sheetjs/modules/src/prebnccell.ts

41 lines
1.6 KiB
TypeScript

/*! sheetjs (C) 2013-present SheetJS -- http://sheetjs.com */
import { CellObject } from '../../';
import { u8_to_dataview, popcnt } from './util';
function parseit(buf: Uint8Array, version: number): CellObject {
var dv = u8_to_dataview(buf);
var ctype = buf[version == 4 ? 1 : 2];
/* TODO: find the correct field position of number formats, formulae, etc */
var flags = dv.getUint32(4, true);
var data_offset = 12 + popcnt(flags & 0x3F8E) * 4;
var sidx = -1, ieee = NaN, dt = NaN;
if(flags & 0x10) { sidx = dv.getUint32(data_offset, true); data_offset += 4; }
if(flags & 0x20) { ieee = dv.getFloat64(data_offset, true); data_offset += 8; }
if(flags & 0x40) { dt = dv.getFloat64(data_offset, true); data_offset += 8; }
var ret;
switch(ctype) {
case 0: break; // return { t: "z" }; // blank?
case 2: ret = { t: "n", v: ieee }; break;
case 3: ret = { t: "s", v: sidx }; break;
case 5: var dd = new Date(2001, 0, 1); dd.setTime(dd.getTime() + dt * 1000); ret = { t: "d", v: dd }; break; // date-time TODO: relative or absolute?
case 6: ret = { t: "b", v: ieee > 0 }; break;
case 7: ret = { t: "n", v: ieee }; break; // duration in seconds TODO: emit [hh]:[mm] style format with adjusted value
default: throw new Error(`Unsupported cell type ${buf.slice(0,4)}`);
}
/* TODO: Some fields appear after the cell data */
return ret;
}
function parse(buf: Uint8Array): CellObject {
var version = buf[0]; // numbers 3.5 uses "3", 6.x - 11.x use "4"
switch(version) {
case 3: case 4: return parseit(buf, version);
default: throw new Error(`Unsupported pre-BNC version ${version}`);
}
}
export { parse };