownerUnitNumber": null,
      "titleNumber": 32434324,
      "vehicleIdentificationNumber": "1F5ZD5EU5BF32434234",
      "vehicleNumber": 324334,
      "vehicleType": "AU",
      "vesselCode": null,
      "vesselManufacturerDesc": null,
      "vesselResidentStatus": "Y",
      "vesselWaterType": null,
      "widthFeet": null,
      "widthInches": null,
      "yearMake": 2011
    }
  }
]

我正在尝试弄清楚如何将 json 文件放到底部显示 FILENAME.JSON 的地方。

我的最终目标是允许用户选择一个文件以将“大”json 文件转换为 csv 文件。每个月都会有一个新的 json 文件，所以我试图让用户轻松选择要转换的文件。有没有一种简单的方法可以绑定(bind)此 JavaScript 以允许用户选择文件？

如有任何帮助，我们将不胜感激。

编辑(我在下面尝试的方法还没有奏效。它像在做某事一样旋转，但从不下载或创建文件。)

    <!DOCTYPE html>
    <html lang="en">
    <head>

        <meta charset="utf-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">

        <title>json2csv</title>

        <meta id="viewport" name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
        <meta name="apple-mobile-web-app-capable" content="yes">
      <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js" crossorigin="anonymous"></script>
    </head>
    <body>


            <div id="content"></div>

        </body>
            <script type="text/javascript">
            fetch('http://path/to/json/file')
           .then(function(response) {
         function flatObjectToString(obj){
             var s = ""
             Object.keys(obj).map(key=>{
                 if(obj[key] === null){
                         s+= key +":"
                 }else if(obj[key].toLocaleDateString){
                     s+=key+": " +obj[key].toLocaleDateString() +"\n"
                 }else if(obj[key] instanceof Array){
                     s+= key+":\n" +listToFlatString(obj[key])
                 }else if(typeof obj[key] ==  "object"){
                     s+= key+":\n" +flatObjectToString(obj[key])
                 }else{
                     s+= key+":" +obj[key]
                 }
                 s+= "\n"
             })
             return s
         }

         function listToFlatString(list) {
                 var s = "";
                 list.map(item => {
                         Object.keys(item).map(key => {
                                 s+="\n"
                                 if (item[key] instanceof Array) {
                                         s += key + "\n" + listToFlatString(item[key])
                                 }else if(typeof item[key] == "object" && item[key] !== null){
                                        s+= key+": " + flatObjectToString(item[key])

                                 } else {
                                         s += key + ": " + (item[key] === null ? "" : item[key].toLocaleDateString ? item[key].toLocaleDateString : item[key].toString())
                                 }
                         })
                 })
                 return s;
         }

         function flatten(object, addToList, prefix) {
                 Object.keys(object).map(key => {
                         if (object[key] === null) {
                                 addToList[prefix + key] = ""
                         } else
                                 if (object[key] instanceof Array) {
                                     addToList[prefix + key] =   listToFlatString(object[key])
                                 } else if (typeof object[key] == 'object' && !object[key].toLocaleDateString) {
                                            flatten(object[key], addToList, prefix + key + '.')
                                 }else{
                                     addToList[prefix + key] = object[key]
                                 }
                 })
                 return addToList
         }

         exportToCsv("download.csv", data.map(record=>flatten(record, {}, '')))
  })
        </script>
        </html>

Answer 1

如果您只想删除一个 JSON 文件，您有几个选择:

1. 您可以粘贴 JSON 结构。

   JSON.parse(`{"name":"Sample","Age":1}`);
   

2. 可以使用fetch加载文件

   fetch('http://example.com/mylist.json')
     .then(function(response) {
       return exportToCsv("myfilename", response.json());
     })
   

   您可以使用它来展平列表:

   function flatObjectToString(obj){
   var s = ""
   Object.keys(obj).map(key=>{
     if(obj[key] === null){
         s+= key +":"
     }else if(obj[key].toLocaleDateString){
       s+=key+": " +obj[key].toLocaleDateString() +"\n"
     }else if(obj[key] instanceof Array){
       s+= key+":\n" +listToFlatString(obj[key])
     }else if(typeof obj[key] ==  "object"){
       s+= key+":\n" +flatObjectToString(obj[key])
     }else{
       s+= key+":" +obj[key]
     }
     s+= "\n"
   })
   return s
   }
   
   function listToFlatString(list) {
     var s = "";
     list.map(item => {
         Object.keys(item).map(key => {
             s+="\n"
             if (item[key] instanceof Array) {
                 s += key + "\n" + listToFlatString(item[key])
             }else if(typeof item[key] == "object" && item[key] !== null){
                s+= key+": " + flatObjectToString(item[key])
   
             } else {
                 s += key + ": " + (item[key] === null ? "" : item[key].toLocaleDateString ? item[key].toLocaleDateString : item[key].toString())
             }
         })
     })
     return s;
   }
   
   function flatten(object, addToList, prefix) {
     Object.keys(object).map(key => {
         if (object[key] === null) {
             addToList[prefix + key] = ""
         } else
             if (object[key] instanceof Array) {
               addToList[prefix + key] =   listToFlatString(object[key])
             } else if (typeof object[key] == 'object' && !object[key].toLocaleDateString) {
                  flatten(object[key], addToList, prefix + key + '.')
             }else{
               addToList[prefix + key] = object[key]
             }
     })
     return addToList
   }
   
   exportToCsv("download.csv", data.map(record=>flatten(record, {}, '')))