16-1.txt

Javascript语言开发经典教程开发

<FORM NAME="everything">  <!-- A one-of-everything HTML form... -->
 <TABLE BORDER CELLPADDING=5>   <!-- ...in a big HTML table. -->
   <TR>
     <TD>Username:<BR>[1]<INPUT TYPE=text NAME="username" SIZE=15></TD>
     <TD>Password:<BR>[2]<INPUT TYPE=password NAME="password" SIZE=15></TD>
     <TD ROWSPAN=4>Input Events[3]<BR>
       <TEXTAREA NAME="textarea" ROWS=20 COLS=28></TEXTAREA></TD>
     <TD ROWSPAN=4 ALIGN=center VALIGN=center>
       [9]<INPUT TYPE=button VALUE="Clear" NAME="clearbutton"><BR>
       [10]<INPUT TYPE=submit NAME="submitbutton" VALUE="Submit"><BR>
       [11]<INPUT TYPE=reset NAME="resetbutton" VALUE="Reset"></TD></TR>
   <TR>
     <TD COLSPAN=2>Filename: [4]<INPUT TYPE=file NAME="file" SIZE=15></TD></TR>
   <TR>
     <TD>My Computer Peripherals:<BR>
       [5]<INPUT TYPE=checkbox NAME="peripherals" VALUE="modem">28.8K Modem<BR>
       [5]<INPUT TYPE=checkbox NAME="peripherals" VALUE="printer">Printer<BR>
       [5]<INPUT TYPE=checkbox NAME="peripherals" VALUE="tape">Tape Backup</TD>
     <TD>My Web Browser:<BR>
       [6]<INPUT TYPE=radio NAME="browser" VALUE="nn">Netscape Navigator<BR>
       [6]<INPUT TYPE=radio NAME="browser" VALUE="ie">Internet Explorer<BR>
       [6]<INPUT TYPE=radio NAME="browser" VALUE="other">Other</TD></TR>
   <TR>
     <TD>My Hobbies:[7]<BR>
       <SELECT multiple NAME="hobbies" SIZE=4>
         <OPTION VALUE="programming">Hacking JavaScript
         <OPTION VALUE="surfing">Surfing the Web
         <OPTION VALUE="caffeine">Drinking Coffee
         <OPTION VALUE="annoying">Annoying my Friends
       </SELECT></TD>
     <TD align=center valign=center>My Favorite Color:<BR>[8]
       <SELECT NAME="color">
         <OPTION VALUE="red">Red        <OPTION VALUE="green">Green
         <OPTION VALUE="blue">Blue      <OPTION VALUE="white">White
         <OPTION VALUE="violet">Violet  <OPTION VALUE="peach">Peach
       </SELECT></TD></TR>
 </TABLE>
</FORM>

<DIV ALIGN=center>        <!-- Another table--the key to the one above. -->
  <TABLE BORDER=4 BGCOLOR=pink CELLSPACING=1 CELLPADDING=4>
    <TR>
      <TD ALIGN=center><B>Form Elements</B></TD>
      <TD>[1] Text</TD>  <TD>[2] Password</TD>  <TD>[3] Textarea</TD>
      <TD>[4] FileUpload</TD> <TD>[5] Checkbox</TD></TR>
    <TR>
      <TD>[6] Radio</TD>  <TD>[7] Select (list)</TD>
      <TD>[8] Select (menu)</TD>  <TD>[9] Button</TD>
      <TD>[10] Submit</TD>  <TD>[11] Reset</TD></TR>
  </TABLE>
</DIV>

<SCRIPT LANGUAGE="JavaScript1.1">
// This generic function appends details of an event to the big Textarea
// element in the form above. It will be called from various event handlers.
function report(element, event) 
{
    var t = element.form.textarea;
    var elmtname = element.name;
    if ((element.type == "select-one") || (element.type == "select-multiple")){
        value = " ";
        for(var i = 0; i < element.options.length; i++)
            if (element.options[i].selected) 
                value += element.options[i].value + " ";
    }
    else if (element.type == "textarea") value = "...";
    else value = element.value;
    var msg = event + ": " + elmtname + ' (' + value + ')\n';
    t.value = t.value + msg;
}

// This function adds a bunch of event handlers to every element in a form.
// It doesn't bother checking to see if the element supports the event handler,
// it just adds them all. Note that the event handlers call report() above.
function addhandlers(f)
{
    var click_handler = new Function("report(this, 'Click')");
    var change_handler = new Function("report(this, 'Change')");
    var focus_handler = new Function("report(this, 'Focus')");
    var blur_handler = new Function("report(this, 'Blur')");
    var select_handler = new Function("report(this, 'Select')");
	
    for(var i = 0; i < f.elements.length; i++) {
        var e = f.elements[i];
        e.onclick = click_handler;
        e.onchange = change_handler;
        e.onfocus = focus_handler;
        e.onblur = blur_handler;
        e.onselect = select_handler;
    }

    // Special case handlers for the buttons:
    f.clearbutton.onclick = 
        new Function("this.form.textarea.value=''; report(this, 'Click');");
    f.submitbutton.onclick = 
        new Function("report(this, 'Click'); return false");
    f.resetbutton.onclick = 
        new Function("this.form.reset(); report(this, 'Click'); return false");
}
// Activate our form by adding all possible event handlers!
addhandlers(document.everything);
</SCRIPT>