HTML5 storage提供了一種方式讓網站能夠把信息存儲到你本地的計算機上，并再以后需要的時候進行獲取。這個概念和cookie相似，區別是它是為了更大容量存儲設計的。Cookie的大小是受限的，并且每次你請求一個新的頁面的時候cookie都會被發送過去。HTML5的storage是存儲在你的計算機上，網站在頁面加載完畢后可以通過Javascript來獲取這些數據。首先自然是檢測瀏覽器是否支持本地存儲。在HTML5中，本地存儲是一個window的屬性，包括localStorage和sessionStorage，從名字應該可以很清楚的辨認二者的區別，前者是一直存在本地的，后者只是伴隨著session，窗口一旦關閉就沒了。二者用法完全相同，這里以localStorage為例。
存儲數據的方法就是直接給window.localStorage添加一個屬性，例如：window.localStorage.a 或者 window.localStorage["a"]。它的讀取、寫、刪除操作方法很簡單，是以鍵值對的方式存在的，如下：
這里最推薦使用的自然是getItem()和setItem()，清除鍵值對使用removeItem()。如果希望一次性清除所有的鍵值對，可以使用clear()。另外，HTML5還提供了一個key()方法，可以在不知道有哪些鍵值的時候使用，如下：
表單實時保存數據，下次打開則提示是否繼續編輯。圖片等控件不支持，只支持簡單的控件。【防止突然斷電或瀏覽器崩潰時，下次打開還可以繼續編輯并保存】。這樣自然而然就想到了HTML5的本地存儲功能。既然js寫的爛，寫的差，就當練手了。
/**
* 功能：保存用戶修改完form標簽內容在LocalStorage中。
* 作者：黃金鋒
* 版本：version 2.0
*/
define(function () {
//從localStorage中加載數據
function onload(form) {
var fh = form_handler;
var p = fh.getParams(form);
if (!p.bimId || !p.formId || !p.iid) {
return;
}
var id = 'FORM_' + DCI.LoginUser.UserId + '_' + p.bimId + '_' + p.formId + '_' + p.iid;
//alert(id);
var formDataDb;
var allControl = $(form).find("input:text[name],textarea[name]");
//從本地取
var storage = localStorage.getItem(id);
if (storage != null) {
var myData = JSON.parse(storage);
allControl.each(function (i, e) {
var name = $(e).attr("name");
if (myData[name] != null) {
$(e).val(myData[name]);
$(e).change();
}
});
}
//綁定change事件
allControl.each(function (i, el) {
var name = $(el).attr('name');
if (name) {
$(el).on('change', function () {
onchange(this);
});
}
});
//保存修改的數據
function onchange(el) {
var storage = localStorage.getItem(id);
if (storage == null) {
formDataDb = new Object();
var key = $(el).attr("name");
var value = $(el).val();
formDataDb[key] = value;
localStorage.setItem(id, JSON.stringify(formDataDb));
} else {
var myData = JSON.parse(storage);
var key = $(el).attr("name");
var value = $(el).val();
myData[key] = value;
localStorage.setItem(id, JSON.stringify(myData));
}
}
};
//刪除localStorage中的數據
function onsave(form) {
var fh = form_handler;
var p = fh.getParams(form);
var id = 'FORM_' + DCI.LoginUser.UserId + '_' + p.bimId + '_' + p.formId + '_' + p.iid;
localStorage.removeItem(id);
var allGrid = $(form).find(".form-table");
var formId = $(form).data("formid");
allGrid.each(function (index,element) {
var formName = $(element).find("input:hidden[data-formid]").attr("name");
var storageKey = "FORM_" + formId + "_" + formName;
localStorage.removeItem(storageKey);
});
}
return {
onload: onload,
onsave: onsave,
}
});
表單都是自動通過模版生成的，這里附上表單加載需要的form.js.
下面是完成Grid數據保存的js.
/**
* 功能：保存用戶修改完form標簽內容在LocalStorage中。
* 作者：黃金鋒 (549387177@qq.com)
* 日期：2015-11-1 11:14:01
* 修改：2015-11-19 16:09:00
* 版本：version 3.0
*/
define(function () {
//從localStorage中加載數據
function onload(form) {
var fh = form_handler;
var p = fh.getParams(form);
if (!p.bimId || !p.formId || !p.iid) {
return;
}
var id = 'FORM_' + DCI.LoginUser.UserId + '_' + p.bimId + '_' + p.formId + '_' + p.iid;
var formDataDb;
var allControl = $(form).find("input:text[name],textarea[name]");
//從本地取
var storage = localStorage.getItem(id);
if (storage != null)
{
if (confirm("是否加載緩存數據")) {
var myData = JSON.parse(storage);
allControl.each(function (i, e) {
var name = $(e).attr("name");
if (myData[name] != null) {
$(e).val(myData[name]);
$(e).change();
}
});
}
}
var allGrid = $(form).find(".form-table");
var formId = $(form).data("formid");
var formStorage= localStorage.getItem("FORM_" + formId + "_isGridData");
if (formStorage=="1")
{
if (confirm("是否加載Grid緩存數據"))
{
//給Grid控件賦值
allGrid.each(function (index, element) {
var formName = $(element).find("input:hidden[data-formid]").attr("name");
var ipt = $(element).find("input[name]");
var table = $(element).find("input:hidden[data-formid]").siblings(".form-table-body").find(".table-hover");
var storageKey = "FORM_" + formId + "_" + formName;
var data = localStorage.getItem(storageKey);
var myData = JSON.parse(data);
if (myData != null) {
alert(data);
var InsertTotal = myData["Total"]["InsertTotal"];
var DelTotal = myData["Total"]["DelTotal"];
var UpdateTotal = myData["Total"]["UpdateTotal"];
var trIIDIndex = myData["trIIDIndex"]["IID"];
if (InsertTotal > 0) {
for (var i = 0; i < InsertTotal; i++) {
var tr = $('<tr></tr>');
var row_data = myData["Insert"][i];
table.find('colgroup col').each(function (idx, el) {
var td = $('<td></td>');
if (idx == 0) {
td.append('<span class="glyphicon glyphicon-edit" aria-hidden="true"></span>');
td.addClass('form-table-edit');
}
else {
var index = $(el).data('index');
var type = $(el).data('type')
if (type == "RowNumber") {
var val = row_data["RowNumber"];
td.html(val);
}
if (type == "CheckBox") {
var val = row_data[index];
td.append('<input type="checkbox" value="' + val + '" ' + (val == '1' ? 'checked="checked"' : '') + ' />');
}
if (index && type != "CheckBox") {
td.html(row_data[index]);
}
}
if ($(el).attr('width') == '0')
td.addClass('hidden');
td.appendTo(tr);
});
//table.find("tbody").append(tr);
table.append(tr);
tr.data("insert", true);
ipt.change();
}
}
if (UpdateTotal > 0) {
for (var i = 0; i < UpdateTotal; i++) {
var row_data = myData["Update"][i];
var trIID = row_data["trIID"];
var trIndex;
table.find("tr").each(function (idx, ele)
{
var iid = $(ele).find("td").eq(trIIDIndex).html();
if (iid == trIID) {
trIndex = idx;
}
});
var cells = table.find("tr").eq(trIndex);
table.find('colgroup col').each(function (idx, el)
{
var index = $(el).data('index');
if (index)
{
var td = cells.find("td").eq(idx);
var type = $(el).data('type');
var test =new Object();
var text = row_data[index];
if (type == 'CheckBox')
{
var ck = td.find('input[type="checkbox"]');
if (text == '1')
ck.prop('checked', true);
else
ck.prop('checked', false);
}
else
{
td.text(text);
}
}
});
cells.data("update", true);
ipt.change();
}
}
if (DelTotal > 0) {
for (var i = 0; i < DelTotal; i++) {
var row_data = myData["Del"][i];
var trIID = row_data["trIID"];
table.find("tr").each(function (idx,ele) {
var iid = $(ele).find("td").eq(trIIDIndex).html();
if ( iid== trIID)
{
$(this).css("display", "none");
$(this).data("delete", true);
ipt.change();
}
});
}
}
}
});
}
}
//綁定change事件
allControl.each(function (i, el) {
var name = $(el).attr('name');
if (name) {
$(el).on('change', function () {
onchange(this);
});
}
});
//保存修改的數據
function onchange(el) {
var storage = localStorage.getItem(id);
if (storage == null) {
formDataDb = new Object();
var key = $(el).attr("name");
var value = $(el).val();
formDataDb[key] = value;
localStorage.setItem(id, JSON.stringify(formDataDb));
} else {
var myData = JSON.parse(storage);
var key = $(el).attr("name");
var value = $(el).val();
myData[key] = value;
localStorage.setItem(id, JSON.stringify(myData));
}
}
};
//刪除localStorage中的數據
function onsave(form) {
var fh = form_handler;
var p = fh.getParams(form);
var id = 'FORM_' + DCI.LoginUser.UserId + '_' + p.bimId + '_' + p.formId + '_' + p.iid;
localStorage.removeItem(id);
var allGrid = $(form).find(".form-table");
var formId = $(form).data("formid");
allGrid.each(function (index,element) {
var formName = $(element).find("input:hidden[data-formid]").attr("name");
var storageKey = "FORM_" + formId + "_" + formName;
localStorage.removeItem(storageKey);
});
localStorage.setItem("FORM_" + formId + "_isGridData", null);
}
function ongridadd(form, table, data, tr) {
var inputflag = table.closest("div .form-table").find("input:hidden[data-formid]")
var storageKey;
var formId = $(form).data("formid");;
localStorage.setItem("FORM_" + formId + "_isGridData", "1");
var RowNumber = table.find(".active").children().eq(1).html();
var trIIDIndex;
var trIID;
table.find("col").each(function (idx, ele) {
if ($(ele).data("index") == "IID") {
trIID = table.find(".active").children().eq(idx).html();
trIIDIndex = idx;
}
});
var InsertObj = { trIID: trIID, RowNumber: RowNumber };
var columnArr = table.children().find("[data-index]");
if (columnArr) {
columnArr.each(function (index, element) {
var flag = $(element).data("index");
InsertObj[flag] = data[flag];
});
}
if (inputflag && trIID)
{
storageKey = "FORM_" + formId + "_" + inputflag.attr("name");
//var mydata = "{'Insert':[{'trIID':'1','ID':'test','IID':'測試'},{'trIID':'2','ID':'test2','IID':'測試2'}],'Update':[{'trIID':'3','ID':'test3','IID':'測試3'},{'trIID':'4','ID':'test4','IID':'測試4'}],'Del':[{'trIID':'1'},{'trIID':'2'}]}";
var getLocalStorage = localStorage.getItem(storageKey);
if (getLocalStorage) {
var dataObj = JSON.parse(getLocalStorage);
var InsertTotal = dataObj["Total"]["InsertTotal"];
dataObj["Insert"][InsertTotal] = InsertObj;
dataObj["Total"]["InsertTotal"] = InsertTotal + 1;
localStorage.setItem(storageKey, JSON.stringify(dataObj));
} else
{
var mydata = { Total: { InsertTotal: 1, UpdateTotal: 0, DelTotal: 0 }, Insert: [InsertObj], Update: [], Del: [], Notes: { storageKey: storageKey }, trIIDIndex: { IID: trIIDIndex } };
localStorage.setItem(storageKey, JSON.stringify(mydata));
}
}
}
function ongridedit(form, table, data, tr) {
var inputflag = table.closest("div .form-table").find("input:hidden[data-formid]")
var formId = $(form).data("formid");
var storageKey = "FORM_" + formId + "_" + inputflag.attr("name");
localStorage.setItem("FORM_" + formId + "_isGridData", "1");
var mySourceData = {};
var trIIDIndex;
table.find("col").each(function (idx, ele)
{
var index = $(ele).data("index");
var type = $(ele).data("type");
if (index)
{
if (type == "CheckBox")
{
var val = table.find(".active").children().eq(idx).html();
var value =$(val).val();
mySourceData[index] = value;
}
else
{
if (index == "IID")
{
trIIDIndex = idx;
}
mySourceData[index] = table.find(".active").children().eq(idx).html();
}
}
});
var trIID = mySourceData["IID"];
var UpdateObj = { trIID: trIID };
$.extend(UpdateObj, mySourceData);
var getLocalStorage = localStorage.getItem(storageKey);
if (getLocalStorage)
{
var dataObj = JSON.parse(getLocalStorage);
var InsertTotal = dataObj["Total"]["InsertTotal"];
var UpdateTotal = dataObj["Total"]["UpdateTotal"];
if (InsertTotal > 0)//新增后在編輯
{
for (var i = 0; i < InsertTotal; i++) {
var row_data = dataObj["Insert"][i];
if (row_data["trIID"] == trIID) {
$.extend(dataObj["Insert"][i], UpdateObj);
}
}
}
if (UpdateTotal > 0)//編輯之后在編輯
{
for (var i = 0; i < UpdateTotal; i++) {
var row_data = dataObj["Update"][i];
if (row_data["trIID"] == trIID) {
$.extend(dataObj["Update"][i], UpdateObj);
}
}
}
var UpdateTotal = dataObj["Total"]["UpdateTotal"];
dataObj["Update"][UpdateTotal] = UpdateObj;
dataObj["Total"]["UpdateTotal"] = UpdateTotal + 1;
localStorage.setItem(storageKey, JSON.stringify(dataObj));
}
else
{
var mydata = { Total: { InsertTotal: 0, UpdateTotal: 1, DelTotal: 0 }, Insert: [], Update: [UpdateObj], Del: [], Notes: { storageKey: storageKey }, trIIDIndex: { IID: trIIDIndex } };
localStorage.setItem(storageKey, JSON.stringify(mydata));
}
var testdata = localStorage.getItem(storageKey);
var myData = JSON.parse(testdata);
if (testdata != null) {
alert(testdata);
//alert(mydata);
//alert(myData["Total"]["InsertTotal"]);
//alert(myData["Insert"][0]["ID"]);
}
}
function ongriddel(form, table, tr) {
var inputflag = table.closest("div .form-table").find("input:hidden[data-formid]")
var formId = $(form).data("formid");
var storageKey = "FORM_" + formId + "_" + inputflag.attr("name");;
localStorage.setItem("FORM_" + formId + "_isGridData", "1");
var trIIDIndex;
var trIID;
table.find("col").each(function (idx, ele) {
if ($(ele).data("index") == "IID")
{
trIIDIndex = idx;
trIID = tr.find("td").eq(idx).html();
}
});
var DelObj = { trIID: trIID };
var getLocalStorage = localStorage.getItem(storageKey);
if (getLocalStorage) {
var dataObj = JSON.parse(getLocalStorage);
var isInsertData = false;
var isUpdateDel = false;
var InsertTotal = dataObj["Total"]["InsertTotal"];
var DelTotal = dataObj["Total"]["DelTotal"];
var UpdateTotal = dataObj["Total"]["UpdateTotal"];
if (InsertTotal > 0) {
for (var i = 0; i < InsertTotal; i++) {
var row_data = dataObj["Insert"][i];
if (row_data["trIID"] == trIID) {
isInsertData = true;
dataObj["Insert"][i] = null;
}
}
}
if (UpdateTotal>0)
{
for (var i = 0; i < UpdateTotal; i++) {
var row_data = dataObj["Update"][i];
if (row_data["trIID"] == trIID) {
isUpdateDel = true;
dataObj["Update"][i] = null;
}
}
}
if (isInsertData)
{
var tempArr = [];
for (var i = 0; i < InsertTotal; i++) {
if (dataObj["Insert"][i] != null) {
tempArr[i]=dataObj["Insert"][i];
}
}
dataObj["Insert"] = tempArr;
dataObj["Total"]["InsertTotal"] = InsertTotal - 1;
}
else
{
if (isUpdateDel)
{
var tempArr = [];
for (var i = 0; i < InsertTotal; i++) {
if (dataObj["Update"][i] != null) {
tempArr[i] = dataObj["Update"][i];
}
}
dataObj["Update"] = tempArr;
dataObj["Total"]["UpdateTotal"] = UpdateTotal - 1;
}
dataObj["Del"][DelTotal] = DelObj;
dataObj["Total"]["DelTotal"] = DelTotal + 1;
}
localStorage.setItem(storageKey, JSON.stringify(dataObj));
if (dataObj["Total"]["InsertTotal"] == 0 && dataObj["Total"]["UpdateTotal"] == 0 && dataObj["Total"]["DelTotal"] == 0)
{
localStorage.setItem("FORM_" + formId + "_isGridData", null);
}
} else
{
var mydata = { Total: { InsertTotal: 0, UpdateTotal: 0, DelTotal: 1 }, Insert: [], Update: [], Del: [DelObj], Notes: { storageKey: storageKey }, trIIDIndex: { IID: trIIDIndex } };
localStorage.setItem(storageKey, JSON.stringify(mydata));
}
}
return {
onload: onload,
onsave: onsave,
ongridadd: ongridadd,
ongridedit: ongridedit,
ongriddel: ongriddel
}
});
