riefive
82 lines
3.1 KiB
TypeScript
82 lines
3.1 KiB
TypeScript
/**
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* Download data as CSV file.
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*
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* @param headers - Array of header names. If omitted and data is array of objects, keys will be taken from first object.
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* @param data - Array of rows. Each row can be either an object (key -> value) or an array of values.
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* @param filename - optional file name to use for downloaded file
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* @param delimiter - csv delimiter (default is comma)
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* @param addBOM - add UTF-8 BOM to the file to make Excel detect UTF-8 correctly
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*/
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/*
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Usage examples:
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// 1) With headers and array of objects
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// downloadCsv(['name', 'age'], [{name: 'Alice', age: 25}, {name: 'Bob', age: 30}], 'people.csv');
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// 2) Without headers (automatically uses object keys)
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// downloadCsv(null, [{name: 'Alice', age: 25}, {name: 'Bob', age: 30}], 'people.csv');
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// 3) With array-of-arrays
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// downloadCsv(['col1', 'col2'], [['a', 'b'], ['c', 'd']], 'matrix.csv');
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*/
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export function downloadCsv(
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headers: string[] | null,
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data: Array<Record<string, any> | any[]>,
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filename = 'data.csv',
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delimiter = ',',
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addBOM = true,
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) {
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if (!Array.isArray(data) || data.length === 0) {
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// still create an empty CSV containing only headers
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const csvHeader = headers ? headers.join(delimiter) : ''
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const csvString = addBOM ? '\uFEFF' + csvHeader : csvHeader
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const blob = new Blob([csvString], { type: 'text/csv;charset=utf-8;' })
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const link = document.createElement('a')
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link.href = URL.createObjectURL(blob)
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link.setAttribute('download', filename)
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document.body.appendChild(link)
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link.click()
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document.body.removeChild(link)
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return
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}
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// if headers not provided and rows are objects, take keys from first object
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let _headers: string[] | null = headers
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if (!_headers) {
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const firstRow = data[0]
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if (typeof firstRow === 'object' && !Array.isArray(firstRow)) {
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_headers = Object.keys(firstRow)
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} else if (Array.isArray(firstRow)) {
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// if rows are arrays and no headers provided, we won't add header row
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_headers = null
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}
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}
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const escape = (val: unknown) => {
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if (val === null || typeof val === 'undefined') return ''
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const str = String(val)
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const needsQuoting = str.includes(delimiter) || str.includes('\n') || str.includes('\r') || str.includes('"')
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if (!needsQuoting) return str
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return '"' + str.replace(/"/g, '""') + '"'
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}
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const rows: string[] = data.map((row) => {
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if (Array.isArray(row)) {
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return row.map(escape).join(delimiter)
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}
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// object row - map using headers if available, otherwise use object values
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if (_headers && Array.isArray(_headers)) {
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return _headers.map((h) => escape((row as Record<string, any>)[h])).join(delimiter)
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}
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return Object.values(row).map(escape).join(delimiter)
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})
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const headerRow = _headers ? _headers.join(delimiter) : null
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const csvString = (addBOM ? '\uFEFF' : '') + [headerRow, ...rows].filter(Boolean).join('\r\n')
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const blob = new Blob([csvString], { type: 'text/csv;charset=utf-8;' })
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const link = document.createElement('a')
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link.href = URL.createObjectURL(blob)
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link.setAttribute('download', filename)
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document.body.appendChild(link)
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link.click()
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document.body.removeChild(link)
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}
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