我有这段代码,它正在使用localStorage html5调用。然而,它必须为Chrome桌面应用程序重写,我不知道如何将其移植过来。
window.fakeStorage = {
_data: {},
setItem: function (id, val) {
return this._data[id] = String(val);
},
getItem: function (id) {
return this._data.hasOwnProperty(id) ? this._data[id] : undefined;
},
removeItem: function (id) {
return delete this._data[id];
},
clear: function () {
return this._data = {};
}
};
function LocalScoreManager() {
this.key = "bestScore";
var supported = this.localStorageSupported();
this.storage = supported ? window.localStorage : window.fakeStorage;
}
LocalScoreManager.prototype.localStorageSupported = function () {
var testKey = "test";
var storage = window.localStorage;
try {
storage.setItem(testKey, "1");
storage.removeItem(testKey);
return true;
} catch (error) {
return false;
}
};
LocalScoreManager.prototype.get = function () {
return this.storage.getItem(this.key) || 0;
};
LocalScoreManager.prototype.set = function (score) {
this.storage.setItem(this.key, score);
};
我得到的错误是"window.localStorage在打包的应用程序中不可用。请使用chrome.storage.local。">
到目前为止,我重写它的尝试是这样的。。但它在途中的某个地方断裂了。
$(document).ready(function() {
$("body").bind('keyup', function() {
var number = $(".best-container").val();
if(number == 'undefined'){
var number = "0";
}
chrome.storage.local.set({'bestScore': number});
});
chrome.storage.local.get('bestScore', function (result) {
hello= result.bestScore || 0;
$(".best-container").val(hello);
});
});
将localStorage移植到chrome.storage有一个重要的陷阱:chrome.store方法是异步的,而localStorage访问是同步的。
这意味着:如果你试图在调用set
方法的回调之前从chrome.storage中获取一个值,那么这个值仍然是未定义的
错误的方式:
chrome.storage.local.set({'key': value});
...
chrome.storage.local.get('key', function(items) {
if(items.key) // won't be able to find the key
alert(items.key);
});
正确方式:
chrome.storage.local.set({'key': value}, function() {
...
chrome.storage.local.get('key', function(items) {
if(items.key)
alert(items.key); // will be "value"
});
});
或者更确切地说:
chrome.storage.local.set({'key': value}, function() {
doFurtherStuff();
});
function doFurtherStuff() {
...
chrome.storage.local.get('key', function(items) {
if(items.key)
alert(items.key); // will be "value"
});
}