Layer (or abstraction level, or a layer of abstraction) is a way of hiding the implementation details of a particular set of functionality.
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Is programming in layers real? [duplicate]
I am fairly new in product development and I am trying to work over a product. The problem that I have realized is that people draw diagrams and charts showing different modules and layers.
But as I ...
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1answer
70 views
Layer style applied, but intuition is different
Currently, I'm developing an architecture for a system of the following kind:
There are a couple of existing applications (front end) with which one can define UML profiles capturing some specific ...
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3answers
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How do I create a simple yet complex business layer?
I'm working with a fairly complex web application. It's split up into the following layers:
Presentation - HTML
Service layer - A REST and SOAP API communicating with the business layer
Business ...
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0answers
34 views
Layer Encapsulation without Model Overload?
I'm starting a new project, so it's time to re-evaluate how I do things.
In the recent past I have created a 3 layer/tier project (UI, Domain, Data) with each tier with it's own separate model. The ...
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votes
3answers
96 views
Efficiently “moving” data upward through a communication stack
I have implemented an application protocol stack that moves an incoming stream of data upward through several layers, as follows:
copies a TCP segment from an OS buffer to my_buffer.
after ...
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vote
3answers
200 views
Which layer does async code belong?
I am developing an application that consumes data from an external service. The application is being implemented following a typical layered architecture with UI, Presentation, Domain and Data ...
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1answer
459 views
Trying to understand 3 layer programming [closed]
I am confused to understand the structure of a 3 layer programm. Where is good place for exceptions, entity and etc.? If I use MVC, in my UI model, how to transfer entity class to model class and ...
52
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12answers
4k views
Why is it a good idea for “lower” application layers not to be aware of “higher” ones?
In a typical (well-designed) MVC web app, the database is not aware of the model code, the model code is not aware of the controller code, and the controller code is not aware of the view code. (I ...
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1answer
240 views
Why doesn't layered architecture translate easily to tiered architecture?
Basically, I'm trying to understand why layered and tiered are that different, and why they don't translate easily to each other.
I understand that layered could be 3 separate class files for UI, BL ...
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4answers
161 views
Large teams with layered application
I work in a fairly large team (~15 developers) which is currently discussing our working methodology. The software we work on is quite feature-rich and expanding rapidly in terms of scope so the ...
5
votes
2answers
699 views
How do the Application and Database Interface Layers interact at their boundary?
I was watching one of Uncle Bob's videos and he brought up the Database Interface Layer. He had this diagram showing it:
These arrows show that the DB Interface Layer is aware of and calls the ...
5
votes
3answers
314 views
Good practices to implement mappers in a multi-tier application
When you are working with a multi-tier application very often you run into task of converting objects in one layer to objects in another layer. This could be converting database objects into domain ...
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2answers
506 views
Presentation VS Application layer in DDD
I have trouble drawing a clear line between Presentation and Application layer in Domain Driven Design.
Where should Controllers, Views, Layouts, Javascript and CSS files go?
Is it in the ...
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vote
1answer
136 views
When do domain concepts become application constructs?
I recently posted a question regarding recovering a DDD architecture that became an anemic domain model into a multitier architecture and this question is a follow-on of sorts.
My question is when ...
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4answers
2k views
Do stored procedures violate three-tier separation?
Some colleagues of mine have told me that having business logic in stored procedures in the database violates the three-tier separation, since the database belongs to the data layer whereas stored ...
0
votes
3answers
1k views
PHP - Data Access Layer
I am currently reviewing a code base and noticed that a majority of the calls (along with DB connections) are just buried inside the PHP scripts. I would have assumed that like other languages they ...
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votes
4answers
270 views
Processing a stream. Must layers be violated?
Theoretical situation:
One trillion foobars are stored in a text file (no fancy databases). Each foobar must have some business logic executed on it. A set of 1 trillion will not fit in memory so the ...
0
votes
6answers
1k views
When to use the 3 layers model?
I was recently exposed to the three layer model (DAL,BL,UI). Someone told me I should ALWAYS work with this model.
I have a medium project that I'm starting and I have doubts whether I should build ...
11
votes
2answers
3k views
Does it make sense to use ORM in Android development?
Does it make sense to use an ORM in Android development or is the framework optimized for a tighter coupling between the UI and the DB layer?
Background: I've just started with Android development, ...
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vote
3answers
437 views
Event driven design and separation of core/UI logic
I am new to event driven development, and I feel lost when I try to implement events that should pass the core/UI boundary.
In my program I have the following (example in c#):
UI.RuleForm ...
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vote
1answer
332 views
Effective programming of data layer management/access
Short Version: What is the term/concept which describes the efficient design of programming the data layer for efficient data access and what are some sources/books/articles/website which discuss this ...
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3answers
1k views
Validation and authorization in layered architecture
I know you are thinking (or maybe yelling), "not another question asking where validation belongs in a layered architecture?!?" Well, yes, but hopefully this will be a little bit of a different take ...
3
votes
3answers
174 views
What are the pros and cons of implementing this requirement in different layers?
I have a CRUD app for <DomainObject>s. They are persisted in a database.
There is a new requirement: keep track of the <DomainObject>s that have been created since the app was opened, ...
6
votes
4answers
914 views
n-layers architecture design, really worth the effort?
I was building an application in .Net for almost a year (almost alone), I took the decision to build it with a 3-layer design. Recently when finished the project, I analyzed if the effort of creating ...
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3answers
5k views
Entity Framework and layer separation
I'm trying to work a bit with Entity Framework and I got a question regarding the separation of layers.
I usually use the UI -> BLL -> DAL approach and I'm wondering how to use EF here.
My DAL would ...
5
votes
2answers
108 views
How to document/verify consistent layering?
I have recently moved to the dark side: I am now a CUSTOMER of software development -- mainly websites. With this new role comes new concerns.
As a programmer i know how solid an application ...
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votes
3answers
495 views
Recommended content for layers
As an expansion from my previous question about using separate projects for seperate layers - Good practice on Visual Studio Solutions
I now wish to know if I am putting the right functionality in ...
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votes
2answers
1k views
GUI, BLL, DAL Organization In A Project
I'm reading about application layers, and want to use this design in my next project (c#, .Net). Some questions:
Is the separation of layers done through namespaces? Project.BLL.Whatever, ...
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1answer
985 views
What are “User Process Components”?
This article about application architecture design mentions "User Process Components" as part of the presentation layer.
User process components. Your user process components help synchronize and ...
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7answers
585 views
Can it be useful to build an application starting with the GUI?
The trend in application design and development seems to be starting with the "guts": the domain, then data access, then infrastructure, etc. The GUI seems to usually come later in the process. I ...
