Job Hunting

Now that I've graduated from VCU, it's time to find a job. My wife and I started this year with plans to move out of state, but things came up and we've decided to stay in the area. That decision came a little too late, and I passed up on a couple of really good opportunities. I currently have a few prospects.

If anyone hears of any openings for an Application Developer/System Engineer, send the info my way.

Quake Tracker using Google Maps API v3 and XML/Atom feed

http://www.ipreferjim.com/maps/quakes.html

For this, I used the following:

• Google Maps API v3 (http://code.google.com/apis/maps/documentation/v3/)
• jQuery v1.3.2 (http://jquery.com/)

First, you will need to include the google maps api in your header:

<script src="http://maps.google.com/maps/api/js?sensor=true" type="text/javascript">

This line of code is slightly different from the v2 API because an API key isn't needed. This will probably change in the near future. It is also necessary to load jQuery, which can be done by downloading it from the above link, or loading it via Google's AJAX API.

When the document is ready:

   1:  // init map

   2:  var map;

   3:  $(document).ready(function(){

   4:    var latlng = new google.maps.LatLng(35.6802, -121.1165);

   5:    var myOptions = {

   6:       zoom: 3,

   7:      center: latlng,

   8:      mapTypeControl: true,

   9:      mapTypeControlOptions: {style: google.maps.MapTypeControlStyle.DROPDOWN_MENU},

  10:      navigationControl: true,

  11:      navigationControlOptions: {style: google.maps.NavigationControlStyle.SMALL},

  12:      mapTypeId: google.maps.MapTypeId.SATELLITE

  13:      };

  14:   

  15:    map = new google.maps.Map(document.getElementById("map"), myOptions);

  16:   

  17:  });

When the map is ready:

   1:  // SEE : http://www.xml.com/pub/a/2007/10/10/jquery-and-xml.html

   2:   

   3:  $('#map').ready(function(){

   4:    $.ajax({

   5:      type: "GET",

   6:      url: "getxml.php?q=http://www.earthquake.usgs.gov/eqcenter/catalogs/7day-M2.5.xml",

   7:      dataType: "xml",

   8:      success: function(xml){

   9:              $(xml).find('entry').each(function(){

  10:                  // Retrieve all needed values from XML

  11:                  var title = $(this).find('title').text();

  12:                  var updated = $(this).find('updated').text();

  13:                  var link = $(this).find('link').text();

  14:                  var summary = $(this).find('summary').text();

  15:                  var coord = $(this).find('georss\\:point').eq(0).text();

  16:                  if(!coord){var coord = $(this).find('point').text();};

  17:                  var points = coord.split(' ');

  18:                  var latitude = parseFloat(points[0]);

  19:                  var longitude = parseFloat(points[1]);    

  20:                  var elev = $(this).find('georss\\:elev').eq(0).text();

  21:                  if(!elev){var elev = $(this).find('elev').text();};

  22:                  var htmlString = "<b>" + title + "</b>" + "<p>" + summary + "<br>";

  23:                  // create a marker

  24:                  var myLatlng = new google.maps.LatLng(latitude,longitude);

  25:                      var marker = new google.maps.Marker(

  26:                      {

  27:                          position: myLatlng,

  28:                          map: map,

  29:                          title: title

  30:                      });

  31:                  

  32:                      addMarkerBubble(marker, map, htmlString);

  33:                      // Show output below map

  34:                      $('<li></li>')

  35:                          .html(title + ' (updated: ' + updated + ') at ' + points[0] + ', ' + points[1])

  36:                          .appendTo('#output');

  37:              });// end each

  38:          }

  39:      }); // end $.ajax

  40:  });// end function

  41:   

  42:  function addMarkerBubble(marker, map, message){    

  43:      // set balloon

  44:      var infowindow = new google.maps.InfoWindow(

  45:      {

  46:            content: message,

  47:        size: new google.maps.Size(400,200)

  48:      });        

  49:      

  50:      // add listener to marker

  51:      google.maps.event.addListener(marker, 'click' ,function(){

  52:          infowindow.open(map,marker);

  53:      });

  54:  };

Explanations:

First of all, I create a global variable called map, so I can use it in each function.

Then, when the document is ready, I get a geographic coordinate which Google Maps builds from maps.LatLng. This coordinate is in California, because I know there are quakes there.

Next, I've set a number of options (lines 6-12) for the map including:

• zoom level
• map center
• a control to allow user to change the look of the map
• a control to allow user to change zoom
• default map type of "SATELLITE", which shows tectonic regions

The Google Maps API v3 makes it very easy to supply these options to the Map constuctor, as you can see on line 15 of the first code snippet. The map is loaded into the DOM object supplied as the first parameter in the constructor.

The next snippet is the AJAX call to retrieve the feed and build the markers and info windows when the GET succeeds.

Inside the function call, I've used jQuery's simplified DOM access for the returned XML. On line 9 of this snippet, I find each 'entry' node and then iterate over each of these nodes to find the text of each node value.

On lines 15-16 and 20-21, I check the variables because some browsers properly process namespaced nodes and some don't. This simple check allows the application to display properly in Chrome, Safari, Firefox, and Internet Explorer.

Next, I create a marker on the map at the given coordinate and give it a title (tooltip).

On line 32, I call the function 'addMarkerBubble' to create an info window and add the event to the map. After this, I add the title and updated date to a div element below the map.

JavaScript & CSS Modal Loading DIV

Things I've used in this:

• Prototype Javascript (http://prototypejs.org/)
• Loading image (http://www.ajaxload.info/)
• Script & CSS

What I do here is build a DIV element and show it on the page while Prototype's Ajax Request object is loading. Then, when the Request is finished, the DIV is removed from the document.

Here is the script necessary to make a request and build/show/remove the DIV.

   1:  /** Main.js

   2:   * @author Jim Schubert

   3:   * (c) 2009

   4:   */

   5:   

   6:  function showContent(file){

   7:      var content = new Ajax.Request(file,

   8:          {

   9:              method:'get',

  10:              onLoading: showLoading(),

  11:              onSuccess: function(request)

  12:              {

  13:                  var contentDIV = document.getElementById('content');

  14:                  contentDIV.innerHTML = "";

  15:                  contentDIV.innerHTML = request.responseText;    

  16:                  

  17:                  closeLoading();                        

  18:              },

  19:              onFailure: function(){ alert('Cannot process your request.');}

  20:              // onComplete: closeLoading()

  21:          });

  22:  };

  23:   

  24:  function onImgError(source) {

  25:    source.src = "img/img_error.png";

  26:    // disable onerror to prevent endless loop

  27:    source.onerror = "";

  28:    return true;

  29:  };        

  30:   

  31:  function showLoading() {

  32:      // create div element

  33:      var overlayDIV = document.createElement('div');

  34:      var loadingDIV = document.createElement('div');

  35:      overlayDIV.setAttribute('id', 'overlay');

  36:      overlayDIV.setAttribute('class', 'overlay');

  37:      overlayDIV.style.visibility = 'visible';

  38:      

  39:      loadingDIV.setAttribute('id', 'loading');

  40:      loadingDIV.setAttribute('class', 'modalPopup');

  41:      loadingDIV.innerHTML = '<center><img src="img/ajax-loader.gif"><br>Loading...</center>';

  42:          

  43:      overlayDIV.appendChild(loadingDIV);

  44:      var content = document.getElementById('bodyDocument');

  45:      if (content) {

  46:          content.appendChild(overlayDIV);

  47:          var overlay = document.getElementById('overlay');

  48:          if (overlay) {

  49:              overlay.style.visibility = 'visible';

  50:              overlay.style.height = '100%';

  51:          }

  52:      }

  53:      

  54:      return true;

  55:  };

  56:   

  57:  function closeLoading(){

  58:      var overlayDIV = document.getElementById('overlay');

  59:      var loadingDIV = document.getElementById('loading');

  60:      

  61:      if (overlayDIV) {

  62:          if (loadingDIV) {

  63:              overlayDIV.removeChild(loadingDIV);

  64:              document.getElementById('bodyDocument').removeChild(overlayDIV);

  65:          }

  66:          // else {alert("can't find loadingDIV")}

  67:      }

  68:      // else{ alert("Can't find overlay.");}

  69:      

  70:      return true;

  71:  };

Here is the stylesheet needed to make the dialog "modal".

   1:  .overlay {

   2:      visibility: hidden;

   3:      position: absolute;

   4:      left: 0px;

   5:      top: 0px;

   6:      width:100%;

   7:      height:100%;

   8:      text-align:center;

   9:      z-index: 1000;    

  10:      filter:alpha(opacity=70) !important;

  11:      opacity:0.8 !important;

  12:      elevation:above !important;

  13:      /* background-color:Gray !important; */

  14:      background-image: url(../img/overlay.png);

  15:  }

  16:   

  17:  .modalPopup 

  18:  {

  19:      display: block;

  20:      margin-left: auto;

  21:      margin-right: auto;    

  22:      width:180px;

  23:      margin: 100px auto;

  24:      background-color:#F1F1F1 !important;

  25:      border:1px solid #000;

  26:      padding:15px;

  27:      text-align:center;

  28:      elevation:above !important;

  29:  }

In order to use this code, you'll have to give your body tag an id of 'bodyDocument', and the div tag to receive your ajax request should be called 'content'.
I've also included an image error detecting script, which replaces broken images with a default image. Unfortunately, if you're trying to produce 100% compliant HTML documents, this won't be compliant unless you're using HTML5. In order to use this, you'll have to do something like <img src='asdf.gif' onerror='javascript:onImgError(this)' alt='image'>
I've left some code commented out, which will help in debugging your efforts. And, in the stylesheet, you have the option of using a flat background instead of a PNG with transparency.

Example Ruby code

I decided to do some of those Facebook puzzles in Ruby. I won't post everything I do, because I would consider that cheating (after all, you can win prizes!).

However, considering this is a very simple script, and I'm doing it more for learning Ruby than to enter into Facebook's puzzles, I will post this one.

This is the first puzzle, called Hoppity Hop:

private
@file_exists = false
def get_integer(filename)
    if File::exists?(filename)
        file = File.open(filename) 
        line = file.gets.strip!
        file.close
        @file_exists = true
        return line.to_i
    else
        @file_exists = false
        return 0 #zero files present
    end
end

def get_string(num)
    if(num%3 == 0 && num%5 == 0)
        print "Hop\n"
    elsif num%3 == 0
        print "Hoppity\n"
    elsif num%5 == 0
        print "Hophop\n"
    else
        return #nothing
    end    
end

def hip_hop(arg)
    num = get_integer(arg)
    if(num > 0 && @file_exists)        
        for i in 1..num.to_i
            get_string(i)
        end
    else
        puts "File not found"
    end
end

public

arg = ARGV[0].to_s # this is the name of the file
if(/\D/ =~ arg)
    puts "Please enter a positive integer as the filename."
else
    unless arg == nil
        hip_hop(arg)
    end
end

Ruby on Rails, Aptana Studio

This weekend, I decided to give Ruby on Rails a go, considering I just finished school and I'll have plenty of free time to explore.

I downloaded Aptana Studio and installed Ruby, Rails, PHP, and a few extra ruby gems for fun. Then, I went over to the Rails Guide to follow along and do some learnin'. At the end of the guide, I ran the completed blog application and received errors. A little googling helped me find the solution.

Apparently, Aptana doesn't install the latest build of gems from its repositories, and the guide was written for the newest version.

As noodlygod writes on the forum linked above:

Hello, I just thought I'd post something as I had the same problem on Windows.

I tried running the command "gem install rails --source http://gem.rubyonrails.org" but I received the error: "actionpack requires rack (>= 0.9.0, runtime)"

So I ran "gem install rack" which installed something And then "gem install rails --source http://gem.rubyonrails.org" and it installed 2.3.0 just fine.

Based on this post: http://railsforum.com/viewtopic.php?pid=89050 I also changed my rails version in environment.rb to "2.3.0" and renamed "application.rb" to "application_controller.rb" and everything is working. Thanks a bunch for the info!

Useful Serialization Methods of LINQ to SQL objects

I am just going through a project for my senior "Projects in Information Systems" class, commenting most of the complex logic.  I came across these two methods I wrote to serialze LINQ to SQL objects.  They came in pretty handy, so I thought I'd share even though they don't have error-handling.  I'm not too embarrassed. 

The way I used them was pretty ghetto, I was having troubles getting the objects I needed to serialize to be used in a Session object (I thnk it had something to do with an Order_Details table having two foreign keys to the same table, Ledger, for an IN and OUT field).  Anyway, I serialed the object to XML and just stored the whole string into a listBox's value.  I know that's begging for poor performance, and overriding the data validation checks is opening the ASP.NET page up for security issues, but the only people who are going to use this are me and my instructor.  So, it was a quick work around. I could have stored it in a Session Object as a string, but then I would have had to call some funky work around for the listBox.  Anyway, enough about that.

   1:   

   2:          /// <summary>

   3:          /// Serializes a LINQ object to an XML string

   4:          /// </summary>

   5:          /// <typeparam name="T">Type of the Object</typeparam>

   6:          /// <param name="linqObject">The LINQ object to convert</param>

   7:          /// <returns>string</returns>

   8:          public static string SerializeLINQtoXML<T>(T linqObject)

   9:          {

  10:              // see http://msdn.microsoft.com/en-us/library/bb546184.aspx

  11:              DataContractSerializer dcs = new DataContractSerializer(linqObject.GetType());

  12:   

  13:              StringBuilder sb = new StringBuilder();

  14:              XmlWriter writer = XmlWriter.Create(sb);

  15:              dcs.WriteObject(writer, linqObject);

  16:              writer.Close();

  17:   

  18:              return sb.ToString();

  19:          }

  20:   

  21:          /// <summary>

  22:          /// Deserializes an XML string to a LINQ object

  23:          /// </summary>

  24:          /// <typeparam name="T">The type of the LINQ Object</typeparam>

  25:          /// <param name="input">XML input</param>

  26:          /// <returns>Type of the LINQ Object</returns>

  27:          public static T DeserializeLINQfromXML<T>(string input)

  28:          {

  29:              DataContractSerializer dcs = new DataContractSerializer(typeof(T));

  30:   

  31:              TextReader treader = new StringReader(input);

  32:              XmlReader reader = XmlReader.Create(treader);

  33:              T linqObject = (T)dcs.ReadObject(reader, true);

  34:              reader.Close();

  35:   

  36:              return linqObject;

  37:          }

  38:   

Storing Generics in ASP.NET Profile object

Sometimes, I'll come across a problem that I research for an hour or two. When I find the solution, I think "Wow, that should have been the first thing I tried!"

This is one of those occasions. 

I decided to use the ASP.NET profile instead of Session objects to store a list of products.  So, in web.config, I tried a number of "work-arounds" that I found online, including:

   1:  <profile>

   2:  ...

   3:        <properties>

   4:          <add name="RecentlyViewed" allowAnonymous="false" type="System.Collections.Generic.List`1[Model.Product]" serializeAs="Xml"/>

   5:        </properties>

   6:  </profile>

The problem I was having, and it seems a lot of people are having, is that System.Collections.Generic.List`1[Model.Product] throws an error. For some people, it seems to work. Well, I tried changing the lt and gt in the generic list so the XML would parse it as it is written in the code-behind. That didnt work.

The solution: Create a class which inherits from List<Model.Product>

For instance:

   1:  using System;

   2:  using System.Collections.Generic;

   3:   

   4:  namespace Model

   5:  {

   6:      /// <summary>

   7:      /// This class wraps the Generic List into a class to serialize in Profile provider

   8:      /// </summary>

   9:      [Serializable]

  10:      public class RecentlyViewed : List<Model.Product>

  11:      {

  12:          public RecentlyViewed()

  13:          {

  14:          }

  15:      }

  16:  }

This works beautifully! Now, in web.config, you can do the following:

   1:  <profile>

   2:  ...

   3:        <properties>

   4:          <add name="RecentlyViewed" allowAnonymous="false" type="Model.RecentlyViewed" serializeAs="Xml"/>

   5:        </properties>

   6:  </profile>

Displaying multiple fields in a Dropdownlist's DataTextField

I've encountered this problem on occasion, where I want to display more than one field in a dropdownlist's DataTextField property.  In the past, I've overcome this problem by rewriting a SQL statement, or adding another column in the database itself to accomodate my needs.

In one of my classes (INFO 465: Projects in Information Systems @ VCU), we're working from a database which we're not allowed to change.  The reason we can't change it is because the instructor uses the same database for his examples.  I could just write another method into my business logic layer, but it would get cluttered pretty quickly.

So, I decided to make use of LINQ and found the following solution:

   1:  ddlUsers.DataSource = BLL.Employee.GetEmployees()

   2:                  .Select(be => 

   3:                      new { 

   4:                          ID = be.Id, 

   5:                          FullName = String.Format("{0}{1}{2}", 

   6:                                      be.LastName,

   7:                                      (!string.IsNullOrEmpty(be.FirstName) ? ", " : string.Empty),

   8:                                      be.FirstName)

   9:                          }).AsEnumerable();

This takes the List of Business Entity objects and uses the LINQ select statement to generate an implicit/anonymous object from that. The only downfall to this method is that the new object only has local scope. But, since I'm only using this in a dropdown, it's a pretty nifty trick.

T-SQL Multi-Table Delete

I was trying to run a DELETE query on multiple tables and I kept getting this error: The DELETE statement conflicted with the REFERENCE constraint

I'm not that great with SQL, but I can get by.  DELETEs have always been somethng that have given me trouble.  So, I thought I'd share this simple fix.

DELETE FROM PRODUCT
FROM BOOK
WHERE BOOK.ID = PRODUCT.BOOK_ID
AND BOOK.ID = @BOOK_ID

You just have to make sure you put the table with the FK as the first table in the query.

I guess I should have paid a little more attention in Database class.  We learned Oracle, which is different from Microsoft's SQL in many ways.