Ðóññêèé
Êðîñ-áðàóçåðíà àâòîìàòèçàö³ÿ AJAX.
Ó äàí³é ñòàòò³ îïèñàíèé ìåõàí³çì àñèíõðîííîãî
«ñï³ëêóâàííÿ» ç ñåðâåðîì çà äîïîìîãîþ AJAX (
///////////////////AJAX START//////////////////////////
//Ôóíêö³ÿ ÿêà ñòâîðþº òà ïîâåðòຠîá’ºêò XMLHttpRequest äëÿ ðåàë³çàö³¿ AJAX-çàïèò³â
function createXmlHttpRequestObject(){
var xmlHttp;
try {xmlHttp = new XMLHttpRequest();}
catch(e)
{
var XmlHttpVersions = new Array("MSXML2.XMLHTTP.6.0", "MSXML2.XMLHTTP.5.0", "MSXML2.XMLHTTP.4.0", "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP", "Microsoft.XMLHTTP");
for (var i=0; i<XmlHttpVersions.length && !xmlHttp; i++){
try{xmlHttp = new ActiveXObject(XmlHttpVersions[i]);}
catch (e) {}
}
}
if(!xmlHttp)alert("Error creating the XMLHttpRequest object.");
else return(xmlHttp);
}
//Ôóíêö³ÿ âèêîíóº â³äïðàâëåííÿ äàíèõ òà ïåðåíàïðàâëÿº íà ôóíêö³þ-îáðîáíèê ïðè îòðèìàíí³ â³äïîâ³ä³ ç ñåðâåðó.
requestXmlHttp = function(obj/*îá’ºêò XMLHttpRequest */,url/*Àäðåñà ñêðèïòà, ôàéëà, ñòîð³íêè äî ÿêî¿ çâåðòàºìîñü*/,hFunction/*Ôóíêö³ÿ-îáðîáíèê*/,method/*Ìåòîä ïåðåäà÷³ äàíèõ p=POST, g=GET*/,values/*Ðÿäîê ç ïàðàìåòðàìè (äàíèìè) ÿê³ íåîáõ³äíî ïåðåäàòè íà ñåðâåð*/){
if(obj){
try{
if(obj.readyState == 4 || obj.readyState == 0){
method = (method=='g')?'GET':'POST';
values = (values)?values:(method=='POST')?'':null;
obj.open(method, url, true);
obj.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
obj.send(values);
obj.onreadystatechange = function(){recieveXmlHttp(obj,hFunction);};
}
}
catch(e){ }
}
};
//Ôóíêö³ÿ ÿêà ïåðåâ³ðÿº ñòàí â³äïîâ³ä³ readyState, òà ÿêùî âñå íîìàëüíî – âèêëèêຠôóíêö³þ-îáðîáíèê.
recieveXmlHttp = function(obj,f){
if(!obj)return 1;
if (obj.readyState == 4) {
if (obj.status == 200) {
try {
response=obj.responseText;//³äïîâ³äü ó ôîðì³ òåêñòó
if(response!=''){f(response,obj.responseXML}//³äïîâ³äü ó ôîðìàò³ XML
}
catch(e){}
}
else {alert(obj.statusText);}
}
};
/////////////////// AJAX END//////////////////////////
Ïðèêëàä 1: Îíîâëåííÿ êóðñó âàëþò çà äîïîìîãîþ AJAX
//Ñòâîðþºìî îá’ºêò
XmlHttpCourse = createXmlHttpRequestObject();
//Çâåðíåííÿ äî ñåðâåðó
function checkcours(){
requestXmlHttp(XmlHttpCourse,"course.xml",appendCheckcours,'g','');
}
//Îáðîáêà ïîâåðíåíèõ äàíèõ
function appendCheckcours(cont,rXML)
{
if(!cont)return false;
try{USD = rXML.getElementsByTagName('USD').item(0).firstChild.data;}
catch(e){ USD = false;}
try{EUR = rXML.getElementsByTagName('EUR').item(0).firstChild.data;}
catch(e){ EUR = false;}
d.getElementById('cusd').innerHTML = (USD)?((USD/1)?parseFloat(USD).toFixed(3):rcV.USD):'...';
d.getElementById('ceur').innerHTML = (EUR)?((EUR/1)?parseFloat(EUR).toFixed(3):rcV.EUR):'...';
}
Ïðèêëàä 2: Äèíàì³÷íå çàâàíòàæåííÿ çì³ñòó
//Ñòâîðþºìî îá’ºêò
XmlHttpContent = createXmlHttpRequestObject();
//Çâåðíåííÿ äî ñåðâåðó
function loadcontent(num){
requestXmlHttp(XmlHttpContent,"indention"+num+".txt",function(cont){appendIndention(num,cont)},'g','');
d.getElementById('indention'+num).innerHTML = "Çàâàíòàæåííÿ...";
}
//Îáðîáêà ïîâåðíåíèõ äàíèõ
function appendIndention(num,content)
{
if(!content)return false;
d.getElementById('indention'+num).innerHTML = content;
}