@cheprasov/qrcode/src/QRCodeRaw.js

The library is for generating QR codes like SVG, HTML5 Canvas, PNG and JPG files, or text.

// @flow
/*
 * This file is part of QR code library
 * git: https://github.com/cheprasov/js-qrcode
 *
 * (C) Alexander Cheprasov <acheprasov84@gmail.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

import QRCodeCore from 'qr.js/lib/QRCode';
import ErrorCorrectLevel from 'qr.js/lib/ErrorCorrectLevel';

export const ERROR_CORRECTION_LEVEL_LOW = 'L'; // Allows recovery of up to 7% data loss
export const ERROR_CORRECTION_LEVEL_MEDIUM = 'M'; // Allows recovery of up to 15% data loss
export const ERROR_CORRECTION_LEVEL_QUARTILE = 'Q'; // Allows recovery of up to 25% data loss
export const ERROR_CORRECTION_LEVEL_HIGH = 'H'; // Allows recovery of up to 30% data loss

export type ErrorCorrectionLevelType = ERROR_CORRECTION_LEVEL_LOW | ERROR_CORRECTION_LEVEL_MEDIUM
    | ERROR_CORRECTION_LEVEL_QUARTILE | ERROR_CORRECTION_LEVEL_HIGH;

export type OptionsType = {
    level: ErrorCorrectionLevelType,
    typeNumber: number,
    padding: number,
    invert: boolean,
    errorsEnabled: boolean,
};

export type QRCodeDataType = boolean[][];

const DEFAULT_CONSTRUCTOR_PARAMS: OptionsType = {
    level: ERROR_CORRECTION_LEVEL_LOW,
    padding: 1,
    invert: false,
    typeNumber: 0,
    errorsEnabled: false,
};

export default class QRCodeRaw {

    value: string;
    level: ErrorCorrectionLevelType;
    typeNumber: number;
    padding: number;
    errorsEnabled: boolean;

    qrCodeData: ?QRCodeDataType;

    constructor(value: string, options: OptionsType = {}) {
        const params = { ...DEFAULT_CONSTRUCTOR_PARAMS, ...options };

        this.value = value;
        this.level = params.level;
        this.typeNumber = params.typeNumber;
        this.padding = params.padding;
        this.invert = params.invert;
        this.errorsEnabled = params.errorsEnabled;
    }

    setValue(value: string): void {
        this.value = value;
        this._clearCache();
    }

    getDataSize(): number {
        const data = this.getData();
        return data ? data.length : 0;
    }

    _clearCache(): void {
        this.qrCodeData = null;
    }

    _getQrCodeData(modules: QRCodeDataType): QRCodeDataType {
        const qrCodeData = [];

        const padding = this.padding;
        const invert = this.invert;
        const rowPadding = Array(padding * 2 + modules.length).fill(invert);
        const rowsPadding = Array(padding).fill(rowPadding);
        const columnPadding = Array(padding).fill(invert);

        if (padding) {
            qrCodeData.push(...rowsPadding);
        }
        modules.forEach((row: boolean[]) => {
            const qrCodeRow = [];
            qrCodeRow.push(
                ...columnPadding,
                ...(row.map(isBlack => (invert ? !isBlack : isBlack))),
                ...columnPadding,
            );
            qrCodeData.push(qrCodeRow);
        });
        if (padding) {
            qrCodeData.push(...rowsPadding);
        }

        return qrCodeData;
    }

    getData(): ?QRCodeDataType {
        if (!this.qrCodeData) {
            try {
                const qrcode = new QRCodeCore(this.typeNumber, ErrorCorrectLevel[this.level]);
                qrcode.addData(this.value);
                qrcode.make();
                if (!qrcode.modules) {
                    return null;
                }
                this.qrCodeData = this._getQrCodeData(qrcode.modules);
                Object.freeze(this.qrCodeData);
            } catch (error) {
                if (this.errorsEnabled) {
                    throw error;
                }
                return null;
            }
        }
        return this.qrCodeData;
    }

}