本文討論了treefilter實現tree的查詢，和後臺返回路徑的方式，來實現對extjs tree的搜索。
介紹部分內容來源網絡，先謝謝該作者。
在任何一個Tree樹中，提供查找功能無疑會大大方便用戶。不用睜大眼睛一級一級去展開，只要輸入關鍵字，回車就能自動定位到節點，豈不快哉？然後再次回車查找下一個。這樣的用戶體驗是相當完美的 ( 見《用戶體驗這點事兒》)。但在動態異步加載的Tree樹中，客戶端實現這樣的功能就有點困難，因爲節點是異步動態加載的。默認是沒有全部從服務器端取回的，通常的做法是默認加載第一級，其他級的節點都是惰性按需加載的，用戶點了纔會展開。而對於這個沒有完全加載的樹，用戶希望搜索節點，怎麼實現？笨辦法是先展開樹的所有節點，然後再在樹中搜索。這樣的話在服務器數據量大的情況下會非常慢。這裏的實現方法是在服務器端的WebService查找，通過AJAX返回第一個匹配節點的路徑Path，然後展開這個路徑，選中這個搜索到節點。查找下一個（FindNext）的實現方法是…
(提供查找功能的樹Tree無疑會大大方便用戶)
在任何一個Tree樹中，提供查找功能無疑會大大方便用戶。不用睜大眼睛一級一級去展開，只要輸入關鍵字，回車就能自動定位到節點，豈不快哉？然後再次回車查找下一個。這樣的用戶體驗是相當完美的。
但在動態異步加載的Tree樹中，客戶端實現這樣的功能就有點困難，因爲節點是異步動態加載的。默認是沒有全部從服務器端取回的，通常的做法是默認加載第一級，其他級的節點都是惰性按需加載的，用戶點了纔會展開。而對於這個沒有完全加載的樹，用戶希望搜索節點，怎麼實現？笨辦法是先展開樹的所有節點，然後再在樹中搜索。這樣的話在服務器數據量大的情況下會非常慢。
這裏的實現方法是在服務器端的WebService查找，通過AJAX返回第一個匹配節點的路徑Path，然後展開這個路徑，選中這個搜索到節點。
在ExtJS中，AsyncTreeNode是異步節點，TreeLoader實現對樹結點的異步加載，即使服務器取到大量的數據，也沒有問題，異步加載能保證性能和節點的按需加載。服務端需要生成指定格式的Json字符串。
首先這兒有一個extjs的動態樹，默認加載第一級，其他的級按需加載。（由於工程文件太大，s2sh+oracle，後臺代碼不提供。）下面給出利用treefilter和返回展開路徑的web端代碼：
dymicTree是一個treePanel，動態樹。
var timeOutId = null;
/**
* 定義一個treefilter，採用第一種方式對動態樹進行過濾，當然首先要展開樹
* @author centre
*/
var treeFilter = new Ext.tree.TreeFilter(dymicTree, {
clearBlank : true,
autoClear : true
});
// 保存上次隱藏的空節點
var hiddenPkgs = [];
/**
* 通過關鍵字查找樹的節點，並定位，這兒有2種實現方式， 1.通過treeFilter，當數據量小的時候是可行的 2.通過返回tree路徑，對應數據量大的時候
*
* @param {}
* node
* @param {}
* event
* @author centre
*/
var findByKeyWordFiler = function(node, event) {
// 清除timeOutId
clearTimeout(timeOutId);
// 展開樹節點
dymicTree.expandAll();
// 爲了避免重複的訪問後臺，給服務器造成的壓力，採用timeOutId進行控制，如果採用treeFilter也可以造成重複的keyup
timeOutId = setTimeout(function() {
// 獲取輸入框的值。
var text = node.getValue();
// 根據輸入製作一個正則表達式，'i'代表不區分大小寫
var re = new RegExp(Ext.escapeRe(text), 'i');
// 先要顯示上次隱藏掉的節點
Ext.each(hiddenPkgs, function(n) {
n.ui.show();
});
hiddenPkgs = [];
if (text != "") {
treeFilter.filterBy(function(n) {
// 只過濾葉子節點，這樣省去枝幹被過濾的時候，底下的葉子都無法顯示
return !n.isLeaf() || re.test(n.text);
});
// 如果這個節點不是葉子，而且下面沒有子節點，就應該隱藏掉
dymicTree.root.cascade(function(n) {
if(n.id!='0'){
if(!n.isLeaf() &&judge(n,re)==false&& !re.test(n.text)){
hiddenPkgs.push(n);
n.ui.hide();
}
}
});
} else {
treeFilter.clear();
return;
}
}, 500);
}
//過濾不匹配的非葉子節點或者是葉子節點
/**
*
* @param {Object} n
* @param {Object} re
* @return {TypeName}
* @author yang
*/
var judge =function(n,re){
var str=false;
n.cascade(function(n1){
if(n1.isLeaf())
{
if(re.test(n1.text)){str=true;return;}
}
else{
if(re.test(n1.text)){str=true;return;}
}
});
return str;
};
/**
* 根據路徑展開節點後，選中該節點
* @param {} bSuccess
* @param {} oLastNode
*/
function onExpandPathComplete(bSuccess, oLastNode) {
if (!bSuccess)
return;
// focus 節點，並選中節點！
selectNode(oLastNode);
}
/**
* 選中傳入的節點，並單擊此節點
*
* @param {}
* node 傳入節點對象
* @author centre
*/
var selectNode = function(node) {
node.ensureVisible();
node.select();
node.fireEvent('click', node);
}
/**
* 通過關鍵字查找樹的節點，並定位，這兒有2種實現方式， 1.通過treeFilter，當數據量小的時候是可行的 2.通過返回tree路徑，對應數據量大的時候
* 支持模糊查詢
*
* @param {}
* node
* @param {}
* event
* @author centre
*/
var findByKeyWordPath = function(node, event) {
// 清除timeOutId
clearTimeout(timeOutId);
timeOutId = setTimeout(function() {
// 獲取輸入框的值。
var text = node.getValue().trim();
// 採用ajax獲得需要展開的路徑
if (text != "") {
Ext.Ajax.request({
url : 'jsps/servlet/findByKeyword.jsp',
success : function(response, opts) {
var obj = Ext.decode(response.responseText);
var length = obj.record.length;
dymicTree.root.reload();
for (var i = 0; i < length; i++) {
var path = obj.record[i].path;
dymicTree.expandPath(path,'id',onExpandPathComplete);
}
},
failure : function(response, opts) {
Ext.Msg.alert("錯誤提示", "請求失敗,請與開發人員聯繫。")
.setIcon(Ext.MessageBox.ERROR);
},
params : {
keyWord : text
}
});
} else {
// Ext.Msg.alert("信息",
// "請輸入關鍵字").setIcon(Ext.MessageBox.INFO);
// return;
}
}, 500);
}
/**
* 給輸入框綁定keyup事件，需要加上enableKeyEvents:true才能讓extjs的textfield代理 鼠標事件
*
* @author centre
*/
searchBox.findById("keyWord").on("keyup", function(node, event) {
findByKeyWordFiler(node, event);
});
以下是extjs官方幫助文檔的代碼，可以參考：
Ext.BLANK_IMAGE_URL = 'resources/s.gif';
Docs = {};
ApiPanel = function() {
ApiPanel.superclass.constructor.call(this, {
id:'api-tree',
region:'west',
split:true,
header: false,
width: 280,
minSize: 175,
maxSize: 500,
collapsible: true,
margins:'0 0 5 5',
cmargins:'0 0 0 0',
rootVisible:false,
lines:false,
autoScroll:true,
animCollapse:false,
animate: false,
collapseMode:'mini',
loader: new Ext.tree.TreeLoader({
preloadChildren: true,
clearOnLoad: false
}),
root: new Ext.tree.AsyncTreeNode({
text:'Ext JS',
id:'root',
expanded:true,
children:[Docs.classData]
}),
collapseFirst:false
});
// no longer needed!
//new Ext.tree.TreeSorter(this, {folderSort:true,leafAttr:'isClass'});
this.getSelectionModel().on('beforeselect', function(sm, node){
return node.isLeaf();
});
};
Ext.extend(ApiPanel, Ext.tree.TreePanel, {
initComponent: function(){
this.hiddenPkgs = [];
Ext.apply(this, {
tbar:[ ' ',
new Ext.form.TextField({
width: 200,
emptyText:'Find a Class',
enableKeyEvents: true,
listeners:{
render: function(f){
this.filter = new Ext.tree.TreeFilter(this, {
clearBlank: true,
autoClear: true
});
},
keydown: {
fn: this.filterTree,
buffer: 350,
scope: this
},
scope: this
}
}), ' ', ' ',
{
iconCls: 'icon-expand-all',
tooltip: 'Expand All',
handler: function(){ this.root.expand(true); },
scope: this
}, '-', {
iconCls: 'icon-collapse-all',
tooltip: 'Collapse All',
handler: function(){ this.root.collapse(true); },
scope: this
}]
})
ApiPanel.superclass.initComponent.call(this);
},
filterTree: function(t, e){
var text = t.getValue();
Ext.each(this.hiddenPkgs, function(n){
n.ui.show();
});
if(!text){
this.filter.clear();
return;
}
this.expandAll();
var re = new RegExp('^' + Ext.escapeRe(text), 'i');
this.filter.filterBy(function(n){
return !n.attributes.isClass || re.test(n.text);
});
// hide empty packages that weren't filtered
this.hiddenPkgs = [];
var me = this;
this.root.cascade(function(n){
if(!n.attributes.isClass && n.ui.ctNode.offsetHeight < 3){
n.ui.hide();
me.hiddenPkgs.push(n);
}
});
},
selectClass : function(cls){
if(cls){
var parts = cls.split('.');
var last = parts.length-1;
var res = [];
var pkg = [];
for(var i = 0; i < last; i++){ // things get nasty - static classes can have .
var p = parts[i];
var fc = p.charAt(0);
var staticCls = fc.toUpperCase() == fc;
if(p == 'Ext' || !staticCls){
pkg.push(p);
res[i] = 'pkg-'+pkg.join('.');
}else if(staticCls){
--last;
res.splice(i, 1);
}
}
res[last] = cls;
this.selectPath('/root/apidocs/'+res.join('/'));
}
}
});
DocPanel = Ext.extend(Ext.Panel, {
closable: true,
autoScroll:true,
initComponent : function(){
var ps = this.cclass.split('.');
this.title = ps[ps.length-1];
Ext.apply(this,{
tbar: ['->',{
text: 'Config Options',
handler: this.scrollToMember.createDelegate(this, ['configs']),
iconCls: 'icon-config'
},'-',{
text: 'Properties',
handler: this.scrollToMember.createDelegate(this, ['props']),
iconCls: 'icon-prop'
}, '-',{
text: 'Methods',
handler: this.scrollToMember.createDelegate(this, ['methods']),
iconCls: 'icon-method'
}, '-',{
text: 'Events',
handler: this.scrollToMember.createDelegate(this, ['events']),
iconCls: 'icon-event'
}, '-',{
text: 'Direct Link',
handler: this.directLink,
scope: this,
iconCls: 'icon-fav'
}, '-',{
tooltip:'Hide Inherited Members',
iconCls: 'icon-hide-inherited',
enableToggle: true,
scope: this,
toggleHandler : function(b, pressed){
this.body[pressed ? 'addClass' : 'removeClass']('hide-inherited');
}
}, '-', {
tooltip:'Expand All Members',
iconCls: 'icon-expand-members',
enableToggle: true,
scope: this,
toggleHandler : function(b, pressed){
this.body[pressed ? 'addClass' : 'removeClass']('full-details');
}
}]
});
DocPanel.superclass.initComponent.call(this);
},
directLink : function(){
var link = String.format(
"<a href=\"{0}\" target=\"_blank\">{0}</a>",
document.location.href+'?class='+this.cclass
);
Ext.Msg.alert('Direct Link to ' + this.cclass,link);
},
scrollToMember : function(member){
var el = Ext.fly(this.cclass + '-' + member);
if(el){
var top = (el.getOffsetsTo(this.body)[1]) + this.body.dom.scrollTop;
this.body.scrollTo('top', top-25, {duration:0.75, callback: this.hlMember.createDelegate(this, [member])});
}
},
scrollToSection : function(id){
var el = Ext.getDom(id);
if(el){
var top = (Ext.fly(el).getOffsetsTo(this.body)[1]) + this.body.dom.scrollTop;
this.body.scrollTo('top', top-25, {duration:0.5, callback: function(){
Ext.fly(el).next('h2').pause(0.2).highlight('#8DB2E3', {attr:'color'});
}});
}
},
hlMember : function(member){
var el = Ext.fly(this.cclass + '-' + member);
if(el){
if (tr = el.up('tr')) {
tr.highlight('#cadaf9');
}
}
}
});
MainPanel = function(){
this.searchStore = new Ext.data.Store({
proxy: new Ext.data.ScriptTagProxy({
url: 'http://extjs.com/playpen/api.php'
}),
reader: new Ext.data.JsonReader({
root: 'data'
},
['cls', 'member', 'type', 'doc']
),
baseParams: {},
listeners: {
'beforeload' : function(){
this.baseParams.qt = Ext.getCmp('search-type').getValue();
}
}
});
MainPanel.superclass.constructor.call(this, {
id:'doc-body',
region:'center',
margins:'0 5 5 0',
resizeTabs: true,
minTabWidth: 135,
tabWidth: 135,
plugins: new Ext.ux.TabCloseMenu(),
enableTabScroll: true,
activeTab: 0,
items: {
id:'welcome-panel',
title: 'API Home',
autoLoad: {url: 'welcome.html', callback: this.initSearch, scope: this},
iconCls:'icon-docs',
autoScroll: true,
tbar: [
'Search: ', ' ',
new Ext.ux.SelectBox({
listClass:'x-combo-list-small',
width:90,
value:'Starts with',
id:'search-type',
store: new Ext.data.SimpleStore({
fields: ['text'],
expandData: true,
data : ['Starts with', 'Ends with', 'Any match']
}),
displayField: 'text'
}), ' ',
new Ext.app.SearchField({
width:240,
store: this.searchStore,
paramName: 'q'
})
]
}
});
};
Ext.extend(MainPanel, Ext.TabPanel, {
initEvents : function(){
MainPanel.superclass.initEvents.call(this);
this.body.on('click', this.onClick, this);
},
onClick: function(e, target){
if(target = e.getTarget('a:not(.exi)', 3)){
var cls = Ext.fly(target).getAttributeNS('ext', 'cls');
e.stopEvent();
if(cls){
var member = Ext.fly(target).getAttributeNS('ext', 'member');
this.loadClass(target.href, cls, member);
}else if(target.className == 'inner-link'){
this.getActiveTab().scrollToSection(target.href.split('#')[1]);
}else{
window.open(target.href);
}
}else if(target = e.getTarget('.micon', 2)){
e.stopEvent();
var tr = Ext.fly(target.parentNode);
if(tr.hasClass('expandable')){
tr.toggleClass('expanded');
}
}
},
loadClass : function(href, cls, member){
var id = 'docs-' + cls;
var tab = this.getComponent(id);
if(tab){
this.setActiveTab(tab);
if(member){
tab.scrollToMember(member);
}
}else{
var autoLoad = {url: href};
if(member){
autoLoad.callback = function(){
Ext.getCmp(id).scrollToMember(member);
}
}
var p = this.add(new DocPanel({
id: id,
cclass : cls,
autoLoad: autoLoad,
iconCls: Docs.icons[cls]
}));
this.setActiveTab(p);
}
},
initSearch : function(){
// Custom rendering Template for the View
var resultTpl = new Ext.XTemplate(
'<tpl for=".">',
'<div class="search-item">',
'<a class="member" ext:cls="{cls}" ext:member="{member}" href="output/{cls}.html">',
'<img src="../resources/images/default/s.gif" class="item-icon icon-{type}"/>{member}',
'</a> ',
'<a class="cls" ext:cls="{cls}" href="output/{cls}.html">{cls}</a>',
'<p>{doc}</p>',
'</div></tpl>'
);
var p = new Ext.DataView({
applyTo: 'search',
tpl: resultTpl,
loadingText:'Searching...',
store: this.searchStore,
itemSelector: 'div.search-item',
emptyText: '<h3>Use the search field above to search the Ext API for classes, properties, config options, methods and events.</h3>'
});
},
doSearch : function(e){
var k = e.getKey();
if(!e.isSpecialKey()){
var text = e.target.value;
if(!text){
this.searchStore.baseParams.q = '';
this.searchStore.removeAll();
}else{
this.searchStore.baseParams.q = text;
this.searchStore.reload();
}
}
}
});
Ext.onReady(function(){
Ext.QuickTips.init();
var api = new ApiPanel();
var mainPanel = new MainPanel();
api.on('click', function(node, e){
if(node.isLeaf()){
e.stopEvent();
mainPanel.loadClass(node.attributes.href, node.id);
}
});
mainPanel.on('tabchange', function(tp, tab){
api.selectClass(tab.cclass);
});
var viewport = new Ext.Viewport({
layout:'border',
items:[ {
cls: 'docs-header',
height: 44,
region:'north',
xtype:'box',
el:'header',
border:false,
margins: '0 0 5 0'
}, api, mainPanel ]
});
api.expandPath('/root/apidocs');
// allow for link in
var page = window.location.href.split('?')[1];
if(page){
var ps = Ext.urlDecode(page);
var cls = ps['class'];
mainPanel.loadClass('output/' + cls + '.html', cls, ps.member);
}
viewport.doLayout();
setTimeout(function(){
Ext.get('loading').remove();
Ext.get('loading-mask').fadeOut({remove:true});
}, 250);
});
Ext.app.SearchField = Ext.extend(Ext.form.TwinTriggerField, {
initComponent : function(){
if(!this.store.baseParams){
this.store.baseParams = {};
}
Ext.app.SearchField.superclass.initComponent.call(this);
this.on('specialkey', function(f, e){
if(e.getKey() == e.ENTER){
this.onTrigger2Click();
}
}, this);
},
validationEvent:false,
validateOnBlur:false,
trigger1Class:'x-form-clear-trigger',
trigger2Class:'x-form-search-trigger',
hideTrigger1:true,
width:180,
hasSearch : false,
paramName : 'query',
onTrigger1Click : function(){
if(this.hasSearch){
this.store.baseParams[this.paramName] = '';
this.store.removeAll();
this.el.dom.value = '';
this.triggers[0].hide();
this.hasSearch = false;
this.focus();
}
},
onTrigger2Click : function(){
var v = this.getRawValue();
if(v.length < 1){
this.onTrigger1Click();
return;
}
if(v.length < 2){
Ext.Msg.alert('Invalid Search', 'You must enter a minimum of 2 characters to search the API');
return;
}
this.store.baseParams[this.paramName] = v;
var o = {start: 0};
this.store.reload({params:o});
this.hasSearch = true;
this.triggers[0].show();
this.focus();
}
});
/**
* Makes a ComboBox more closely mimic an HTML SELECT. Supports clicking and dragging
* through the list, with item selection occurring when the mouse button is released.
* When used will automatically set {@link #editable} to false and call {@link Ext.Element#unselectable}
* on inner elements. Re-enabling editable after calling this will NOT work.
*
* @author Corey Gilmore
* http://extjs.com/forum/showthread.php?t=6392
*
* @history 2007-07-08 jvs
* Slight mods for Ext 2.0
*/
Ext.ux.SelectBox = function(config){
this.searchResetDelay = 1000;
config = config || {};
config = Ext.apply(config || {}, {
editable: false,
forceSelection: true,
rowHeight: false,
lastSearchTerm: false,
triggerAction: 'all',
mode: 'local'
});
Ext.ux.SelectBox.superclass.constructor.apply(this, arguments);
this.lastSelectedIndex = this.selectedIndex || 0;
};
Ext.extend(Ext.ux.SelectBox, Ext.form.ComboBox, {
lazyInit: false,
initEvents : function(){
Ext.ux.SelectBox.superclass.initEvents.apply(this, arguments);
// you need to use keypress to capture upper/lower case and shift+key, but it doesn't work in IE
this.el.on('keydown', this.keySearch, this, true);
this.cshTask = new Ext.util.DelayedTask(this.clearSearchHistory, this);
},
keySearch : function(e, target, options) {
var raw = e.getKey();
var key = String.fromCharCode(raw);
var startIndex = 0;
if( !this.store.getCount() ) {
return;
}
switch(raw) {
case Ext.EventObject.HOME:
e.stopEvent();
this.selectFirst();
return;
case Ext.EventObject.END:
e.stopEvent();
this.selectLast();
return;
case Ext.EventObject.PAGEDOWN:
this.selectNextPage();
e.stopEvent();
return;
case Ext.EventObject.PAGEUP:
this.selectPrevPage();
e.stopEvent();
return;
}
// skip special keys other than the shift key
if( (e.hasModifier() && !e.shiftKey) || e.isNavKeyPress() || e.isSpecialKey() ) {
return;
}
if( this.lastSearchTerm == key ) {
startIndex = this.lastSelectedIndex;
}
this.search(this.displayField, key, startIndex);
this.cshTask.delay(this.searchResetDelay);
},
onRender : function(ct, position) {
this.store.on('load', this.calcRowsPerPage, this);
Ext.ux.SelectBox.superclass.onRender.apply(this, arguments);
if( this.mode == 'local' ) {
this.calcRowsPerPage();
}
},
onSelect : function(record, index, skipCollapse){
if(this.fireEvent('beforeselect', this, record, index) !== false){
this.setValue(record.data[this.valueField || this.displayField]);
if( !skipCollapse ) {
this.collapse();
}
this.lastSelectedIndex = index + 1;
this.fireEvent('select', this, record, index);
}
},
render : function(ct) {
Ext.ux.SelectBox.superclass.render.apply(this, arguments);
if( Ext.isSafari ) {
this.el.swallowEvent('mousedown', true);
}
this.el.unselectable();
this.innerList.unselectable();
this.trigger.unselectable();
this.innerList.on('mouseup', function(e, target, options) {
if( target.id && target.id == this.innerList.id ) {
return;
}
this.onViewClick();
}, this);
this.innerList.on('mouseover', function(e, target, options) {
if( target.id && target.id == this.innerList.id ) {
return;
}
this.lastSelectedIndex = this.view.getSelectedIndexes()[0] + 1;
this.cshTask.delay(this.searchResetDelay);
}, this);
this.trigger.un('click', this.onTriggerClick, this);
this.trigger.on('mousedown', function(e, target, options) {
e.preventDefault();
this.onTriggerClick();
}, this);
this.on('collapse', function(e, target, options) {
Ext.getDoc().un('mouseup', this.collapseIf, this);
}, this, true);
this.on('expand', function(e, target, options) {
Ext.getDoc().on('mouseup', this.collapseIf, this);
}, this, true);
},
clearSearchHistory : function() {
this.lastSelectedIndex = 0;
this.lastSearchTerm = false;
},
selectFirst : function() {
this.focusAndSelect(this.store.data.first());
},
selectLast : function() {
this.focusAndSelect(this.store.data.last());
},
selectPrevPage : function() {
if( !this.rowHeight ) {
return;
}
var index = Math.max(this.selectedIndex-this.rowsPerPage, 0);
this.focusAndSelect(this.store.getAt(index));
},
selectNextPage : function() {
if( !this.rowHeight ) {
return;
}
var index = Math.min(this.selectedIndex+this.rowsPerPage, this.store.getCount() - 1);
this.focusAndSelect(this.store.getAt(index));
},
search : function(field, value, startIndex) {
field = field || this.displayField;
this.lastSearchTerm = value;
var index = this.store.find.apply(this.store, arguments);
if( index !== -1 ) {
this.focusAndSelect(index);
}
},
focusAndSelect : function(record) {
var index = typeof record === 'number' ? record : this.store.indexOf(record);
this.select(index, this.isExpanded());
this.onSelect(this.store.getAt(record), index, this.isExpanded());
},
calcRowsPerPage : function() {
if( this.store.getCount() ) {
this.rowHeight = Ext.fly(this.view.getNode(0)).getHeight();
this.rowsPerPage = this.maxHeight / this.rowHeight;
} else {
this.rowHeight = false;
}
}
});
Ext.Ajax.on('requestcomplete', function(ajax, xhr, o){
if(typeof urchinTracker == 'function' && o && o.url){
urchinTracker(o.url);
}
});
