src/helper/cell.js
/**
* Convert row label to index.
*
* @param {String} label Row label (eq. '1', '5')
* @returns {Number} Returns -1 if label is not recognized otherwise proper row index.
*/
export function rowLabelToIndex(label) {
let result = parseInt(label, 10);
if (isNaN(result)) {
result = -1;
} else {
result = Math.max(result - 1, -1);
}
return result;
}
/**
* Convert row index to label.
*
* @param {Number} row Row index.
* @returns {String} Returns row label (eq. '1', '7').
*/
export function rowIndexToLabel(row) {
let result = '';
if (row >= 0) {
result = `${row + 1}`;
}
return result;
}
const COLUMN_LABEL_BASE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
const COLUMN_LABEL_BASE_LENGTH = COLUMN_LABEL_BASE.length;
/**
* Convert column label to index.
*
* @param {String} label Column label (eq. 'ABB', 'CNQ')
* @returns {Number} Returns -1 if label is not recognized otherwise proper column index.
*/
export function columnLabelToIndex(label) {
let result = 0;
if (typeof label === 'string') {
label = label.toUpperCase();
for (let i = 0, j = label.length - 1; i < label.length; i += 1, j -= 1) {
result += Math.pow(COLUMN_LABEL_BASE_LENGTH, j) * (COLUMN_LABEL_BASE.indexOf(label[i]) + 1);
}
}
--result;
return result;
}
/**
* Convert column index to label.
*
* @param {Number} column Column index.
* @returns {String} Returns column label (eq. 'ABB', 'CNQ').
*/
export function columnIndexToLabel(column) {
let result = '';
while (column >= 0) {
result = String.fromCharCode((column % COLUMN_LABEL_BASE_LENGTH) + 97) + result;
column = Math.floor(column / COLUMN_LABEL_BASE_LENGTH) - 1;
}
return result.toUpperCase();
}
const LABEL_EXTRACT_REGEXP = /^([$])?([A-Za-z]+)([$])?([0-9]+)$/;
/**
* Extract cell coordinates.
*
* @param {String} label Cell coordinates (eq. 'A1', '$B6', '$N$98').
* @returns {Array} Returns an array of objects.
*/
export function extractLabel(label) {
if (typeof label !== 'string' || !LABEL_EXTRACT_REGEXP.test(label)) {
return [];
}
const [, columnAbs, column, rowAbs, row] = label.toUpperCase().match(LABEL_EXTRACT_REGEXP);
return [
{
index: rowLabelToIndex(row),
label: row,
isAbsolute: rowAbs === '$',
},
{
index: columnLabelToIndex(column),
label: column,
isAbsolute: columnAbs === '$',
},
];
}
/**
* Convert row and column indexes into cell label.
*
* @param {Object} row Object with `index` and `isAbsolute` properties.
* @param {Object} column Object with `index` and `isAbsolute` properties.
* @returns {String} Returns cell label.
*/
export function toLabel(row, column) {
const rowLabel = (row.isAbsolute ? '$' : '') + rowIndexToLabel(row.index);
const columnLabel = (column.isAbsolute ? '$' : '') + columnIndexToLabel(column.index);
return columnLabel + rowLabel;
}