Currently I have a bunch of if else statements to set CategoryId's based on how many items are in each collection.
For example,
public class TeamWork
{
public string EmployeeName { get; set; }
public int CategoryId { get; set; }
}
public class BLL
{
public void SetCategoryId(ICollection<TeamWork> Converted, ICollection<TeamWork> Sourced)
{
if (Converted.Count == 1 && Sourced.Count == 1)
{
if (String.Compare(Sourced.First().EmployeeName, Converted.First().EmployeeName) == 0)
{
// set category id to 1
Converted.First().CategoryId = 1;
Sourced.First().CategoryId = 1;
}
else
{
// set category id to something
}
}
else if (Sourced.Rows.Count == 1 && Converted.Rows.Count > 1)
{
// set category id to something
}
// more if else statements...
}
}
I think there's a better way to do this perhaps by applying some design pattern. Any suggestions? Thanks!
Chain of responsibility is the way to go.
So this object is passed to a series of command objects until one is able to act upon and set the status.
A Strategy pattern comes to mind. Try to break these rules down into a series of "if this condition is true, then the category ID is this". Make each one of these a method, then add those methods as delegates to a List<Func<ICollection<TeamWork>, ICollection<TeamWork>, bool>> or a comparable indexed collection. Then, your SetCategoryId() code looks like this:
public void SetCategoryId(ICollection<TeamWork> Converted, ICollection<TeamWork> Sourced)
{
foreach(var categoryRule in CategoryRules)
{
var category = test(Converted, Sourced);
if(category != 0)
{
Converted.First().CategoryId = Sourced.First().CategoryId = category;
break;
}
}
}
The above code would never have to change regardless of how many rules you added or removed. However, with the if - else if structure you have, your series of rules will likely be order-dependent, so be careful when setting up the rules in the list.
Related
I have a class ScoreStrategy that describes how to calculate points for a quiz:
public class ScoreStrategy
{
public int Id { get; set; }
public int QuizId { get; set; }
[Required]
public Quiz Quiz { get; set; }
public decimal Correct { get; set; }
public decimal Incorrect { get; set; }
public decimal Unattempted { get; set; }
}
Three properties Correct, Incorrect and Unattempted describe how many points to be assigned for a response. These points can also be negative. The score strategy applies to all questions in the quiz, thus there can only be one ScoreStrategy per quiz.
I have two subclasses:
public class DifficultyScoreStrategy : ScoreStrategy
{
public QuestionDifficulty Difficulty { get; set; }
}
public class QuestionScoreStrategy : ScoreStrategy
{
[Required]
public Question Question { get; set; }
}
My questions have three difficulty levels(Easy, Medium, Hard; QuestionDifficulty is an enum). The DifficultyScoreStrategy specifies if points for questions of a specific difficulty need to be assigned differently. This overrides the base ScoreStrategy that applies to the entire quiz. There can be one instance per difficulty level.
Thirdly, I have a QuestionScoreStrategy class that specifies if points for a specific question have to be awarded differently. This overrides both the quiz-wide ScoreStrategy and the difficulty-wide DifficultyStrategy. There can be one instance per question.
While evaluating the responses of the quiz, I want to implement a level-by-level fallback mechanism:
For each question:
Check if there is a QuestionScoreStrategy for the question and return the strategy if one is found.
If not, fallback to DifficultyScoreStrategy and check if there is a strategy for the difficulty level of the question being evaluated
and return it if a strategy is found.
If not, fallback to the quiz-wide ScoreStrategy and check if one exists and return it if it does,
If there is no ScoreStrategy either, use default as { Correct = 1, Incorrect = 0, Unattempted = 0 }(It would be great if I can make this configurable as well, something much like the .NET's elegant way:
options => {
options.UseFallbackStrategy(
correct: 1,
incorrect: 0,
unattempted: 0
);
}
).
Summary
I've summarized the above info in a table:
Strategy Type
Priority
Maximum instances per quiz
QuestionScoreStrategy
1st (highest)
As many as there are questions in the quiz
DifficultyScoreStrategy
2nd
4, one for each difficulty level
ScoreStrategy
3rd
Only one
Fallback strategy (Default { Correct = 1, Incorrect = 0, Unattempted = 0})
4th (lowest)
Configured for the entire app. Shared by all quizzes
I have a container class called EvaluationStrategy that holds these score strategies among other evaluation info:
partial class EvaluationStrategy
{
public int Id { get; set; }
public int QuizId { get; set; }
public decimal MaxScore { get; set; }
public decimal PassingScore { get; get; }
public IEnumerable<ScoreStrategy> ScoreStrategies { get; set; }
}
What I have tried:
I have added a method called GetStrategyByQuestion() to the same EvaluationStrategy class above(note it is declared as partial) that implements this fallback behavior and also a companion indexer that in turn calls this method. I have declared two HashSets of types DifficultyScoreStrategy and QuestionScoreStrategy and an Initialize() method instantiates them. All the score strategies are then switched by type and added to the appropriate HashSet, there can only be one ScoreStrategy per quiz, which will be stored in defaultStrategy:
partial class EvaluationStrategy
{
private ScoreStrategy FallbackStrategy = new() { Correct = 1, Incorrect = 0, Unattempted = 0 };
private ScoreStrategy defaultStrategy;
HashSet<DifficultyScoreStrategy> dStrategies;
HashSet<QuestionScoreStrategy> qStrategies;
public void Initialize()
{
qStrategies = new();
dStrategies = new();
// Group strategies by type
foreach (var strategy in strategies)
{
switch (strategy)
{
case QuestionScoreStrategy qs: qStrategies.Add(qs); break;
case DifficultyScoreStrategy ds: dStrategies.Add(ds); break;
case ScoreStrategy s: defaultStrategy = s; break;
}
}
}
public ScoreStrategy this[Question question] => GetStrategyByQuestion(question);
public ScoreStrategy GetStrategyByQuestion(Question question)
{
if (qStrategies is null || dStrategies is null)
{
Initialize();
}
// Check if question strategy exists
if (qStrategies.FirstOrDefault(str => str.Question.Id == question.Id) is not null and var qs)
{
return qs;
}
// Check if difficulty strategy exists
if (dStrategies.FirstOrDefault(str => str.Question.Difficulty == question.Difficulty) is not null and var ds)
{
return ds;
}
// Check if default strategy exists
if (defaultStrategy is not null)
{
return defaultStrategy;
}
// Fallback
return FallbackStrategy;
}
}
This method seems a bit clumsy and doesn't quite feel right to me. Using a partial class and adding to EvalutationStrategy doesn't seem right either. How do I implement this level-by-level fallback behavior? Is there a design pattern/principle I can use here? I know many things in the .NET framework fallback to default conventions if not configured. I need something similar. Or can someone simply recommend a cleaner and elegant solution with better maintainability?
NOTE/ADDITIONAL INFO: The ScoreStrategys and EvaluationStrategy for all quizzes are stored in a database managed by EF Core(.NET 5) with TPH mapping:
modelBuilder.Entity<ScoreStrategy>()
.ToTable("ScoreStrategy")
.HasDiscriminator<int>("StrategyType")
.HasValue<ScoreStrategy>(0)
.HasValue<DifficultyScoreStrategy>(1)
.HasValue<QuestionScoreStrategy>(2)
;
modelBuilder.Entity<EvaluationStrategy>().ToTable("EvaluationStrategy");
I have a single base DbSet<ScoreStrategy> ScoreStrategies and another DbSet<EvaluationStrategy> EvaluationStrategies. Since EvaluationStrategy is an EF Core class, I'm a bit skeptical about adding logic(GetStrategyByQuestion()) to it as well.
With Polly
There is a 3rd party library called Polly which defines a policy called Fallback.
With this approach you can easily define a fallback chain like this:
public ScoreStrategy GetStrategyByQuestionWithPolly(Question question)
{
Func<ScoreStrategy, bool> notFound = strategy => strategy is null;
var lastFallback = Policy<ScoreStrategy>
.HandleResult(notFound)
.Fallback(FallbackStrategy);
var defaultFallback = Policy<ScoreStrategy>
.HandleResult(notFound)
.Fallback(defaultStrategy);
var difficultyFallback = Policy<ScoreStrategy>
.HandleResult(notFound)
.Fallback(() => GetApplicableDifficultyScoreStrategy(question));
var fallbackChain = Policy.Wrap(lastFallback, defaultFallback, difficultyFallback);
fallbackChain.Execute(() => GetApplicableQuestionScoreStrategy(question));
}
I've extracted the strategy selection logic for QuestionScoreStrategy and DifficultyScoreStrategy like this:
private ScoreStrategy GetApplicableQuestionScoreStrategy(Question question)
=> qStrategies.FirstOrDefault(str => str.Question.Id == question.Id);
private ScoreStrategy GetApplicableDifficultyScoreStrategy(Question question)
=> dStrategies.FirstOrDefault(str => str.Difficulty == question.Difficulty);
Pros
There is a single return statement
The policy declarations are separated from chaining
Each and every fallback can be triggered by different conditions
Primary selection logic is separated from the fallbacks
Cons
The code is really repetitive
You can't create a fallback chain by utilizing a fluent API
You need to use a 3rd party library
Without Polly
If you don't want to use a 3rd party library just to define and use a fallback chain you do something like this:
public ScoreStrategy GetStrategyBasedOnQuestion(Question question)
{
var fallbackChain = new List<Func<ScoreStrategy>>
{
() => GetApplicableQuestionScoreStrategy(question),
() => GetApplicableDifficultyScoreStrategy(question),
() => defaultStrategy,
() => FallbackStrategy
};
ScoreStrategy selectedStrategy = null;
foreach (var strategySelector in fallbackChain)
{
selectedStrategy = strategySelector();
if (selectedStrategy is not null)
break;
}
return selectedStrategy;
}
Pros
There is a single return statement
The fallback chain declaration and evaluation are separated
It is simple and concise
Cons
It is less flexible: each fallback selection is triggered by the same condition
Primary selection is not separated from fallbacks
You can sort the sequence of ScoringMethods by your priority.
First you sort by whether str is QuestionScoreStrategy and str.Question.Id == question.Id.
Then you sort by whether str is DifficultyScoreStrategy and str.Question.Difficulty == question.Difficulty.
(Note that since false comes before true, you'll have to invert the conditions)
Then you can just do FirstOrDefault() ?? defaultStrategy.
Example:
var defaultStrategy = new() { Correct = 1, Incorrect = 0, Unattempted = 0 };
var selectedStrategy = Strategies.OrderBy(str =>
!(str is QuestionScoreStrategy questionStrat && questionStrat.Question.Id == question.Id)
).ThenBy(str =>
!(str is DifficultyScoreStrategy difficultySrat && difficultySrat.Difficulty == question.Difficulty)
).FirstOrDefault() ?? defaultStrategy;
You can easily add more "levels" to this by adding more ThenBy clauses.
I imagine that all data (questions, strategies, quizes is stored in database). Then I would expect such ways of getting each strategy:
Question strategy
var questionStrategy = dbContext.ScoreStrategies.SingleOrDefault(ss => ss.QuesionId == question.Id);
Difficulty strategy:
var difficultyStrategy = dbContext.ScoreStrategies.SingleOrDefault(ss => ss.Difficulty == question.Difficulty);
Default strategy for quiz:
var quizStrategy = dbContext.ScoreStrategies.SingleOrDefault(ss => ss.QuizId == question.QuizId)
Building on this and what you already provided, strategy is just three numbers: points for correct answer, points for incorrect and unattempted answer.
So this makes perfect candidate for abstract class, which would serve for base class for three entities - three types of strategy - those will be three tables, because each has different relations:
public abstract class ScoreStrategy
{
public double Correct { get; set; }
public double Incorrect { get; set; }
public double Unattempted { get; set; }
}
// Table with FK relation to Questions table
public class QuestionScoreStrategy : ScoreStrategy
{
public Question { get; set; }
public int QuestionId { get; set; }
}
// If you have table with difficulties, there should be FK relation to it.
// If you do not have table - it's worth consideration, you could then
// easily add more difficulties.
public class DifficultyStrategy : ScoreStrategy
{
public QuestionDifficulty Difficulty { get; set; }
}
// FK relation to Quizes table
public class QuizScoreStrategy : ScoreStrategy
{
public Quiz { get; set; }
public int QuizId { get; set; }
}
This way you end up with well grained tables that stores only relevant data.
Then, usage would become:
// Ideally, this method should be in some repoistory (look at repository design pattern) in data access layer
// and should leverage usage of async / await as well.
public ScoreStrategy GetScoreStrategy(Question question)
{
return dbContext.QuestionScoreStrategies.SingleOrDefault(qs => qs.QuestionId == question.Id)
?? dbContext.DifficultyStrategies.SingleOrDefault(ds => ds.Difficulty == question.Difficulty)
?? dbContext.QuizScoreStrategies.SingleOrDefault(qs => qs.QuizId == question.QuizId);
}
Then you could use this method in such way:
// This should be outside data access layer. Here you perform logic of getting question.
// This could be some ScoringManager class which should be singleton (one instance only).
// Then you could define fallback in private fields:
private readonly double FALLBACK_CORRECT_SCORE;
private readonly double FALLBACK_INCORRECT_SCORE;
private readonly double FALLBACK_UNATTEMPTED_SCORE;
// private constructor, as this should be singleton
private ScoringManager(double correctScore, double incorrectScore, double unattemptedScore)
=> (FALLBACK_CORRECT_SCORE, FALLBACK_INCORRECT_SCORE, FALLBACK_UNATTEMPTED_SCORE) =
(correctScore, incorrectScore, unattemptedScore);
public double CalcScoreForQuestion(Question question)
{
var scoreStrategy = GetScoreStrategy(question);
if (question answered correctly)
return scoreStrategy?.Correct ?? FALLBACK_CORRECT_SCORE;
if (question answered incorrectly)
return scoreStrategy?.Incorrect ?? FALLBACK_INCORRECT_SCORE;
if (question unattempted)
return scoreStrategy?.Unattempted ?? FALLBACK_UNATTEMPTED_SCORE;
}
NOTE
This is just the draft how I would organize things and most probably when writing code I would come up with improvements, but I think this is direction to go. For example ScoringManager could have ConfigureFallbackScore method, which would allow dynamically changing fallback scores (this would require making respective fields not readonly).
UPDATE
Define fallback strategy, in order to do that define enum:
public enum FallbackLevel
{
Difficulty,
Question,
Quiz,
}
Then scoring manager could have method to configure strategy (together with backing fields):
private FallbackLevel _highPrecedence;
private FallbackLevel _mediumPrecedence;
private FallbackLevel _lowPrecedence;
public void ConfigureFallbackStrategy(FallbackLevel highPrecedence, FallbackLevel mediumPrecedence, FallbackLevel lowPrecedence)
{
_highPrecedence = highPrecedence;
_mediumPrecedence = mediumPrecedence;
_lowPrecedence = lowPrecedence;
}
Then we would write getting strategy logic in manager:
public ScoreStrategy GetScoreStrategy(Question question)
{
var scoreStrategy = GetScoreStrategy(_highPrecedence, question)
?? GetScoreStrategy(_mediumPrecedence, question)
?? GetScoreStrategy(_lowPrecedence, question);
}
private ScoreStrategy GetScoreStrategy(FallbackLevel lvl, Question question) => lvl switch
{
FallbackLevel.Difficulty => dbContext.DifficultyStrategies.SingleOrDefault(ds => ds.Difficulty == question.Difficulty),
FallbackLevel.Question => dbContext.QuestionScoreStrategies.SingleOrDefault(qs => qs.QuestionId == question.Id),
FallbackLevel.Quiz => dbContext.QuizScoreStrategies.SingleOrDefault(qs => qs.QuizId == question.QuizId),
}
This way it is super easy to configure fallback strategy any way you want. Of course, there are some considerations still:
make sure that all fallback strategies are unique, so for example it is impossible to have high, medium and low startegy the same,
db context should be accessed only via repository pattern
add some more sanity checks (like nulls etc.)
I omitted those parts, as I focused on sheer functionality.
I have below class object structure with having three inner objects and i am trying to check that only one child object should have the data other wise throw an error and i can do this with if- else statements but looking to see any other way to implement this
public class GlazingOrGasMaterial
{
public GlazingComplexMaterial GlazingComplexMaterial { get; set; }
public GlazingSimpleMaterial GlazingSimpleMaterial { get; set; }
public GlazingGasMaterial GlazingGasMaterial { get; set; }
public GlazingOrGasMaterial(GlazingOrGasMaterial layer)
{
if (layer.GlazingComplexMaterial != null && layer.GlazingGasMaterial != null && layer.GlazingSimpleMaterial == null)
{
throw new ArgumentException("exception for more than one object having data");
}
// more if statements
}
}
and i am calling this constructor like as in below
foreach(var layer in input.Layers)
{
GlazingOrGasMaterial glazingOrGasMaterial = new GlazingOrGasMaterial(layer);
}
Could any one please let me know any way to do this escaping bunch of if-else statements, many thanks in advance
Actually, according OOP, other guys are right, you had better change your class strategy. But I don't know the whole task so I'm able to give an advice only.
I also provided another solution of your question according to your requirements:
public GlazingOrGasMaterial(GlazingOrGasMaterial layer)
{
BitArray materialBits = new BitArray(new bool[] { layer.GlazingComplexMaterial != null, layer.GlazingGasMaterial != null, layer.GlazingSimpleMaterial != null });
byte[] array = new byte[1]; // max number of states depends on the type: byte - 8, short - 16 etc.
materialBits.CopyTo (array, 0);
byte materialState = array[0];
if((materialState != 0) && ((materialState & (materialState - 1)) == 0)) //check if only 1 property has a data
throw new ArgumentException("exception for more than one object having data");
else
//do what you wish
//an example, using by switch you could recognize the exactly not null property
}
How about creating a collection from your objects and counting the ones which meet your expectation:
public GlazingOrGasMaterial(GlazingOrGasMaterial layer)
{
if (new object[] { layer.GlazingComplexMaterial, layer.GlazingSimpleMaterial, layer.GlazingGasMaterial }.Count(x => x != null) != 1)
{
throw new ArgumentException("Expected only one material");
}
...
}
I think you could also consider using a different data modeling approach to enforce this requirement - for example, you could make all of the materials inherit from abstract BaseMaterial and then have the "container" class (if you'd still need it) with only one BaseMaterial property instead of 3 separate ones.
I suggest you change the shape of your class to enforce the 1 material rule. If all the possible materials extend from a common material, then you can create this base class and only allow one instance.
public class GlazingOrGasMaterial
{
public Material _material { get; set; }
public GlazingOrGasMaterial(Material material)
{
_material = material;
}
}
public class Material
{
}
public class GlazingComplexMaterial : Material
{
}
public class GlazingSimpleMaterial : Material
{
}
public class GlazingGasMaterial : Material
{
}
You can then instantiate the class with one of the materials without having to worry that there are multiple. This avoids runtime exceptions!
void Main()
{
var material = new GlazingComplexMaterial();
new GlazingOrGasMaterial(material);
}
This also avoids the problem in the original design where a 2nd or even 3rd material can just be assigned, without going through the constructor validation logic.
I have a question regarding the filtering of an ObservableCollection (and its children).
I have the following class:
public class SomeClass
{
public string Description { get; set; }
public string CodeFlag { get; set; }
public double Price { get; set; }
public List<SomeClass> Children { get; set; }
public SomeClass()
{
this.Children = new List<SomeClass>();
}
public SomeClass Search(Func<SomeClass, bool> predicate)
{
// the node is a leaf
if (this.Children == null || this.Children.Count == 0)
{
if (predicate(this))
return this;
else
return null;
}
else // the node is a branch
{
var results = Children.Select(i => i.Search(predicate)).Where(i => i != null).ToList();
if (results.Any())
{
var result = (SomeClass)MemberwiseClone();
result.Children = results;
return result;
}
/*
* this is where I'm struggling
*/
return null;
}
}
}
And in the view model the following properties:
private ObservableCollection<SomeClass> originalDataSource;
public ObservableCollection<SomeClass> TreeViewDataSource { get; set; }
The originalDataSource is set in the constructor whilst the TreeViewDataSource is the collection bound to the TreeView.
I'm certain that there are better ways to accomplish this, (i.e. have just the one collection) but I'm happy with this for now.
Initially, all of the items in the collection are to be shown - I simply show the Description, Code and Price properties for each item, so far so good.
Now, the view model is informed that the current filter has changed so I want to be able to filter as such.
An example could be to show all items where “CodeFlag” is “ABC” or “XYZ”.
If the filter has changed, I set the TreeViewDataSource as such:
this.TreeViewDataSource = _getFilteredList(this.originalDataSource);
private ObservableCollection<SomeClass> _getFilteredList(ObservableCollection<SomeClass> originalList)
{
var filteredItems = new ObservableCollection<SomeClass>();
SomeClass filterResults = null;
switch (this.SelectedFilter)
{
case SomeEnum.SomeFilterOption:
filterResults = originalList[0].Search(x => x.CodeFlag.Equals("ABC") || x.CodeFlag.Equals("XYZ"));
break;
default:
break;
}
filteredItems.Add(filterResults);
return filteredItems;
}
This almost works as expected.
Where it is not working as expected is if an item has children where the filter does NOT apply.
In this scenario, even though the item itself matches the filter, as its children do not, null is returned.
The
/*
* this is where I'm struggling
*/
comment is where I believe I need additional logic.
Please note, the credit for the original Search method goes to #tono-nam
As it's the Weekend and I may be in a different time zone as that of the vast majority of you, please do not be offended if I do not respond straight away!
Have a great weekend!
You don't need an ObservableCollection for the items you're going to show, since the entire collection changes at once. You can simply use e.g. an array, and let the parent class implement INotifyPropertyChanged to notify the fact that the entire collection has changed.
To answer your question about what to return instead of null, use the same logic you use for leaves: return the item if it matches the predicate and null otherwise.
You can simplify your code by reordering the conditions: first get all children that satisfy the predicate, and if there are none (either because there are no children, or because there are children but they don't match - doesn't matter) then treat the collection as a leaf.
I'm using EF4.3 so I'm referring to entities, however it could apply to any class containing properties.
I'm trying to figure out if its possible to compare 2 entities. Each entity has properties that are assigned values for clarity let say the entity is 'Customer'.
public partial class Customer
{
public string Name { get; set; }
public DateTime DateOfBirth { get; set; }
...
...
}
The customer visits my website and types in some details 'TypedCustomer'. I check this against the database and if some of the data matches, I return a record from the database 'StoredCustomer'.
So at this point I've identified that its the same customer returning but I wan't to valid the rest of the data. I could check each property one by one, but there are a fair few to check. Is it possible to make this comparison at a higher level which takes into account the current values of each?
if(TypedCustomer == StoredCustomer)
{
.... do something
}
If you're storing these things in the database, it is logical to assume you'd also have a primary key called something like Id.
public partial class Customer
{
public int Id { get; set; }
public string Name { get; set; }
public DateTime DateOfBirth { get; set; }
...
...
}
Then all you do is:
if(TypedCustomer.Id == StoredCustomer.Id)
{
}
UPDATE:
In my project, I have a comparer for these circumstances:
public sealed class POCOComparer<TPOCO> : IEqualityComparer<TPOCO> where TPOCO : class
{
public bool Equals(TPOCO poco1, TPOCO poco2)
{
if (poco1 != null && poco2 != null)
{
bool areSame = true;
foreach(var property in typeof(TPOCO).GetPublicProperties())
{
object v1 = property.GetValue(poco1, null);
object v2 = property.GetValue(poco2, null);
if (!object.Equals(v1, v2))
{
areSame = false;
break;
}
});
return areSame;
}
return poco1 == poco2;
} // eo Equals
public int GetHashCode(TPOCO poco)
{
int hash = 0;
foreach(var property in typeof(TPOCO).GetPublicProperties())
{
object val = property.GetValue(poco, null);
hash += (val == null ? 0 : val.GetHashCode());
});
return hash;
} // eo GetHashCode
} // eo class POCOComparer
Uses an extension method:
public static partial class TypeExtensionMethods
{
public static PropertyInfo[] GetPublicProperties(this Type self)
{
self.ThrowIfDefault("self");
return self.GetProperties(BindingFlags.Public | BindingFlags.Instance).Where((property) => property.GetIndexParameters().Length == 0 && property.CanRead && property.CanWrite).ToArray();
} // eo GetPublicProperties
} // eo class TypeExtensionMethods
Most simple seems to use reflexion : get the properties and/or fields you want to compare, and loop through them to compare your two objects.
This will be done with getType(Customer).getProperties and getType(Customer).getFields, then using getValue on each field/property and comparing.
You might want to add custom informations to your fields/properties to define the ones that needs
comparing. This could be done by defining a AttributeUsageAttribute, that would inherit from FlagsAttribute for instance. You'll then have to retrieve and handle those attributes in your isEqualTo method.
I don't think there's much of a purpose to checking the entire object in this scenario - they'd have to type every property in perfectly exactly as they did before, and a simple "do they match" doesn't really tell you a lot. But assuming that's what you want, I can see a few ways of doing this:
1) Just bite the bullet and compare each field. You can do this by overriding the bool Equals method, or IEquatable<T>.Equals, or just with a custom method.
2) Reflection, looping through the properties - simple if your properties are simple data fields, but more complex if you've got complex types to worry about.
foreach (var prop in typeof(Customer).GetProperties()) {
// needs better property and value validation
bool propertyMatches = prop.GetValue(cust1, null)
.Equals(prop.GetValue(cust2, null));
}
3) Serialization - serialize both objects to XML or JSON, and compare the strings.
// JSON.NET
string s1 = JsonConvert.SerializeObject(cust1);
string s2 = JsonConvert.SerializeObject(cust2);
bool match = s1 == s2;
I have a string containing a C function with condition statements inside.
string inputFunction = "if(x > 10)
{
if(x == 11)
{
//more conditions
}
if(x == 12)
{
}
}";
using regular expression I parse for condition statements then, parse for its code block. then repeat the process again for the next conditions. Then I plan to store them in a class I've created:
class Condition
{
public string ConditionString { get; set; }
public string ParentCondition { get; set; }
public string ChildConditions { get; set; }
}
Now the problem is: I cannot create a parent-child relationship with my current algorithm.
I am only able to identify the first set of parents. I can repeat the process again to parse for their children, but those children can also have child conditions inside. Does anyone have a suggestion or s there a better way of doing this?
For tree structure, the golden rule is to have collection of entity within itself.
I think your class structure should be this
class Condition
{
public string ConditionString{get;set;}
public Condition ParentCondition{get;set;}
public List<Condition> ChildConditions{get;set;} // in case there are more
// than one conditions.
}