Allows business rules to be recombined by chaining the business rules together using boolean logic. The pattern is frequently used in the context of domain-driven design.
Questions tagged [specification-pattern]
114 questions
6
votes
3 answers
Repository and Specification pattern
I'm currently setting up a new project, and I have run into a few things, where I need a little input.
This is what i'm considering:
I would like a generic repository
I don't want to return IQueryable from my repository.
I would like to encapsulate…
Luhmann
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5
votes
3 answers
Specification inside LINQ with EF 4.3
I stumbled trying to use my specification inside a LINQ query. The trouble here is with my specification with params.
Let's fake a simple scenario:
public class Car {
public Guid Id { get; set; }
public string Color { get; set; }
public…
Kim Tranjan
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5
votes
1 answer
Combining C# code and database code in a Specification
Sometimes you need to define some business rules and the Specification pattern is a useful tool. For example:
public class CanBorrowBooksSpec : ISpecification
{
public bool Satisfies(Customer customer)
{
return…
cbp
- 25,252
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5
votes
2 answers
EF Core Specification pattern add all column for sorting data with custom specification
I applied Specification Pattern for my .net core project.
I also created custom specification for Include, Sorting, Paging etc.
I get sort value from api url with queryString and passing to custom specification class.
In this class i added some…
TheMuyu
- 579
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5
votes
1 answer
JPA Specification and null parameter in .where clause
I wrote two Specifications which return null if their parameter is null.
public static Specification getProdottoByLineaSpec (String linea) {
if (linea != null) {
return (root, query, criteriaBuilder) -> {
…
4javier
- 481
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5
votes
0 answers
How to combine specification pattern with raw sql
I try to implement some application in DDD manner with CQRS. I use asp.net core application, and as well as Microsofts (in the microservices book) I use Mediatr.
I want to implement filtering of articles. For that purpose, people advise to use…
Andriy
- 362
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- 16
5
votes
2 answers
Using eager loading with specification pattern
I've implemented the specification pattern with Linq as outlined here https://www.packtpub.com/article/nhibernate-3-using-linq-specifications-data-access-layer
I now want to add the ability to eager load and am unsure about the best way to go about…
Simon
- 1,499
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4
votes
1 answer
How can one define the Selector in ardalis.Specification library?
I am trying to utilize the Ardalis.Specification library to apply the specification pattern in my asp.net 6 project.
After installing the library, I created the following specification
public class ProductByIdsSpec : Specification
Jay
- 1,168
- 13
- 41
4
votes
1 answer
Type does not satisfy the constraint and incorrectly extends interface when trying to implement generic Specification and Visitor patterns
I'm trying to implement a generic Specification pattern and a generic Visitor pattern together. Here are my base interfaces.
export interface Specification> {
accept(visitor: TVisitor): void;
…
snowfrogdev
- 5,963
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4
votes
1 answer
Exclude null or empty string value from lambda expression
In my app in GetAll function I have a parameter which is called (CustomerModel). I use it to do some filtering over the query and I used specification pattern to avoid using if-else :
public async Task>…
peyman gilmour
- 1,168
- 2
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- 35
4
votes
1 answer
good way to implement NotSpecification: isSpecialCaseOf?
I'm implementing the specification pattern. The NotSpecification seems simple at first:
NotSpecification.IsSpecialCaseOf(otherSpecification)
return !this.specification.isSpecialCaseOf(otherSpecification)
But it doesn't work for all…
koen
- 13,349
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4
votes
2 answers
How to apply multiple filter conditions (simultaneously) on a list?
I have following C# code with .Net 4.0 framework. This is created after referring The Specification Pattern - by Jeff Perrin
In the GetProducts() the conditions to be used are defined (hard coded) inside the method. There is another method named…
LCJ
- 22,196
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4
votes
1 answer
PHP specification pattern that allows transformation to sql
I'm trying to find out what the best way would be to have a specification pattern in PHP where the specifications could (optionally) by transformed to PHP.
I am exploring some new directions and am testing how well they would work. Code and ideas…
koen
- 13,349
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4
votes
4 answers
Specification Pattern defined in Domain
Using Linq to SQL, and a DDD style Domain Layer with de-coupled repositories, does anyone have any good ideas on how to implement a specification pattern without bleeding L2S concerns up into the domain layer, that is still understandable? :)
We…
jlembke
- 13,217
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4
votes
1 answer
Extending LINQ-based Specification Pattern to implement subsumption
There are a lot of LINQ-based implementations of the Composite Specification Pattern. I have not seen one that used Subsumption.
Are there any such examples that have been documented (blogs, etc.) or published as open source? I have an idea and…
smartcaveman
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