javascript - 在 LWC 中解析大型 CSV 文件

Question

我已经实现了以下代码来解析 csv 文件、转换为 JSON 数组并将 JSON 结果发送到 apex 控制器，该控制器调用批处理类来处理 opportunityLineItem 对象的 DML 操作。该代码最多可以工作 4000 行（文件有 22 列的值）。当有 5000 条记录时，进程会抛出错误并停止（它不会调用 apex 服务器）。如果有 4000 条记录，为什么它会停止？解析 LWC 中的 csv 记录是否有任何限制？

代码：

if (!this.csvFile) {
      console.log("file not found");
      return;
    }
    this.showprogressbar = true;
    let reader = new FileReader();
    let ctx = this; // to control 'this' property in an event handler
    reader.readAsText(this.csvFile, "Shift_JIS");
    reader.onload = function (evt) {
      console.log('reader:'+evt.target.result);
      let payload = ctx.CSV2JSON(evt.target.result, ctx.CSVToArray);
      let json = null;
      let error = null;
      console.log("payload:" + payload);
      setJSON({
        payload: payload,
        crud: crud,
        csvFile:ctx.csvFile
      })
        .then((result) => {
          json = result;
          var err = json.includes("Error");
          console.log('err====='+err);
          if(err)
          {
            console.log('json==###=='+json);
              ctx.error = json;
              console.log("error:"+ctx.error);
              ///s/ alert('error');
              
              ctx.showloader=false;
              ctx.hasError=true;
          }
            else{
            ctx.jobinfo(json);
            console.log("apex call setJSON() ===> success: " + json);
            //ctx.error = undefined;
          }
        })
        .catch((error) => {
          error =ctx.error;
          console.log("error:" + error.errorCode + ', message ' + error.message);
          ///s/ alert('error');
          
          ctx.showloader=false;
          ctx.hasError=true;

   
          if (error && error.message) {
            json = "{'no':1,'status':'Error', 'msg':'" + error.message + "'}";
          } else {
            json = "{'no':1,'status':'Error','msg':'Unknown error'}";
          }
          
        });
    };
    reader.onerror = function (evt) {
      /*ctx.mycolumns = [
        { label: "no", fieldName: "no", type: "number", initialWidth: 50 },
        {
          label: "status",
          fieldName: "status",
          type: "text",
          initialWidth: 100
        },
        { label: "message", fieldName: "msg", type: "text" }
      ];
      ctx.mydata = [{ no: "1", status: "Error", msg: "error reading file" }];
            */
      //$A.util.toggleClass(spinner, "slds-hide"); // hide spinner
    };
        //  ctx.showloader=false;
    console.log("mydata:===" + ctx.mydata);
    alert('onerror');
    
  }
        
        

  CSV2JSON(csv, csv2array) {
    let array = csv2array(csv);
    //console.log("csv:::"+csv);
    //console.log("csv2array:"+csv2array);
    let objArray = [];
    //console.log("objArray:"+objArray);
    var headervar = oppheader;//'Name,BillingCity,Type,Industry';
    console.log('headervar:::'+headervar);
    let headerArray = headervar.split(',');
    for (let i = 1; i < array.length; i++) {
      objArray[i - 1] = {};
      /*for (let k = 0; k < array[0].length && k < array[i].length; k++) {
        let key = array[0][k];
        if(key === 'DW予定日')

        elseif(key === 'DW予定日')

        elseif(key === 'DW予定日')
        
        console.log("key:"+key);
        this.hearder=key;
        objArray[i - 1][key] = array[i][k];
      }*/
      for (let k = 0; k < headerArray.length; k++) {
        let key = headerArray[k];
        console.log("key====:"+key);
        this.hearder=key;
        objArray[i - 1][key] = array[i][k];
      }
    }
    objArray.pop();
    //console.log("objArray:==="+objArray.length);
    this.rowCount = objArray.length;
    //console.log("rowCount+++++++" + this.rowCount);
    let json = JSON.stringify(objArray);
    //console.log("json:==="+json.length);
    let str = json.replace("/},/g", "},\r\n");
    //console.log("str:======="+str);
    return str;
  }

  CSVToArray(strData, strDelimiter) {
    console.log('CSVToArray');
    // Check to see if the delimiter is defined. If not,
    // then default to comma.
    //console.log('strData:'+strData);
    //console.log("strDelimiter::" + strDelimiter);
    strDelimiter = strDelimiter || ",";
    //console.log("strDelimiter:" + strDelimiter);
    // Create a regular expression to parse the CSV values.
    var objPattern = new RegExp(
      // Delimiters.
      "(\\" +
        strDelimiter +
        "|\\r?\\n|\\r|^)" +
        // Quoted fields.
        '(?:"([^"]*(?:""[^"]*)*)"|' +
        // Standard fields.
        '([^"\\' +
        strDelimiter +
        "\\r\\n]*))",
      "gi"
    );
    // Create an array to hold our data. Give the array
    // a default empty first row.
   // console.log("objPattern:" + objPattern);
    var arrData = [[]];
    // Create an array to hold our individual pattern
    // matching groups.
   // console.log("arrData:" + arrData);
    var arrMatches = null;
    // Keep looping over the regular expression matches
    // until we can no longer find a match.
    while ((arrMatches = objPattern.exec(strData))) {
      // Get the delimiter that was found.
      var strMatchedDelimiter = arrMatches[1];
      // Check to see if the given delimiter has a length
      // (is not the start of string) and if it matches
      // field delimiter. If id does not, then we know
      // that this delimiter is a row delimiter.
      if (strMatchedDelimiter.length && strMatchedDelimiter != strDelimiter) {
        // Since we have reached a new row of data,
        // add an empty row to our data array.
        arrData.push([]);
      }
      // Now that we have our delimiter out of the way,
      // let's check to see which kind of value we
      // captured (quoted or unquoted).
      if (arrMatches[2]) {
        // We found a quoted value. When we capture
        // this value, unescape any double quotes.
        var strMatchedValue = arrMatches[2].replace(new RegExp('""', "g"), '"');
      } else {
        // We found a non-quoted value.
        var strMatchedValue = arrMatches[3];
      }
      // Now that we have our value string, let's add
      // it to the data array.
      arrData[arrData.length - 1].push(strMatchedValue);
    }
    // Return the parsed data.
    return arrData;
  }

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