75 lines
1.7 KiB
JavaScript
75 lines
1.7 KiB
JavaScript
const csv = require("csvtojson")
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const VALIDATORS = {
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string: () => true,
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number: attribute => !isNaN(Number(attribute)),
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datetime: attribute => !isNaN(new Date(attribute).getTime()),
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}
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const PARSERS = {
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number: attribute => Number(attribute),
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datetime: attribute => new Date(attribute).toISOString(),
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}
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function parse(csvString, parsers) {
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const result = csv().fromString(csvString)
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const schema = {}
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return new Promise((resolve, reject) => {
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result.on("header", headers => {
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for (let header of headers) {
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schema[header] = {
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type: parsers[header] ? parsers[header].type : "string",
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success: true,
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}
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}
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})
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result.subscribe(row => {
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// For each CSV row parse all the columns that need parsed
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for (let key in parsers) {
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if (!schema[key] || schema[key].success) {
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// get the validator for the column type
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const validator = VALIDATORS[parsers[key].type]
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try {
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// allow null/undefined values
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schema[key].success = !row[key] || validator(row[key])
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} catch (err) {
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schema[key].success = false
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}
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}
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}
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})
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result.on("done", error => {
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if (error) {
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console.error(error)
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reject(error)
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}
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resolve(schema)
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})
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})
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}
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async function transform({ schema, csvString }) {
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const colParser = {}
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for (let key in schema) {
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colParser[key] = PARSERS[schema[key].type] || schema[key].type
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}
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try {
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const json = await csv({ colParser }).fromString(csvString)
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return json
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} catch (err) {
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console.error(`Error transforming CSV to JSON for data import`, err)
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throw err
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}
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}
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module.exports = {
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parse,
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transform,
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}
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