calpine-node/examples/excel2json/excel2json.js

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const XLSX = require("xlsx");
const fs = require("fs");
// do export for excel to json output or data json object
function _internalExport() {
const NAME = process.env.APP_NAME || "excel2json";
console.log("APP NAME =>", NAME, "\n");
// load from env
const INPUT_FILE = process.env.INPUT_FILE || "./data/people.xlsx";
const OUTPUT_PATH = process.env.OUTPUT_PATH || "./data/outputs";
const MAPPER_FILE = process.env.MAPPER_FILE || "./data/mapper.json";
const SHEET_NAME = process.env.SHEET_NAME || "Sheet1";
const ENCODING = process.env.ENCODING || "utf-8";
// get mapper in string
var mapperString = undefined;
try {
mapperString = fs.readFileSync(
MAPPER_FILE,
{ encoding: ENCODING },
(err) => {
if (err) {
console.error(err);
}
console.log("Load file suceed =>", MAPPER_FILE);
}
);
} catch (err) {
console.error("read file error", err);
}
// convert mapper from string to json object
const mapperJson = mapperString ? JSON.parse(mapperString) : {};
const configs = mapperJson.configs || {};
const columsData = mapperJson.data || undefined;
// read workbook from excel file
const wb = XLSX.readFile(configs.inputFile || INPUT_FILE);
const xlData = XLSX.utils.sheet_to_json(
wb.Sheets[configs.sheetName || SHEET_NAME]
);
// mapping the data from read excel file
const data = xlData.map((row) => {
if (columsData == undefined || !columsData) {
return row;
}
var _r = {};
columsData.map((col) => {
_r[col.label] = row[col.dataIndex];
});
return _r;
});
// parse a new path
const outputPath = configs.outputPath || OUTPUT_PATH;
// check directory and create it if not exist
if (!fs.existsSync(outputPath)) {
fs.mkdirSync(outputPath, { recursive: true });
}
// able to save to output or not (default is true)
const saveToOutput = configs.saveToOutput || true;
if (saveToOutput) {
// json data output
const jsonStringData = JSON.stringify(data);
try {
// write to file
fs.writeFileSync(
`${outputPath}/${
configs.outputName || "exported"
}_${new Date().getTime()}.json`,
jsonStringData,
(err) => {
if (err) throw err;
console.log("Write succeed!");
}
);
} catch (err) {}
}
return data;
}
/**
* excel2json
* Allow to export data from excel to json object or output of json.
*
* @returns JSON Object of result
*/
module.exports = excel2json = () => {
return _internalExport()
}