[Javascript] AJAX

AJAX

Asynchronous Javascript And XML

프로그래밍 언어가 X

 

 

# XMLHttpRequest Object

 

variable = new XMLHttpRequest();

 

Send

xhttp.open("GET", "ajax_info.txt", true);
xhttp.send();

 

 

# AJAX Response

 

Property
=> responseText : 자바스크립트 string으로서 server response 리턴
=> responseXML : XML DOM object로서 server response 리턴

 

Method
=> getResponseHeader() : 구체적인 header 정보 리턴
=> getAllResponseHeaders() : 모든 header 정보 리턴

 

const xhttp = new XMLHttpRequest();
xhttp.onload = function() {
    document.getElementById("demo").innerHTML =
    this.getAllResponseHeaders();
}
xhttp.open("GET", "ajax_info.txt");
xhttp.send();

const xhttp = new XMLHttpRequest();
xhttp.onload = function() {
    document.getElementById("demo").innerHTML =
    this.getResponseHeader("Last-Modified");
}
xhttp.open("GET", "ajax_info.txt");
xhttp.send();

 

 

# AJAX PHP

 

<p>Start typing a name in the input field below:</p>
<p>Suggestions: <span id="txtHint"></span></p>

<form>
First name: <input type="text" onkeyup="showHint(this.value)">
</form>

<script>
function showHint(str) {
  if (str.length == 0) { 
    document.getElementById("txtHint").innerHTML = "";
    return;
  } else {
    const xmlhttp = new XMLHttpRequest();
    xmlhttp.onload = function() {
      document.getElementById("txtHint").innerHTML = this.responseText;
    }
  xmlhttp.open("GET", "gethint.php?q=" + str);
  xmlhttp.send();
  }
}
</script>

 

 

# AJAX ASP

 

<p>Start typing a name in the input field below:</p>
<p>Suggestions: <span id="txtHint"></span></p>

<form>
First name: <input type="text" onkeyup="showHint(this.value)">
</form>

<script>
function showHint(str) {
  if (str.length == 0) { 
    document.getElementById("txtHint").innerHTML = "";
    return;
  } else {
    const xmlhttp = new XMLHttpRequest();
    xmlhttp.onload = function() {
      document.getElementById("txtHint").innerHTML = this.responseText;
    }
  xmlhttp.open("GET", "gethint.asp?q=" + str);
  xmlhttp.send();
  }
}
</script>

 

 

# AJAX Database

 

function showCustomer(str) {
  if (str == "") {
    document.getElementById("txtHint").innerHTML = "";
    return;
  }
  const xhttp = new XMLHttpRequest();
  xhttp.onload = function() {
    document.getElementById("txtHint").innerHTML = this.responseText;
  }
  xhttp.open("GET", "getcustomer.php?q="+str);
  xhttp.send();
}

 

 

# XML Application

 

XML Data

<table id="demo"></table>

<script>
function loadXMLDoc() {
  const xmlhttp = new XMLHttpRequest();
  xmlhttp.onload = function() {
    const xmlDoc = xml.responseXML;
    const cd = xmlDoc.getElementsByTagName("CD");
    myFunction(cd);
  }
  xmlhttp.open("GET", "cd_catalog.xml");
  xmlhttp.send();
}

function myFunction(cd) {
  let table="<tr><th>Artist</th><th>Title</th></tr>";
  for (let i = 0; i < cd.length; i++) {
    table += "<tr><td>" +
    cd[i].getElementsByTagName("ARTIST")[0].childNodes[0].nodeValue +
    "</td><td>" +
    cd[i].getElementsByTagName("TITLE")[0].childNodes[0].nodeValue +
    "</td></tr>";
  }
  document.getElementById("demo").innerHTML = table;
}
</script>

</body>
</html>

 

First CD

const xhttp = new XMLHttpRequest();
xhttp.onload = function() {
  const xmlDoc = xhttp.responseXML;
  const cd = xmlDoc.getElementsByTagName("CD");
  myFunction(cd, 0);
}
xhttp.open("GET", "cd_catalog.xml");
xhttp.send();

function myFunction(cd, i) {
  document.getElementById("showCD").innerHTML =
  "Artist: " +
  cd[i].getElementsByTagName("ARTIST")[0].childNodes[0].nodeValue +
  "<br>Title: " +
  cd[i].getElementsByTagName("TITLE")[0].childNodes[0].nodeValue +
  "<br>Year: " + 
  cd[i].getElementsByTagName("YEAR")[0].childNodes[0].nodeValue;
}