Showing posts with label HTML. Show all posts
Showing posts with label HTML. Show all posts

Saturday, March 17, 2012

Yet Another Countdown Timer Application built using .HTA (Windows HTml Applications)

image

Discussion:

The time until something is due is always important. There are a lot of countdown timers which are available. There are a lot of interesting ways to implement a countdown timer. In restricted IT environments, where installing applications is frowned upon, one approach to creating a lightweight application is using HTML Applications (HTA).  The following example shows how to use an HTA to build a standalone countdown timer which is displayed as a window.

Several techniques are used to make this countdown timer work. First, the name of the file is parsed to determine the target date and time. This way, the remaining time can be set by renaming the file. Next, javascript is used to rewrite a portion of the document by assigning a value to the ‘innerHTML’  of  div element. Then, the countdown function is called once when the body of the document is loaded. However, once the function is called, the last thing it does is reschedule itself to run again in 1 second. Finally, this file, which looks like an HTML file is saved as with the extension HTA.

Code Example:

<html>
<head>
	<TITLE>Countdown Timer</TITLE>
	<HTA:APPLICATION 
		ID="oMyApp" 
		APPLICATIONNAME="CountDownTimer" 
		BORDER="yes"
		CAPTION="yes"
		SHOWINTASKBAR="yes"
		SINGLEINSTANCE="yes"
		SYSMENU="yes"
		WINDOWSTATE="normal"
		MAXIMIZEBUTTON="no">
    <script>
		// set the window size and place it on the screen in the upper right hand corner
		var windowWidth = 600
		var windowHeight = 150
		window.resizeTo(600,150);  // Can only be done in HTA
		//half the screen height minus half the new window height (plus title and status bars).
		iMyHeight = (window.screen.height/4) - (windowHeight/2 + 50)/2;
        window.moveTo(window.screen.width-windowWidth-5,5);
    </script>
	<style type="text/css">
		body {
			background-color: green;
			color: black; 
			text-align: center; 
			font-family: arial; 
			font-weight: bold; 
			font-size: 20px;
			font-variant: small-caps;
			border: medium double rgb(0,255,15);
			width:100%;
			overflow: hidden;
			filter:progid:DXImageTransform.Microsoft.Gradient(endColorstr='#00C000',
						startColorstr='#00FFFF', gradientType='0'); 			
			}
	</style>
</head>
<body>
	<!-- Define a division for displaying the countdown message -->
	<div id="countdown" ></div>
	<!-- Define the actions to take when the body loads -->
	<script>
	// parse the filename to get the target date and time
	var filename = String(window.location)              // get filename
	var iSubStrEnd = filename.lastIndexOf('.')       // get point in string where the date data may end
	var iSubStrStart = filename.lastIndexOf('.',iSubStrEnd-1) // get point in string where the date data may start
	if ((iSubStrEnd>0)&&(iSubStrStart>0)&&(iSubStrStart<iSubStrEnd)) {
		// get the date string from the file name
		endDateTime = filename.slice(iSubStrStart+1,iSubStrEnd)
		}
	else {
		// enter the stop date here that will be used if the name is not formatted correctly
		// format for this string is YYYY,MM,DD,HH,MM,SS
		endDateTime = '2015,01,01,0,0,0'
		}
		
	// parse the date
	var params = endDateTime.split(',')
	lyear  = parseInt(params[0])
	lmonth = parseInt(params[1])
	lday   = parseInt(params[2])
	// call the countdown function which will hook itself into a timer and
	//     continue to run every second.
	countdown(lyear,lmonth,lday,params[3],params[4],params[5])	

	//-------------------------------------------------------
	function countdown(yr,m,d,hh,mm,ss){
		var montharray=new Array("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec")
		hh = ("00"+hh).slice(-2);
		mm = ("00"+mm).slice(-2); //if (mm<10) mm = "0"+(mm+1);
		ss = ("00"+ss).slice(-2); //if (ss<10) ss = "0"+ss;
		theyear=yr; themonth=m; theday=d;
		thehh=parseInt(hh); themm=parseInt(mm); thess=parseInt(ss);
		var today=new Date();
		var todayy=today.getFullYear();
		var todaym=today.getMonth()+1;
		var todayd=today.getDate();
		var todayh=today.getHours();
		var todaymin=today.getMinutes();
		var todaysec=today.getSeconds();
		var todaystring=montharray[todaym]+" "+todayd+", "+todayy+" "+todayh+":"+todaymin+":"+todaysec
		futurestring   =montharray[m-1]   +" "+d     +", "+yr    +" "+hh    +":"+mm      +":"+ss
		var dd    = Date.parse(futurestring)-Date.parse(todaystring);
		var dday  = Math.floor(dd/(60*60*1000*24)*1);
		var dhour = Math.floor((dd%(60*60*1000*24))/(60*60*1000)*1);
		var dmin  = Math.floor(((dd%(60*60*1000*24))%(60*60*1000))/(60*1000)*1);
		var dsec  = Math.floor((((dd%(60*60*1000*24))%(60*60*1000))%(60*1000))/1000*1);
		if(dday<=0&&dhour<=0&&dmin<=0&&dsec<=0){
			// put text in the "countdown" division to show the countdown expired
			document.getElementById("countdown").innerHTML = "<br> Time has run out! <br>";
			return;
			}
		else {
			dhour = ("00"+dhour).slice(-2);
			dmin  = ("00"+dmin).slice(-2);
			dsec  = ("00"+dsec).slice(-2);
			// format the delta time and put in the countdown division to display
			document.getElementById("countdown").innerHTML = 
				"<br> Times out in "+dday+ 
				" days, "+dhour+" hours, "+dmin+" minutes, and "+dsec+
				" seconds  <br>";
			}
		// trigger this routine to run again in 1 second
		setTimeout("countdown(theyear,themonth,theday,thehh,themm,thess)",1000);
		} 

	</script>
	</body>
</html>

 

TEsting Environment:

  • IE9
  • Win7
This work is licensed under a Creative Commons Attribution By license.

Friday, February 24, 2012

Using HTML to View Large Sets of Plots - An Example in Python



This example doesn't work because of Blogger limitations. However if you run the example you will be able to select graphs in the generated HTML page.

Problem Statement

You have a program which generates lots of similar plots that end users would like to compare and explore. The end users may not be able to install any code. You can't setup a web server to nagivate the data set. You can not install any new programs on their window's desktop. How to you provide a solution?

Discussion

You can assume that any modern computer at least has a copy of Firefox, Safari, or Explorer. Since there browers support javascript (except in the worst case security settings), you can build a very lightweight data viewer using a few simple methods. The most important design decisions when generating the plots is to name the plots so they are easy to recreate from selections an end user might make.

Example

The following snippet of Python code generates 9 graphs that have random numbers plotted on two axes using different colors and markers. There are three choices of colors and three choices of markers. After generating the plots and saving them, the script creates an HTML file which simplies the navigation of the images. A user can open the HTML page and select the graph by changing the form selections at the top of the page.

There are a couple of key concepts that help make this work:
  • The plot names can be created from selections using javascript. For example, in this example there are three colors and three different markers. All of the plot file names are formed by concatenating the color and marker description to form a plot name.
  • When a user changes their choice of color or marker a javascript function rebuilds the plot file name and causes the browser to reload the image by change the img source.
  • The python script uses templates to set up the bulk of the HTML page, then substitutes in specific options for the user after the plots have been generated. 

import pylab as plt
from random import random
from string import Template

colors  = {'Red_Plot':'r',
           'Blue_Plot':'b',
           'Green_Plot':'g',
           }
markers = {'Circle_Plot':'o',
           'Square_Plot':'s',
           'Diamond_Plot':'d',
           } 

plt.figure()
for c_key in colors.keys():
    for m_key in markers.keys():
        plt.clf()
        plot_name = c_key + ',' + m_key + '.png'
        x = [random() for i in range(0,100)]
        y = [random() for i in range(0,100)]
        color = colors[c_key]
        marker = markers[m_key]
        plt.plot(x,y,color+marker,markersize=15)
        plt.savefig(plot_name)
        
HTML_template = Template('''<head>
   <script language="JavaScript"><!--
      function sel_plot() {
         // only do this if the brower supports images
         if(document.images) {
            // get plot color name
            var e=document.getElementById("color_name");
            var c_name = e.options[e.selectedIndex].text;
            // get plot marker name
            var e=document.getElementById("marker_name");
            var m_name = e.options[e.selectedIndex].text; // create the filename
            // build the filename from these selections
            var plot_filename = c_name + "," + m_name + ".png";
            // cause the correct plot to be loaded
            document["plot"].src = plot_filename;
            }
         }
      // select the plot to display initially after loading document
      window.onload = function() { sel_plot() };
      // silence errors
      window.onerr = null;
   </script>
</head>
<body>
   <center>
      <form name="Plot Select Form" id="plot_select_form">
         <select id="color_name" size="3"
            onchange="sel_plot()">
            $color_options
         </select>
         <select id="marker_name" size="3"
            onchange="sel_plot()">
            $marker_options
         </select>
      </form>
      <img name="plot" src="dummy.png" height="200"
         width="500">
   </center>
</body>
''')
        

# build the option strings
def build_options(opt_dict):
    s = ''
    for i,key in enumerate(opt_dict.keys()):
        if i==1:
            s += '<option selected>'
        else:
            s += '<option>'
        s += key
        s += '</option>\n'
    return s    

color_options = build_options(colors)
marker_options = build_options(markers)

# build the HTML page        
HTML = HTML_template.substitute(color_options=color_options,
                     marker_options=marker_options)
    

# write the HTML page
f = open('example.html','wb')
f.write(HTML)
f.close()

Test Configuration

  • PythonXY 2.7.2.1
  • IE 9


This work is licensed under a Creative Commons Attribution By license.