Fiction.js (or making fun of javascript library names)

JavaScript libraries have some pretty awesome names. Unless you want to know what that library actually does that is. But hey, these names are great for inspiring fiction. As many of you know, I write fiction on the side. So here comes some fiction.js your way:

He straightened his backbone.js and tightened his angular.js jaw. Then he ate a banana.js while wearing a Bazinga.js shirt. He rubbed the handlbars.js of his mustache.js. His shotgun.js was ready.js. He looked at to the badass.js woman at his right.js. Jasmine.js had long.js auburn hair and a glow.js to her face. Her figure.js was a sight to behold.js–definitely a knockout.js. She sipped a cappucino.js. Kinetic.js magic.js was her forte.js. That and fire.js. She lifted her free hand.js and an ember.js of light.js illuminated.js her palm.

Evil.js was coming. Raphaël.js and Jasmine.js were ready.js!


Why to use string.format() over concatenation (Real world experience)

So today I was working on reverse engineering some old code. I will strip this down and remove proprietary info but still let you see the bug. This is a post for newbies but experienced coders might get a laugh out of this as well.

Here is the error code:

var contract = CustomerId + ProductGroupId + EndDate.ToString("yy-MM");

Now, imagine these values:

CustomerId = 12345
ProductId = 4
Date = 8/7/2014

A new developer would assume that this would return the following:

12345415-08

They would be wrong. See, CustomerId and ProductGroupId are integers. So they don’t concatenate as strings, they add as integers. The real value is this:

1234915-08

12345 + 4 = 12349. This is math, not string concatenation.

How would a developer resolve this bug? There are two solutions:

  • Use ToString() and concatenation (DO NOT USE!)
  • Use string.Concat() (USE FOR SIMPLE CONCATENATION OR PERFORMANCE!)
  • Use string.Format() (USE FOR CONCATENATION WITH FORMATTING!)

Here is the another interesting fact. I know exactly when this bug was introduced into the system. This code was written by the developer using the first solution. The developer had originally added .ToString() to the end of these objects. The developer didn’t write buggy code. He wrote code that worked.

The code used to look like this:

var contract = CustomerId.ToString() + ProductGroupId.ToString() + EndDate.ToString("yy-MM");

So what happened? If a developer didn’t break this code, who did?

I’ll tell you what happened and who did it. Resharper.

Today, developers aren’t the only ones messing with our code. We use tools that are pretty awesome to do masses of code automation for us. One of these tools is Resharper. Well, Resharper detected the ToString() methods as “Redundant Code.” Oh, in this case, it wasn’t redundant code.

The only reason I found this bug is because I was rewriting this piece of code and had to reconstruct a ContractId and I began reverse engineering this code. I noticed that the first part of the ContractId was the CustomerId up until a few months ago. After that, it seemed to be slightly off. I was able to check source from back then and see the difference and see why this bug started. Sure enough, when resharper cleaned up my redundant code, it removed the ToString() methods.

However, while this is a Resharper bug, let’s not jump so fast to blaming Resharper. I’ll submit a bug to them, but are they really at fault? I say not completely. Why? Because the developer chose to use ToString() and concatenation instead of string.Format(). This was the wrong choice. Always use string.format(). This has been preached by many, but just as many don’t listen.

What would have happened if the developer had followed the best practice to use string.Format() or string.Concat?

var contract = string.Concat(CustomerId, ProductGroupId, EndDate.ToString("yy-MM"));

or

var contract = string.Format("{0}{1}{2}", CustomerId, ProductGroupId, EndDate.ToString("yy-MM");

The bug would never had occurred. With either string.Concat() or string.Format(). In those uses, the ToString() methods really would be redundant. With or without them, the code acts the same.

But surely avoiding a Resharper bug isn’t the only reason to use string.Concat or string.Format()? Of course there are more reasons. This error was due to the ambiguous + operator. Using string.Format() or string.Concat() eliminates such ambiguities. Also, with string.Format(), the developer’s intentions are much more clear. The format decided upon is explicitly included. When I type “{0}{1}{2}”, there is no question about what the intended format is. This is why I chose string.Format() for this piece of code. It is self-documenting and unambiguous.

Conclusion

Best practices are best  practices for a reason. Use them. Using string.Format() is always preferable to string concatenation.

P.S. This old project also could have alerted us to this error if anyone would have bothered to write a Unit Test. But this code was buried deep in a method that itself was hundreds of lines long. Following the 100/10 rule and testing would have alerted us when Resharper introduced this error.


Add sql constraint on null, empty, or whitespace (C# string.IsNullOrWhiteSpace() equivelant)

Here is a User table. We wanted to make the UserName column not be null, empty, or whitespace.

So the constraint I made is this

ALTER TABLE [dbo].[User]  WITH CHECK ADD  CONSTRAINT [UserNameNotEmpty] CHECK  (([UserName]<>'' AND rtrim(ltrim(replace(replace(replace([UserName],char((9)),''),char((13)),''),char((10)),'')))<>''))
[UserName]<>''
Empty is checked first and not allowed.
replace([UserName],char((9)),'')
Replaces any instance a Tab character with an empty string.
replace([UserName],char((10)),'')
Replaces any instance a Carriage Return character with an empty string.
replace([UserName],char((13)),'')
Replaces any instance a Line Feed character with an empty string.
ltrim([UserName])
Left trim. It trims spaces from the left side of the string.
rtrim([UserName])
Right trim. It trims spaces from the right side of the string.

Note: You should know that char(9) is tab, char(10) is line feed, char(13) is carriage return.

Here is a complete User table. (This is a legacy system I inherited and I am fixing inadequacies.)

CREATE TABLE [dbo].[User](
	[UserId] [int] IDENTITY(1,1) NOT NULL,
	[UserName] [varchar](255) NOT NULL,
	[Password] [varchar](255) NOT NULL,
	[Salt] [varchar](255) NOT NULL,
	[FirstName] [varchar](255) NULL,
	[LastName] [varchar](255) NULL,
	[Email] [varchar](255) NULL,
	[Active] [bit] NOT NULL
 CONSTRAINT [PK_User] PRIMARY KEY CLUSTERED 
(
	[UserId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY],
UNIQUE NONCLUSTERED 
(
	[UserName] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
SET ANSI_PADDING OFF
ALTER TABLE [dbo].[User] ADD  CONSTRAINT [DF_User_Active]  DEFAULT ((1)) FOR [Active]
ALTER TABLE [dbo].[User]  WITH CHECK ADD  CONSTRAINT [UserNameNotEmpty] CHECK  (([UserName]<>'' AND rtrim(ltrim(replace(replace(replace([UserName],char((9)),''),char((13)),''),char((10)),'')))<>''))
ALTER TABLE [dbo].[User] CHECK CONSTRAINT [UserNameNotEmpty]

Notice, I don’t check null on the constraint, as NOT NULL is part of the UserName column design.


How to add a progress bar to your blog

Some authors want to add progress bars to their blog. However, most authors are not web designers or developers. So they don’t know how to do this. Well, there is a secret in the html development world. The secret is that “Everything is easy once you know how to do it.” Yes, it is actually pretty easy to add a progress bar. I just added a progress bar to my blog.

Creating a Progress Bar on your Blog

Step 1. Create an HTML Widget for your side bar.

Using your blogging engine (WordPress or Blogger or whatever) create an html widget. In WordPress you would use a Text widget.

Step 2. Paste in the following html code

1st draft of Book 2
<div id="progressbar" style="background-color:black;border-radius:6px;padding:3px;">
    <div style="background-color:#dd6013;width:30%;height:10px;border-radius:4px;"></div>
</div>

It will look like this:

1st draft of Book 2

[Read More . . .]


I broke 2000 points on Stack Overflow

Check out my StackOverflow profile. http://stackoverflow.com/users/375727/rhyous?tab=badges

I broke 2000 points.


Select Option Web Control with Knockout.js and MVVM

<!-- Step 1 - Create the HTML File or the View -->
<!DOCTYPE html>
<html>
<head>
    <!-- Step 2 - Include jquery and knockout -->
    <script type="text/javascript" src="http://code.jquery.com/jquery-latest.pack.js"></script>
    <script type="text/javascript" src="http://knockoutjs.com/downloads/knockout-3.0.0.js"></script>
     
    <!-- Step 3 - Add script to run when page loads -->
    <script type="text/javascript" >
        $(document).ready(function(){
 
 
            <!-- Step 4 - Create a data model -->
            var SelectableListDataModel = function () {
                // Private
                var _self = this;

                // Public
                _self.labels = new Array(); // Should have same count as values
                _self.values = new Array(); // Should have same count as Labels
                _self.defaultValue = 0;
                _self.canSelectMethod = function () { return true; },
                _self.push = function (label, value) {
                    _self.labels.push(label);
                    _self.values.push(value);
                };
            };
 
            <!-- Step 5 - Add an OptionViewModel -->
            var OptionViewModel = function(parent, label, value, canSelectMethod) {
                // private
                var _self = this;
                var _parent = parent;

                // public
                _self.id = ko.observable();
                _self.class = ko.observable();
                _self.label = label ? ko.observable(label) : ko.observable();
                _self.value = value ? ko.observable(value) : ko.observable();
                _self.isSelected = ko.computed(function () {
                    return (_parent && _parent.selectedValue) ? _parent.selectedValue() == _self.value() : false;
                }, _self);
                _self.canSelect = canSelectMethod ? ko.computed(canSelectMethod) : ko.computed(function () { return true; });
            };

            <!-- Step 6 - Add an SelectViewModel -->
            var SelectViewModel = function (selectableListDataModel) {
                // private
                var _self = this;
                var _defaultDataModel = new SelectableListDataModel();
                var _dataModel = selectableListDataModel ? selectableListDataModel : _defaultDataModel;

                // Public
                _self.canSelect = (_dataModel.canSelectMethod)? ko.computed(_dataModel.canSelectMethod) : ko.computed(_defaultDataModel.canSelectMethod);
                _self.list = ko.observableArray();
                _self.selectedValue = _dataModel.defaultValue ? ko.observable(_dataModel.defaultValue) : ko.observable();
                
                if (_dataModel.labels && _dataModel.values) {
                    for (var i = 0; i < _dataModel.labels.length; i++) {
                        _self.list.push(new OptionViewModel(_self, _dataModel.labels[i], _dataModel.values[i], _self.canSelect));
                    }
                }
                
                _self.selectedIndex = ko.computed(function () {
                    var index = 0;
                    var foundIndex = -1;
                    ko.utils.arrayForEach(_self.list(), function (item) {
                        if (_self.selectedValue() == item.value()) {
                            foundIndex = index;
                        }
                        index++;
                    });
                    return foundIndex;
                }, _self);

                _self.selectedText = ko.computed(function () {
               _self.selectedText = ko.computed(function () {
                    var index = _self.selectedIndex();
                    return (_self.list()[index]) ? _self.list()[index].label() : "";
                }, _self);
                }, _self);
                
                _self.clear = function (value) {
                    _self.selectedValue(value ? value : "");
                };
            }
 
            <!-- Step 7 - Create ViewModel for whatever you need -->
            function SurveyAnswerViewModel() {
                var self = this;
                 
                <!-- Step 8 - Create an observable list instance -->
                self.dataModel = new SelectableListDataModel();
                self.dataModel.labels = new Array("Good", "Average", "Poor");
                self.dataModel.values = new Array(10,5,1);
                self.dataModel.selectedValue = 10;
                
                <!-- Step 9 - Create a SelectViewModel instance -->
                self.selectGroup1 = new SelectViewModel(self.dataModel);                       
                 
                <!-- Step 10 - Create a computed value to require a selection before submitting -->
                self.canClick = ko.computed( function() {
                    return self.selectGroup1.selectedValue() != "";
                }, self);
                
                <!-- Step 11 - Make some button methods for this example -->
                self.submitClick = function(){
                    // Do something here
                }
                
                self.resetClick = function(){
                    self.selectGroup1.clear();
                }
            }
            
            <!-- Step 12 - Create a computed value to require a selection before submitting -->   
            ko.applyBindings(new SurveyAnswerViewModel());
        });
    </script>
</head>
<body>
    <!-- Step 13 - Create a drop down select item -->
    <select data-bind="options: selectGroup1.list, optionsText: 'label', optionsValue: 'value', value: selectGroup1.selectedValue"></select>
    <br />
    
    <!-- Step 14 - Add html elements to see other properties -->
    <p data-bind="text: 'Index: ' +  selectGroup1.selectedIndex()"></p>
    <p data-bind="text: 'Value: ' +  selectGroup1.selectedValue()"></p>
    <p data-bind="text: 'Text: ' +  selectGroup1.selectedText()"></p>
     
    <!-- Step 15 - Add a button and bind its to methods -->
    <button type="submit" id="btnSubmit" data-bind="enable: canClick, click: submitClick">Submit</button>
    <button type="reset" id="btnReset" data-bind="enable: canClick, click: resetClick">Reset</button>
 
</body>
</html>

RadioButton web control with Knockout.js and MVVM

Here is an example of a RadioButton control using Knockout and MVVM. Hope this helps anyone looking.

<!-- Step 1 - Create the HTML File or the View -->
<!DOCTYPE html>
<html>
<head>
    <!-- Step 2 - Include jquery and knockout -->
    <script type="text/javascript" src="http://code.jquery.com/jquery-latest.pack.js"></script>
    <script type="text/javascript" src="http://knockoutjs.com/downloads/knockout-3.0.0.js"></script>
     
    <!-- Step 3 - Add script to run when page loads -->
    <script type="text/javascript" >
        $(document).ready(function(){
 
            <!-- Step 4 - Add a RadioButtonModel -->
            var RadioButtonModel = function(parent, inText, inValue, inGroupName, canClickMethod) {
                    // Private
                    var _self = this;
                    var _canClickMethod = (canClickMethod) ? canClickMethod : function() { return true; };
                    var _parent = parent;

                    // Public
                    this.text = ko.observable(inText);
                    this.value = ko.observable(inValue);
                    this.group = ko.observable(inGroupName);
                    this.class = ko.observable();
                    this.isSelected = ko.computed(function() {
                        return (_parent && _parent.selectedValue) ? _parent.selectedValue() == _self.value() : false;
                    }, _self);
                    _self.canClick = ko.computed(function() { return _canClickMethod(); });
                };
                
                
            <!-- Step 5 - Add a RadioButtonViewModel -->
            var RadioButtonViewModel = function (rbLabels, rbValues, group, defaultValue) {
                // Private
                var _self = this;
                var _rbLables = rbLabels;
                var _rbValues = rbValues;
                var _group = group;
                var _defaultValue = defaultValue;                

                // Public
                _self.selectedValue = ko.observable(_defaultValue);
                
                _self.list = ko.observableArray();
                for (var i = 0; i < _rbLables.length; i++) {
                    _self.list.push(new RadioButtonModel(_self, _rbLables[i], _rbValues[i], _group));
                }

                _self.selectedIndex = ko.computed(function () {
                    var i = 0;
                    var foundIndex = -1;
                    ko.utils.arrayForEach(_self.list(), function (item) {
                        if (_self.selectedValue() == item.value()) {
                            foundIndex = i;
                        }
                        i++;
                    });
                    return foundIndex;
                }, _self);

                _self.selectedText = ko.computed(function () {
                    return (_self.list()[_self.selectedIndex()]) ? _self.list()[_self.selectedIndex()].text() : "";
                }, _self);
                
                _self.clear = function(value){
                    _self.selectedValue(value ? value : "");
                }
                
            }
 
            <!-- Step 6 - Create ViewModel for whatever you need -->
            function SurveyAnswerViewModel() {
                var self = this;
                 
                <!-- Step 7 - Create an observable list instance -->
                self.rbGroup1 = new RadioButtonViewModel(new Array("Good", "Average", "Poor"), new Array(10,5,1), "Group1", 10);                           
                 
                <!-- Step 8 - Create a computed value to require a selection before submitting -->
                self.canClick = ko.computed( function() {
                    return self.rbGroup1.selectedValue() != "";
                }, self);
                
                <!-- Step 9 - Make some button methods for this example -->
                self.submitClick = function(){
                    // Do something here
                }
                
                self.resetClick = function(){
                    self.rbGroup1.clear();
                }                 
            }
            
            <!-- Step 10 - Create a computed value to require a selection before submitting -->   
            ko.applyBindings(new SurveyAnswerViewModel());
        });
    </script>
</head>
<body>
    <!-- Step 11 - Create a div containing the html for one radio button and bind to foreach: list -->
    <div data-bind="foreach: rbGroup1.list">
        <div>
            <input type="radio" data-bind="attr: {name: group}, value: value, checked: $root.rbGroup1.selectedValue, checkedValue: value" />
            <span data-bind="text: $index() + '. ' + text()"></span>
            <span data-bind="text: 'Is selected: ' + isSelected()"></span>
        </div>
    </div>
    <br />
    
    <!-- Step 12 - Add html elements to see other properties -->
    <p data-bind="text: rbGroup1.selectedValue"></p>
    <p data-bind="text: rbGroup1.selectedText"></p>
     
    <!-- Step 13 - Add a button and bind its to methods -->
    <button type="submit" id="btnSubmit" data-bind="enable: canClick, click: submitClick">Submit</button>
    <button type="reset" id="btnReset" data-bind="enable: canClick, click: resetClick">Reset</button>
 
</body>
</html>

Using slideToggle with Knockout’s MVVM

I recommend you use the third option: Option 3 – Boolean binding using a custom binding handler called slideToggle

<!-- Step 1a - Create the HTML File or the View -->
<!DOCTYPE html>
<html>
<head>
    <!-- Step 2 - Include jquery and knockout -->
    <script type="text/javascript" src="http://code.jquery.com/jquery-latest.pack.js"></script>
    <script type="text/javascript" src="http://knockoutjs.com/downloads/knockout-3.0.0.js"></script>
     
    <!-- Step 3 - Add script to run when page loads -->
    <script type="text/javascript">
        $(document).ready(function(){
         
            <!-- Step 4 - Create a ViewModel -->           
            function viewModel() {
                _self = this;
                _self.showHideChild = function(viewModel, event) {
                    $(event.currentTarget).children('div').slideToggle()
                };
                _self.showHideNextSibling = function(viewModel, event) {
                    var siblings = $(event.currentTarget).siblings('div');
                    for (var i=0;i<siblings.length;i++) {
                        if (siblings[i].previousElementSibling == event.currentTarget ) {
                            $(siblings[i]).slideToggle();
                        }
                    }                 
                };
                _self.isVisible = ko.observable(false);
                _self.showHide = function() {
                    _self.isVisible(!_self.isVisible());
                }
            };
           
            ko.bindingHandlers.slideToggle = {
                init: function (element, valueAccessor) {
                    var value = valueAccessor();
                    $(element).toggle(ko.utils.unwrapObservable(value));
                },
                update: function (element, valueAccessor) {
                    var value = valueAccessor();
                    var isVisible = element.offsetWidth > 0 && element.offsetHeight > 0;
                    if (ko.utils.unwrapObservable(value) != isVisible) {
                        $(element).slideToggle();
                    }
                }
            };
           
            <!-- Step 5 -  Activates knockout.js bindings -->
          ko.applyBindings(new viewModel());
        });
    </script>
</head>
<!-- Step 4 - Create a HTML Elements with bindings -->
<body style="">
    <div>
        Option 1 - Child div
        <div id="child1" data-bind="click: showHideChild" style="border:2px solid;">
        Click me
            <div id="child2" style="display: none;">
              Now you see me!
            </div>
        </div>
        
        Option 2 - Siblings div
        <div id="sib1" style="border:2px solid;">
            <div id="sib2" data-bind="click: showHideNextSibling" >
            Click me
            </div>
            <div id="sib3" style="display: none;">
            Now you see me!
            </div>
            <div id="sib4">
            You should always see me.
            </div>
        </div>
        Option 3 - Boolean binding using a custom binding handler called slideToggle 
        <div id="bool1" style="border:2px solid;">
            <div id="bool2" data-bind="click: showHide" >
            Click me
            </div>
            <div id="bool3" data-bind="slideToggle: isVisible">
            Now you see me!
            </div>
        </div>
    </div>
</body>
</html>

The 10/100 Rule – Following this one development rule will improve your code

There is a simple guideline that every developer can follow that will make their code easier to manage and easier to test.

The 10/100 rule

Question: What is the 10/100 rule?

Answer: It is a simple rule that developers should follow to keep their code concise and clean. It involves keeping in mind two warning signs for bad code.

  • Warning #1 – If a method reaches 10 lines, you need to stop and consider refactoring the method.
  • Warning #2 – If a class reaches 100 lines (comments and brackets included) you should stop and consider refactoring.

Like me, you have probably heard both rules before. I see the rule to keep methods short written over and over again in other blogs and other software engineer’s guidelines. But I rarely see this touted as the #1 most important rule that all developers should learn first.

Why should developers learn the 100/10 rule first?

Because it is the single most effective rule to improve code that any developer can learn in less than a minute. No other rule can be learned in other a minute and improve a developers code as much.

I gave this rule to a first year developer (not college educated) and after following this rule, he wrote “proof of concept” code. As many more experienced engineers know, proof of concept code sometimes becomes release code. It is usually a horrible tragedy when this happens. The code is usually rough and untestable and filled with scripting or linear processing. However, in this case, that issue didn’t occur. All the classes were under 100 lines (most considerably under 100 lines). All the method were easily testable and under 10 lines. Sure there were a few that needed to be broken up. The code wasn’t perfect. But the most important and amazing thing about his code were the design patterns he used without even knowing them. He used the proxy and bridge patterns. He used the builder pattern. He used a rudimentary version of the Factory Pattern. He had small and easily manageable singletons. I even found the chain of responsiblity pattern in his code. He also had a number of “Extension methods” since he was using C# which further increased the easy of testing and the readability of his code.

When a developer asks me if they should study design guidelines and learn the many design patterns common to the industry I say, “Yes, of course study them.” However, if a developer follows the rules above, they will naturally find themselves using many of these patterns without even knowing them. It is the perfect rule to keep your code inline until you are an expert.

Why does the 100/10 rule work?

Look at the first year developer’s experience. His code wasn’t perfect, but just the effort he took to keep the classes under 100 lines the methods under 10 lines forced him to create other objects that made more sense for the task at hand. These other objects naturally fell into the realm of well-known design patterns. It works because all the classes are kept small.

The 100/10 rules helps with the Keep it simple stupid (KISS) rule.

The 100/10 rule helps with the Single Responsibility Principle (SRP),  though it doesn’t guarantee the SRP, it helps users naturally stay close to that rule. Sure they may have C# class do two things instead of one because two things fit in the 100 lines allowed for a class. However, how many times have you touched someone else’s code and found a class doing a dozen things in a class that is more than 500 or 1000 lines. To fix this code you have to redesign and break this class into a dozen or more other objects. I think you would be more than happy to only have a class doing two things. Sure you need to break it still, but you only need to break it in half, which is much easier.

It is a guideline that can be broken

The 100/10 rule is a guideline. When a class reaches 100 lines you stop and think. When a method reaches 10 lines, you stop and think. However, thinking is the most important part. Should this method take 10 lines? Maybe it should. Should this class be longer than 100 lines? Maybe it should.

You may have to implement an interface (such as IList) and when you are done, your class is already over 100 lines and you haven’t even added any methods other than the interface’s methods. Well, some might argue that the developers of your interface could have used a smaller interface but there is usually nothing you can do about that. This class isn’t going to be able to follow that 100/10 rule. That is OK.

Keep studying

Remember the 100/10 rule takes less than one minute to learn. It is the single most effective rule a developer can learn in 1 minute to improve their code. It is not the end.

Sure, this rule is always good to follow, even for senior developers, however, this rule doesn’t solve everything. It doesn’t teach interface-based design and good decoupling. It doesn’t make developers follow the open/closed principle or the substitution principle. However, it usually prevents code from becoming spaghetti code. The 100/10 rule keeps the blocks small and easily to work with and easy to fix. So when you see the code and you have to revamp it to include dependency injection and decouple it, you will have a much easier time.

Senior Developers Benefit too

New developers aren’t going to have any idea what cross-cutting concerns are. They will accept that some instance where the 100/10 rule is broken that maybe a senior developer shouldn’t accept. Senior developers should have heard of cross-cutting concerns and should have at least heard of Aspect Oriented Programming (AOP). Often when a method is probably kept in scope, but still reaches over 10 lines, it may be using a try/catch block.

Check out this code found in a single method. The stub code alone is 35 lines. With the missing log, the method was over 50 lines. Is this acceptable just because it is doing a try/catch block?

public StreamReader TryReadFile(string path)
{
    try
    {
        return File.OpenText(path);
    }
    catch (UnauthorizedAccessException ane)
    {
        // handle exception
    }
    catch (ArgumentNullException ane)
    {
        // handle exception
    }
    catch (ArgumentException ane)
    {
        // handle exception
    }
    catch (PathTooLongException ane)
    {
        // handle exception
    }
    catch (DirectoryNotFoundException ane)
    {
        // handle exception
    }
    catch (FileNotFoundException ane)
    {
        // handle exception
    }
    catch (NotSupportedException ane)
    {
        // handle exception
    }
}

Well, if you don’t accept this as OK, (well, the cyclomatic complexity is high why would you accept this as OK?) and you seek out how to resolve this, you are going to run across AOP solutions. With AOP, this method could look like this:

[HandeFileReadExceptionsAspect]
public void TryReadFile(string path)
{
    File.OpenText(path);
}

The HandeFileReadExceptionsAspect is now a separate class that is reusable for every instance where you read a file. You now have common code handling the File.Read exceptions and your method that was 50 lines is now 5 lines. Your HandeFileReadExceptionsAspect class will most likely be under 100 lines. So your codes is now cleaner, more decoupled, easier to read, easier to use, and follows the 100/10 rule.

Conclusion

I preach the 100/10 rule to all developers, new and old. I am not sure that anyone else calls it the 100/10 rule. If you call it something else, let me know.


PC-BSD 10 now available

PC-BSD 10.0-RELEASE is now available for download!

10.0-RELEASE notable features

  • Includes FreeBSD 10.0-RELEASE
  • Updated KMS / AMD driver support
  • ISO file is a hybrid USB file, and can be “dd“ed to a USB media.
  • New text-based installer
  • Able to select between GRUB/BSD loaders during installation
  • New desktops! Gnome 3, Mate (Replaces Gnome2) and Cinnamon

Read More . . .