vue-scan-code/dist/index.js

a code scanning plug-in for vue

const eventSimple = require('event-simple');

var _Vue;

function Scan () {
  this.pointer = '';
  this.pointerQueue = [];
  this.code = '';
  this.nextCode = '';
  this.lastCode = '';
  this.name = 'scan';
  this.eventName = 'scancode';
  this.codeMinLength = 5;
  this.wait = 30;
  this.timer = null;
  this.handler = {};
  this.initScanCode = function (callback, vueExp) {
    if (typeof callback === 'function') {
      if ((vueExp._uid || vueExp._uid === 0) && !this.handler[this.name + vueExp._uid]) {
        var bool = this.pointerQueue.some(function (point) { return point == vueExp._uid });
        !bool && this.pointerQueue.push([vueExp._uid]);
        this.handler[this.name + vueExp._uid] = callback;
      } else if (this.handler[this.name + vueExp._uid]) {
        this.handler[this.name + vueExp._uid] = callback;
      } else {
        console.error('error: ~~~');
      }
    } else {
      console.error('the callback is only function');
    }
    this.pointer = vueExp._uid;
  };
  this.offScanCode = function (that) {
    if (that instanceof _Vue) {
      const pointerIndex = this.pointerQueue.findIndex(function (p) { return p == this._uid });
      if (pointerIndex > -1) {
        this.pointerQueue.splice(pointerIndex, -1);
        delete this.handler[this.name + this._uid];
      }
      this.pointer = '';
    } else {
      console.error('current Example not a vue example');
    }
  };
  this.bindScanCode = function (that, callback) {
    if (that instanceof _Vue) {
      if (typeof callback == 'function') {
        this.initScanCode(callback, that);
      }
    } else {
      console.error('current Example not a vue example');
    }
  };
  this.outputScanCode = function (code) {
    if (this.pointer && this.handler[this.name + this.pointer]) {
      this.handler[this.name + this.pointer](code);
    }
    this.clearCache();
  };
  this.getPrototypeName = function () {
    return '$' + this.name
  };
  this.clearCache = function () {
    this.nextCode = '';
    this.lastCode = '';
    this.code = '';
  };
}

Scan.prototype.init = function (options) {
  options && options.scanName && (this.name = options.scanName);
  options && options.scanWait && (this.wait = options.scanWait);
  options && options.scanCodeMinLength && (this.codeMinLength = options.scanCodeMinLength);
  var lastTime, nextTime, lastCode, nextCode;
  var self = this;
  window.addEventListener('keypress', function (e) {
    nextCode = e.which;
    nextTime = new Date().getTime();
    if (lastCode && lastTime && nextTime - lastTime <= self.wait) {
      if (lastCode) {
        self.lastCode += String.fromCharCode(lastCode);
      } else {
        self.lastCode += '';
      }
      if (nextCode) {
        self.nextCode += String.fromCharCode(nextCode);
      } else {
        self.nextCode += '';
      }
      eventSimple.emit(self.eventName, self.nextCode, self.lastCode);
    } else if (lastCode && lastTime && nextTime - lastTime > 100) {
      self.code = '';
    }
    lastCode = nextCode;
    lastTime = nextTime;
  });
  eventSimple.on(self.eventName, function (nextCode, lastCode) {
    clearTimeout(self.timer);
    self.timer = setTimeout(function () {
      if (nextCode.length >= self.codeMinLength && lastCode.length >= self.codeMinLength) {
        self.code = lastCode + nextCode.slice(lastCode.length - 1);
        self.outputScanCode(self.code);
      } else {
        console.error('current barcode length less than the options scanCodeMinLength');
        self.clearCache();
      }
    }, self.wait);
  });
};

var index = {
  install: function (Vue, options) {
    // eslint-disable-next-line no-undef
    if (_Vue === Vue) { return }
    _Vue = Vue;

    const sc = new Scan();
    window.scan = sc;
    sc.init(options || {});
    Vue.prototype[sc.getPrototypeName()] = sc;
  }
};

export default index;