html5的localStorage相信大家都是很熟悉了,但是在chrome等支持該對象的瀏覽器中(ie10除外),如果你監聽 storage變更事件你就會發現,當數據發生變化時本頁是監聽不到storage事件變更消息的。而同域的其他打開的頁面反而監聽到了該消息。悲劇不?
以上的機制應該是無可厚非的,但是對於單頁app或者數據驅動的頁面展現來說,這是一個讓人抓狂的規事情。awen在開發中為了實現一個純數據驅動的單頁app機制。不得不面對這個問題,經過測試終於實現了本頁面locaStorage變更監聽。
基本原理如下:
1 重新生成一個對象,包裝localStorage原生方法:
var Storage = { setItem : function(k,v){ localStorage.setItem(k,v); ...... }, removeItem : function(k){ localStorage.removeItem(k); ....... }, getItem : ... }
2 在能引起storage變更時間的操作接口中,手動觸發StorageEvent事件
比如removeItem的實現中,你就需要初始化並觸發StorageEvent事件:
var se = document.createEvent("StorageEvent"); se.initStorageEvent('storage', false, false, key, oldval, newval, url, storage); window.dispatchEvent(se);
3 通過自封裝的Storage對象操作,並在當前頁監聽:
window.addEventListener("storage",function(e){ console.log(e); },false); Storage.addItem('test','小朋友愛吃糖');
到此為止。StorageEvent的當前頁面監聽問題就解決了,爽不?
轉載:http://www.cnblogs.com/cczw/p/3196195.html
HTML5 localStorage and sessionStorage
HTML5 提供兩種web存儲方法,localStorage 與 sessionStorage
localStorage 與 sessionStorage 區別
localStorage沒有過期時間,只要不clear或remove,數據會一直保存。
sessionStorage 針對一個session進行數據存儲,生命周期與session相同,當用戶關閉瀏覽器后,數據將被刪除。
特點:
1.localStorage 默認支持的容量為一個站5M,當調用setItem超過上限時,會觸發QuotaExceededError異常。當然有些瀏覽器支持修改容量上限,但為了兼容其他瀏覽器,最好按5M的容量來使用。
2.localStorage 是以key-value形式保存數據的,key和value只能是字符串格式。因此數字1保存后,會轉換成字符串1。
3.localStorage 的寫入與讀取寫法有以下幾種:
localStorage.name = 'fdipzone'; name = localStorage.name; localStorage['name'] = 'fdipzone'; name = localStorage['name']; localStorage.setItem('name', 'fdipzone'); name = localStorage.getItem('name');
localStorage[key] = value寫法主流瀏覽器都支持,官方並沒有說明那一種寫法是標准。但如果執行以下的代碼就使localStorage失效。
localStorage.setItem = null; localStorage.getItem = null; localStorage.removeItem = null; localStorage.clear = null;
因此,建議使用setItem(), getItem(), removeItem(), clear()來實現寫入,讀取,刪除,清空。
4.如果要保存非字符串的內容,建議使用JSON來處理。寫入數據時用JSON.stringify轉成字符串,讀取數據時用JSON.parse把字符串轉為之前的格式。
例子1:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <title> Local Storage and Session Storage </title> </head> <body> <p>姓名:<input type="text" name="name" id="name"></p> <p>性別:<input type="radio" name="gender" id="gender1" value="1"> 男 <input type="radio" name="gender" id="gender2" value="2"> 女</p> <p><input type="button" id="saveBtn" value="save"> <input type="button" id="getBtn" value="get"> <input type="button" id="removeBtn" value="remove name"> <input type="button" id="clearBtn" value="clear"> </p> <script type="text/javascript"> var oStorage = window.localStorage; function $(id){ return document.getElementById(id); } // 保存數據 $('saveBtn').onclick = function(){ oStorage.setItem('name', $('name').value); if($('gender1').checked==true){ oStorage.setItem('gender', 1); }else if($('gender2').checked==true){ oStorage.setItem('gender', 2); } } // 獲取數據 $('getBtn').onclick = function(){ $('name').value = oStorage.getItem('name'); if(oStorage.getItem('gender')==1){ $('gender1').checked = true; }else if(oStorage.getItem('gender')==2){ $('gender2').checked = true; } } // 刪除數據name $('removeBtn').onclick = function(){ oStorage.removeItem('name'); } // 清空數據 $('clearBtn').onclick = function(){ oStorage.clear(); } </script> </body> </html>
例子2:使用 JSON.stringify 和 JSON.parse 封裝數據
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <title> Local Storage and Session Storage </title> </head> <body> <p>姓名:<input type="text" name="name" id="name"></p> <p>性別:<input type="radio" name="gender" id="gender1" value="1"> 男 <input type="radio" name="gender" id="gender2" value="2"> 女</p> <p><input type="button" id="saveBtn" value="save"> <input type="button" id="getBtn" value="get"> <input type="button" id="clearBtn" value="clear"> </p> <script type="text/javascript"> var oStorage = window.localStorage; function $(id){ return document.getElementById(id); } // 保存數據 $('saveBtn').onclick = function(){ var name = $('name').value; var gender; if($('gender1').checked==true){ gender = 1; }else if($('gender2').checked==true){ gender = 2; } var data = {}; data['name'] = name; data['gender'] = gender; oStorage.setItem('data', JSON.stringify(data)); } // 獲取數據 $('getBtn').onclick = function(){ var data = JSON.parse(oStorage.getItem('data')); if(data){ var name = data['name']; var gender = data['gender']; $('name').value = name; if(gender==1){ $('gender1').checked = true; }else if(gender==2){ $('gender2').checked = true; } } } // 清空數據 $('clearBtn').onclick = function(){ oStorage.clear(); } </script> </body> </html>
監聽localStorage的值,當發生變化時同步頁面數據
當調用setItem(), removeItem(), clear() 時,可以監聽這些事件,方便不同的頁面之間更新數據。
// 監聽數據變化,當數據發生變化時,同步數據顯示 window.onstorage = function(event){ var status = {} status.key = event.key; status.oldValue = event.oldValue; status.newValue = event.newValue; status.url = event.url; status.storage = event.storageArea; // 執行同步數據處理... }
頁面數據同步例子:
localStorage1.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <title> Local Storage and Session Storage </title> </head> <body> <p>姓名:<input type="text" name="name" id="name"></p> <p>性別:<input type="radio" name="gender" id="gender1" value="1"> 男 <input type="radio" name="gender" id="gender2" value="2"> 女</p> <p><input type="button" id="saveBtn" value="save"> <input type="button" id="getBtn" value="get"> <input type="button" id="clearBtn" value="clear"> </p> <script type="text/javascript"> var oStorage = window.localStorage; function $(id){ return document.getElementById(id); } // 保存數據 $('saveBtn').onclick = function(){ var name = $('name').value; var gender; if($('gender1').checked==true){ gender = 1; }else if($('gender2').checked==true){ gender = 2; } var data = {}; data['name'] = name; data['gender'] = gender; oStorage.setItem('data', JSON.stringify(data)); } // 獲取數據 $('getBtn').onclick = function(){ getStorageItem(); } // 獲取數據 function getStorageItem(){ var data = JSON.parse(oStorage.getItem('data')); var name,gender; if(data){ name = data['name']; gender = data['gender']; }else{ name = ''; gender = 0; } $('name').value = name; if(gender==1){ $('gender1').checked = true; }else if(gender==2){ $('gender2').checked = true; }else{ $('gender1').checked = false; $('gender2').checked = false; } } // 清空數據 $('clearBtn').onclick = function(){ oStorage.clear(); $('name').value = ''; $('gender1').checked = false; $('gender2').checked = false; } // 監聽數據變化,當數據發生變化時,同步數據顯示 window.onstorage = function(event){ var status = {} status.key = event.key; status.oldValue = event.oldValue; status.newValue = event.newValue; status.url = event.url; status.storage = event.storageArea; getStorageItem(); // 數據發生變化時,重新獲取數據 } </script> </body> </html>
localStorage2.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <title> Local Storage and Session Storage </title> </head> <body> <p>姓名:<input type="text" name="name" id="name"></p> <p>性別:<input type="radio" name="gender" id="gender1" value="1"> 男 <input type="radio" name="gender" id="gender2" value="2"> 女</p> <p><input type="button" id="saveBtn" value="save"> <input type="button" id="getBtn" value="get"> <input type="button" id="clearBtn" value="clear"> </p> <script type="text/javascript"> var oStorage = window.localStorage; function $(id){ return document.getElementById(id); } // 保存數據 $('saveBtn').onclick = function(){ var name = $('name').value; var gender; if($('gender1').checked==true){ gender = 1; }else if($('gender2').checked==true){ gender = 2; } var data = {}; data['name'] = name; data['gender'] = gender; oStorage.setItem('data', JSON.stringify(data)); } // 獲取數據 $('getBtn').onclick = function(){ getStorageItem(); } // 獲取數據 function getStorageItem(){ var data = JSON.parse(oStorage.getItem('data')); var name,gender; if(data){ name = data['name']; gender = data['gender']; }else{ name = ''; gender = 0; } $('name').value = name; if(gender==1){ $('gender1').checked = true; }else if(gender==2){ $('gender2').checked = true; }else{ $('gender1').checked = false; $('gender2').checked = false; } } // 清空數據 $('clearBtn').onclick = function(){ oStorage.clear(); $('name').value = ''; $('gender1').checked = false; $('gender2').checked = false; } // 監聽數據變化,當數據發生變化時,同步數據顯示 window.onstorage = function(event){ var status = {} status.key = event.key; status.oldValue = event.oldValue; status.newValue = event.newValue; status.url = event.url; status.storage = event.storageArea; getStorageItem(); // 數據發生變化時,重新獲取數據 } </script> </body> </html>
localstorage3.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <title> Local Storage and Session Storage </title> </head> <body> <p>姓名:<input type="text" name="name" id="name"></p> <p>性別:<input type="radio" name="gender" id="gender1" value="1"> 男 <input type="radio" name="gender" id="gender2" value="2"> 女</p> <p><input type="button" id="saveBtn" value="save"> <input type="button" id="getBtn" value="get"> <input type="button" id="clearBtn" value="clear"> </p> <script type="text/javascript"> var oStorage = window.localStorage; function $(id){ return document.getElementById(id); } // 保存數據 $('saveBtn').onclick = function(){ var name = $('name').value; var gender; if($('gender1').checked==true){ gender = 1; }else if($('gender2').checked==true){ gender = 2; } var data = {}; data['name'] = name; data['gender'] = gender; oStorage.setItem('data', JSON.stringify(data)); } // 獲取數據 $('getBtn').onclick = function(){ getStorageItem(); } // 獲取數據 function getStorageItem(){ var data = JSON.parse(oStorage.getItem('data')); var name,gender; if(data){ name = data['name']; gender = data['gender']; }else{ name = ''; gender = 0; } $('name').value = name; if(gender==1){ $('gender1').checked = true; }else if(gender==2){ $('gender2').checked = true; }else{ $('gender1').checked = false; $('gender2').checked = false; } } // 清空數據 $('clearBtn').onclick = function(){ oStorage.clear(); $('name').value = ''; $('gender1').checked = false; $('gender2').checked = false; } // 監聽數據變化,當數據發生變化時,同步數據顯示 window.onstorage = function(event){ var status = {} status.key = event.key; status.oldValue = event.oldValue; status.newValue = event.newValue; status.url = event.url; status.storage = event.storageArea; getStorageItem(); // 數據發生變化時,重新獲取數據 } </script> </body> </html>
轉載:http://blog.csdn.net/fdipzone/article/details/25517615
參考:http://www.smashingmagazine.com/2010/10/local-storage-and-how-to-use-it/
HTML5 Web Storage用法參考:
http://justcoding.iteye.com/blog/2092992
HTML5 本地存儲參考
http://www.cnblogs.com/rainman/archive/2011/06/22/2086069.html