Created
January 9, 2021 17:55
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| const express = require("express"); | |
| const { get } = require("axios").default; | |
| const { randomBytes } = require("crypto"); | |
| const app = express(); | |
| app.use(express.json()); | |
| const CSVtoJson = (csvStr = "", selected = []) => { | |
| var parsedRows = []; | |
| var quote = false; // inside quotes? | |
| for (var row = 0, col = 0, i = 0; i < csvStr.length; i++) { | |
| let currentChar = csvStr[i], | |
| nextChar = csvStr[i + 1]; | |
| parsedRows[row] = parsedRows[row] || []; // Create a new row if necessary | |
| parsedRows[row][col] = parsedRows[row][col] || ""; // Create a new column if necessary | |
| if (currentChar == '"' && quote && nextChar == '"') { | |
| parsedRows[row][col] += currentChar; | |
| ++i; | |
| continue; | |
| } | |
| if (currentChar == '"') { | |
| quote = !quote; | |
| continue; | |
| } | |
| if (currentChar == "," && !quote) { | |
| ++col; | |
| continue; | |
| } | |
| if (currentChar == "\r" && nextChar == "\n" && !quote) { | |
| ++row; | |
| col = 0; | |
| ++i; | |
| continue; | |
| } | |
| if ((currentChar == "\n" || currentChar == "\r") && !quote) { | |
| ++row; | |
| col = 0; | |
| continue; | |
| } | |
| parsedRows[row][col] += currentChar; | |
| } | |
| return tranformParsedArray(parsedRows, selected); | |
| }; | |
| const tranformParsedArray = (arr, selected) => { | |
| const result = []; | |
| const heads = trimArrItems(arr[0]); | |
| const errors = []; | |
| // validate csv | |
| arr.forEach(item => { | |
| if (item.length != arr[0].length) | |
| errors.push(genError("Not a valid CSV file")); | |
| }); | |
| if (errors.length > 0) return { errors }; | |
| const selectedHeadsIdx = selected.map(selectedItem => { | |
| const match = heads.findIndex( | |
| item => selectedItem.toLowerCase() == item.toLowerCase() | |
| ); | |
| if (match == -1) { | |
| errors.push({ [selectedItem]: "Not a valid column in csv" }); | |
| } else { | |
| return match; | |
| } | |
| }); | |
| arr.forEach((rowArr, rowIdx) => { | |
| let temp = {}; | |
| if (rowIdx == 0) return; | |
| trimArrItems(rowArr).forEach((item, itemIdx) => { | |
| if (selected.length < 1) { | |
| temp[heads[itemIdx]] = item; | |
| return; | |
| } | |
| if (selectedHeadsIdx.some(e => e === itemIdx)) { | |
| temp[heads[itemIdx]] = item; | |
| } | |
| }); | |
| result.push(temp); | |
| }); | |
| return { result, errors }; | |
| }; | |
| //helpers | |
| const trimArrItems = arr => { | |
| return arr.map(e => e.trim()); | |
| }; | |
| const genError = msg => ({ | |
| error: msg | |
| }); | |
| const fetchCSV = async url => (await get(url)).data; | |
| app.get("/", async (req, res) => { | |
| res.send("Please use a POST method instead"); | |
| }); | |
| app.post("/", async (req, res) => { | |
| const { select_fields, url } = req.body.csv || {}; | |
| if (!url) { | |
| res.json(genError("Please enter a url")); | |
| } | |
| let csv = ""; | |
| try { | |
| csv = await fetchCSV(url); | |
| } catch (err) { | |
| res.status(400).json(genError("url is probably invalid")); | |
| } | |
| const { errors, result } = CSVtoJson(csv, select_fields); | |
| if (errors && errors.length > 0) { | |
| res.status(400).json(genError(errors)); | |
| } else { | |
| res.json({ | |
| conversion_key: randomBytes(10).toString("hex"), | |
| json: result | |
| }); | |
| } | |
| }); | |
| const listener = app.listen(process.env.PORT, () => { | |
| console.log("Your app is listening on port " + listener.address().port); | |
| }); |
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