我想从URL获取发布日期，可以使用以下代码获取它：window.dataLayer [0] ['publicationdate']，但是当需要使其在本地运行时，控制台会向我提供错误“无法读取未定义的属性'0'”。我有以下代码，有人可以帮我吗？谢谢！
"use strict";
var takashyx = takashyx || {};
takashyx.toast = (function() {
/**
* The main Toast object
* @param {Object} options See Toast.prototype.DEFAULT_SETTINGS for more info
*/
function Toast(text, options) {
if(getToastStage() != null) {
// If there is already a Toast being shown, hide it
Toast.prototype.destroy();
}
var _options = options || {};
_options = Toast.prototype.mergeOptions(Toast.prototype.DEFAULT_SETTINGS, _options);
Toast.prototype.show(text, _options);
_options = null;
};
/**
* The toastStage. This is the HTML element in which the toast resides
* Getter and setter methods are available privately
* @type {Element}
*/
var _toastStage = null;
function getToastStage() {
return _toastStage;
};
function setToastStage(toastStage) {
_toastStage = toastStage;
};
/**
* The Toast animation speed; how long the Toast takes to move to and from the screen
* @type {Number}
*/
Toast.prototype.TOAST_ANIMATION_SPEED = 400;
// Toast classes
Toast.prototype.CLASS_TOAST_GONE = "takashyx_toast_gone";
Toast.prototype.CLASS_TOAST_VISIBLE = "takashyx_toast_visible";
Toast.prototype.CLASS_TOAST_ANIMATED = "takashyx_toast_animated";
/**
* The default Toast settings
* @type {Object}
*/
Toast.prototype.DEFAULT_SETTINGS = {
style: {
main: {
"background": "rgba(0, 0, 0, .85)",
"box-shadow": "0 0 10px rgba(0, 0, 0, .8)",
"border-radius": "3px",
"z-index": "99999",
"color": "#01ff00",
"padding": "10px 15px",
"max-width": "40%",
"word-break": "keep-all",
"margin": "0 auto",
"text-align": "center",
"position": "fixed",
"left": "0",
"right": "0"
}
},
settings: {
duration: 4000
}
};
/**
* Specifies whether or not the inline style in the <head> exists. It only needs to be added once to a page
* @type {Boolean}
*/
Toast.prototype.styleExists = false;
/**
* The Timeout object for animations.
* This should be shared among the Toasts, because timeouts may be cancelled e.g. on explicit call of hide()
* @type {Object}
*/
Toast.prototype.timeout = null;
/**
* Merge the DEFAULT_SETTINGS with the user defined options if specified
* @param {Object} options The user defined options
*/
Toast.prototype.mergeOptions = function(initialOptions, customOptions) {
var merged = customOptions;
for(var prop in initialOptions) {
if(merged.hasOwnProperty(prop)) {
if(initialOptions[prop] != null && initialOptions[prop].constructor == Object) {
merged[prop] = Toast.prototype.mergeOptions(initialOptions[prop], merged[prop]);
}
} else {
merged[prop] = initialOptions[prop];
}
}
return merged;
};
/**
* Add the inline stylesheet to the <head>
* These inline styles are needed for animation purposes.
*/
Toast.prototype.initializeStyles = function() {
if(Toast.prototype.styleExists) return;
var style = document.createElement("style");
style.insertAdjacentHTML("beforeend",
Toast.prototype.generateInlineStylesheetRules(this.CLASS_TOAST_GONE, {
"opacity": "0",
"top": "10%"
}) +
Toast.prototype.generateInlineStylesheetRules(this.CLASS_TOAST_VISIBLE, {
"opacity": "1",
"top": "10%"
}) +
Toast.prototype.generateInlineStylesheetRules(this.CLASS_TOAST_ANIMATED, {
"transition": "opacity " + this.TOAST_ANIMATION_SPEED + "ms, bottom " + this.TOAST_ANIMATION_SPEED + "ms"
})
);
document.head.appendChild(style);
style = null;
// Notify that the stylesheet exists to avoid creating more
Toast.prototype.styleExists = true;
};
/**
* Generate the Toast with the specified text.
* @param {String|Object} text The text to show inside the Toast, can be an HTML element or plain text
* @param {Object} style The style to set for the Toast
*/
Toast.prototype.generate = function(text, style) {
var toastStage = document.createElement("div");
/**
* If the text is a String, create a textNode for appending
*/
if(typeof text === "string") {
var lines = text.split('[[[br]]]');
for (let i=0; i<lines.length; ++i) {
var l = document.createTextNode(lines[i]);
toastStage.appendChild(l);
var r = document.createElement('br');
toastStage.appendChild(r);
}
setToastStage(toastStage);
toastStage = null;
Toast.prototype.stylize(getToastStage(), style);
};
/**
* Stylize the Toast.
* @param {Element} element The HTML element to stylize
* @param {Object} styles An object containing the style to apply
* @return Returns nothing
*/
Toast.prototype.stylize = function(element, styles) {
Object.keys(styles).forEach(function(style) {
element.style[style] = styles[style];
console.log(style + ": "+ styles[style]);
});
};
/**
* Generates styles to be used in an inline stylesheet. The output will be something like:
* .class {background: blue;}
* @param {String} elementClass The class of the element to style
* @param {Object} styles The style to insert into the inline stylsheet
* @return {String} The inline style as a string
*/
Toast.prototype.generateInlineStylesheetRules = function(elementClass, styles) {
var out = "." + elementClass + "{";
Object.keys(styles).forEach(function(style) {
out += style + ":" + styles[style] + ";";
});
out += "}";
return out;
};
/**
* Show the Toast
* @param {String} text The text to show inside the Toast
* @param {Object} options The object containing the options for the Toast
*/
Toast.prototype.show = function(text, options) {
this.initializeStyles();
this.generate(text, options.style.main);
var toastStage = getToastStage();
toastStage.classList.add(this.CLASS_TOAST_ANIMATED);
toastStage.classList.add(this.CLASS_TOAST_GONE);
document.body.insertBefore(toastStage, document.body.firstChild);
// This is a hack to get animations started. Apparently without explicitly redrawing, it'll just attach the class and no animations would be done
toastStage.offsetHeight;
toastStage.classList.remove(this.CLASS_TOAST_GONE);
toastStage.classList.add(this.CLASS_TOAST_VISIBLE);
var toastStage = null;
clearTimeout(Toast.prototype.timeout);
Toast.prototype.timeout = setTimeout(Toast.prototype.hide, options.settings.duration);
};
/**
* Hide the Toast that's currently shown
*/
Toast.prototype.hide = function() {
var toastStage = getToastStage();
toastStage.classList.remove(Toast.prototype.CLASS_TOAST_VISIBLE);
toastStage.classList.add(Toast.prototype.CLASS_TOAST_GONE);
toastStage = null;
// Destroy the Toast element after animations end
clearTimeout(Toast.prototype.timeout);
Toast.prototype.timeout = setTimeout(Toast.prototype.destroy, Toast.prototype.TOAST_ANIMATION_SPEED);
};
/**
* Clean up after the Toast slides away. Namely, removing the Toast from the DOM.
*/
Toast.prototype.destroy = function() {
var toastStage = getToastStage();
document.body.removeChild(toastStage);
toastStage = null;
setToastStage(null);
};
return {
Toast: Toast
};
})();