[转载]基于prototype的输入自动提示autocomplete

Autocomplete.prototype = {

killerFn: null,

initialize: function() {
var me = this;
this.killerFn = function(e) {
if (!$(Event.element(e)).up('.autocomplete')) {
me.killSuggestions();
me.disableKillerFn();
}
} .bindAsEventListener(this);

if (!this.options.width) { this.options.width = this.el.getWidth(); }

var div = new Element('div', { style: 'position:absolute;' });
div.update('

');

this.options.container = $(this.options.container);
if (this.options.container) {
this.options.container.appendChild(div);
this.fixPosition = function() { };
} else {
document.body.appendChild(div);
}

this.mainContainerId = div.identify();
this.container = $('Autocomplete_' + this.id);
this.fixPosition();

Event.observe(this.el, window.opera ? 'keypress':'keydown', this.onKeyPress.bind(this));
Event.observe(this.el, 'keyup', this.onKeyUp.bind(this));
Event.observe(this.el, 'blur', this.enableKillerFn.bind(this));
Event.observe(this.el, 'focus', this.fixPosition.bind(this));
this.container.setStyle({ maxHeight: this.options.maxHeight + 'px' });
this.instanceId = Autocomplete.instances.push(this) - 1;
},

fixPosition: function() {
var offset = this.el.cumulativeOffset();
$(this.mainContainerId).setStyle({ top: (offset.top + this.el.getHeight()) + 'px', left: offset.left + 'px' });
},

enableKillerFn: function() {
Event.observe(document.body, 'click', this.killerFn);
},

disableKillerFn: function() {
Event.stopObserving(document.body, 'click', this.killerFn);
},

killSuggestions: function() {
this.stopKillSuggestions();
this.intervalId = window.setInterval(function() { this.hide(); this.stopKillSuggestions(); } .bind(this), 300);
},

stopKillSuggestions: function() {
window.clearInterval(this.intervalId);
},

onKeyPress: function(e) {
if (!this.enabled) { return; }
switch (e.keyCode) {
case Event.KEY_ESC:
this.el.value = this.currentValue;
this.hide();
break;
case Event.KEY_TAB:
case Event.KEY_RETURN:
if (this.selectedIndex === -1) {
this.hide();
return;
}
this.select(this.selectedIndex);
if (e.keyCode === Event.KEY_TAB) { return; }
break;
case Event.KEY_UP:
this.moveUp();
break;
case Event.KEY_DOWN:
this.moveDown();
break;
default:
return;
}
Event.stop(e);
},

onKeyUp: function(e) {
switch (e.keyCode) {
case Event.KEY_UP:
case Event.KEY_DOWN:
return;
}
clearInterval(this.onChangeInterval);
if (this.currentValue !== this.el.value) {
if (this.options.deferRequestBy > 0) {
// Defer lookup in case when value changes very quickly:
this.onChangeInterval = setInterval((function() {
this.onValueChange();
}).bind(this), this.options.deferRequestBy);
} else {
this.onValueChange();
}
}
},

onValueChange: function() {
clearInterval(this.onChangeInterval);
this.currentValue = this.el.value;
this.selectedIndex = -1;
if (this.ignoreValueChange) {
this.ignoreValueChange = false;
return;
}
if (this.currentValue === '' || this.currentValue.length < this.options.minChars) { this.hide(); } else { this.getSuggestions(); } }, getSuggestions: function() { var cr = this.cachedResponse[this.currentValue]; if (cr && Object.isArray(cr.suggestions)) { this.suggestions = cr.suggestions; this.data = cr.data; this.numbers = cr.numbers; this.suggest(); } else if (!this.isBadQuery(this.currentValue)) { new Ajax.Request(this.serviceUrl, { parameters: { query: this.currentValue }, onComplete: this.processResponse.bind(this), method: 'get' }); } }, isBadQuery: function(q) { var i = this.badQueries.length; while (i--) { if (q.indexOf(this.badQueries[i]) === 0) { return true; } } return false; }, hide: function() { this.enabled = false; this.selectedIndex = -1; this.container.hide(); }, suggest: function() { if (this.suggestions.length === 0) { this.hide(); return; } var content = []; var re = new RegExp('\\b' + this.currentValue.match(/[\u4e00-\u9fa5a-zA-Z0-9]+/g).join('|\\b'), 'gi'); var numbersContent = ''; this.suggestions.each(function(value, i) { if (Object.isArray(this.numbers) && this.options.showNumber){ numbersContent = ' 约' + this.numbers[i] + '条';
}
content.push((this.selectedIndex === i ? '

');
} .bind(this));
this.enabled = true;
this.container.update(content.join('')).show();
},

processResponse: function(xhr) {
var response;
try {
response = xhr.responseText.evalJSON();
if (!Object.isArray(response.data)) { response.data = []; }
} catch (err) { return; }
this.cachedResponse[response.query] = response;
if (response.suggestions.length === 0) { this.badQueries.push(response.query); }
if (response.query === this.currentValue) {
this.suggestions = response.suggestions;
this.data = response.data;
this.numbers = response.numbers;
this.suggest();
}
},

activate: function(index) {
var divs = this.container.childNodes;
var activeItem;
// Clear previous selection:
if (this.selectedIndex !== -1 && divs.length > this.selectedIndex) {
divs[this.selectedIndex].className = '';
}
this.selectedIndex = index;
if (this.selectedIndex !== -1 && divs.length > this.selectedIndex) {
activeItem = divs[this.selectedIndex]
activeItem.className = 'selected';
}
return activeItem;
},

deactivate: function(div, index) {
div.className = '';
if (this.selectedIndex === index) { this.selectedIndex = -1; }
},

select: function(i) {
var selectedValue = this.suggestions[i];
if (selectedValue) {
this.el.value = selectedValue;
if (this.options.autoSubmit && this.el.form) {
this.el.form.submit();
}
this.ignoreValueChange = true;
this.hide();
this.onSelect(i);
}
},

moveUp: function() {
if (this.selectedIndex === -1) { return; }
if (this.selectedIndex === 0) {
this.container.childNodes[0].className = '';
this.selectedIndex = -1;
this.el.value = this.currentValue;
return;
}
this.adjustScroll(this.selectedIndex - 1);
},

moveDown: function() {
if (this.selectedIndex === (this.suggestions.length - 1)) { return; }
this.adjustScroll(this.selectedIndex + 1);
},

adjustScroll: function(i) {
var container = this.container;
var activeItem = this.activate(i);
var offsetTop = activeItem.offsetTop;
var upperBound = container.scrollTop;
var lowerBound = upperBound + this.options.maxHeight - 25;
if (offsetTop < upperBound) { container.scrollTop = offsetTop; } else if (offsetTop > lowerBound) {
container.scrollTop = offsetTop - this.options.maxHeight + 25;
}
this.el.value = this.suggestions[i];
},

onSelect: function(i) {
(this.options.onSelect || Prototype.emptyFunction)(this.suggestions[i], this.data[i]);
}

};

Event.observe(document, 'dom:loaded', function(){ Autocomplete.isDomLoaded = true; }, false
[/js]
使用：Event.observe(window, 'load', function() {
[js]
function onAutocompleteSelect(value, data){
//..
}
var rand = new Date().getTime();
var url = 'data.js?r=' + rand;
new Autocomplete('txtEmployeeNum', {
serviceUrl: url,
width: 300, //可选
onSelect: onAutocompleteSelect, //可选
showNumber: true //显示条数
//container: 'ac_container' //可选
});
});

[/js]
data.js 有后台控制，产生json格式数据，如下：
[js]
//{query:'z',suggestions:['z','z1','z2','z3']}

//{query:'q',suggestions:['q','q1','q2','q3'],numbers:[99,88,77,66]}

{query:'去',suggestions:['去','去1','去12','去123'],numbers:[99,88,77,66]}
[/js]
弹出提示层的原型：
[html]