Ajax + php + xml: Online Exam Q & A system

Last Update:2017-01-13 Source: Internet

Author: User

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<Html>
<Head>
<Title> Ajax application </title>
<Script language = "JavaScript" type = "text/javascript" src = "ajax. js"> </script>
<Style type = "text/css">
<! -- CSS style sheets are used to define the display appearance of a page and separate content from display.
# Answershow {border: # E2FAFA; color: #000099; font-size: 12px ;}
# Main {visibility: hidden ;}
# Begin {
Visibility: visible;
Position: absolute;
Left: 135px;
Top: 103px;
Width: 37px;
Height: 16px;
Z-index: 1;
}
-->
</Style>
</Head>
<Body>
<Div id = "begin"> <input type = "button" id = "startq" value = "start"> </div>
<H1> simple test system <Div id = "main">
<P> <B> answer: </B> <input type = "text" id = "answer">
<Input type = "button" value = "Submit" id = "submit">
<Br> <B> Tip: </B> <span id = "answershow"> </span>
</Div>
<Script language = "JavaScript" type = "text/javascript" src = "manage. js"> </script>
</Body>
</Html>

Ajax. js file

Var ajaxreq = false, ajaxCallback;
Function ajaxRequest (filename ){
Try {
Ajaxreq = new XMLHttpRequest ();
} Catch (error ){
Try {
Ajaxreq = new ActiveXObject ("Microsoft. XMLHTTP ");
} Catch (error ){
Return false;
}
}
Ajaxreq. open ("GET", filename );
Ajaxreq. onreadystatechange = ajaxResponse;
Ajaxreq. send (null );
}
Function ajaxResponse (){
If (ajaxreq. readyState! = 4) return;
If (ajaxreq. status = 200 ){
If (ajaxCallback) ajaxCallback ();
} Else alert ("Request failed:" + ajaxreq. statusText );
Return true;
}
It is easy to create xmlhttp. The best method to create xmlhttp is more practical and sound.

Mange. js file,

Var qn = 0, questions, right = 0;
Function getQuestions () {// getElementById is used to locate the page element to be operated
Document. getElementById ("main"). style. visibility = "visible ";
Document. getElementById ("begin"). style. visibility = "hidden ";
Document. getElementById ("answer"). focus ();
Obj = document. getElementById ("question ");
Obj. firstChild. nodeValue = "Loading .....";
AjaxCallback = nextQuestion;
AjaxRequest ("questions. xml"); // XML text loading from the server
}
Function nextQuestion () {// display the next question
Questions = ajaxreq. responseXML. getElementsByTagName ("ask ");
Obj = document. getElementById ("question ");
If (qn <questions. length ){
Q = questions [qn]. firstChild. nodeValue;
Obj. firstChild. nodeValue = q;
} Else {// score when the user answers the question
Var anobj = document. getElementById ("answershow ");
Anobj. innerHTML = "your score is:" + right/questions. length * 100;
   }
}
Function checkAnswer () {// instantly checks user answers
Answers = ajaxreq. responseXML. getElementsByTagName ("key ");
A = answers [qn]. firstChild. nodeValue;
Answerfield = document. getElementById ("answer ");
If (answerfield. value = "") {var anobj = document. getElementById ("answershow"); // prompt when the user does not answer
Var anobj = document. getElementById ("answershow ");
Anobj. innerHTML = "Sorry, you have not answered ";
Answerfield. focus ();
Return ;}
Else if (a. toLowerCase () = (answerfield. value). toLowerCase () {// prompt when the user is correct
Right ++;
Var anobj = document. getElementById ("answershow ");
Anobj. innerHTML = "correct answer! ";
Answerfield. focus ();
   }
Else {
Var anobj = document. getElementById ("answershow"); // The prompt displayed when the user makes an error
Anobj. innerHTML = "incorrect answer. Answer:" +;
Answerfield. focus ();
    }
Qn = qn + 1;
Answerfield. value = "";
NextQuestion ();
}
// The following action buttons create Event Processing
Obj = document. getElementById ("startq ");
Obj. onclick = getQuestions;
Ans = document. getElementById ("submit ");
Ans. onclick = checkAnswer;
This file is an analysis node and determines whether the answer is correct.

Questions. php

<? Php
$ Link = mysql_connect ("localhost", "root ","");
Mysql_select_db ("quiz", $ link );
Mysql_query ("set names gb2312 ");
$ SQL = mysql_query ("select * from questions ");
Echo "<? Xml version = '1. 0' encoding = 'gb2312 '?> <Questions> ";

While ($ info = mysql_fetch_array ($ SQL )){
Echo "<ask>". $ info [question]. "</ask> <key>". $ info [answer]. "</key> ";
};
Echo "</questions> ";
?>

Questions. xml

<? Xml version = "1.0" encoding = "gb2312"?>
<Questions>
<Ask> which of the following is more efficient than the traditional web development mode and Ajax development mode? </Ask>
<Key> Ajax </key>
<Ask> What are the core objects of Ajax technology? </Ask>
<Key> XMLHttpResponse </key>
<Ask> what methods does Ajax use to locate the elements you need to operate on? </Ask>
<Key> getElementById </key>
<Ask> what technology does Ajax use to define display? </Ask>
<Key> CSS </key>
<Ask> which attribute of XMLHttpResponse stores the server's browser response (as an xml document )? </Ask>
<Key> responseXML </key>
</Questions>

That's easy. Let's take a look at this.

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