Questions about problem solving and planning for a solution through software design.
0
votes
1answer
22 views
How to create good positive and negative images for opencv to distinguish smiling from not smiling?
My goal is to create an opencv haar classifier xml that distinguishes between me smiling and not smiling.
I created images, cut them, showing me smiling and as negatives not smiling. About 5000 ...
2
votes
0answers
42 views
What is the correct approach for creating an application around a library?
I have a library that defines messages. In my particular instance, it's autogenerated code from an XSD using JAXB (Java). The messages can be very complex, with some members as objects and those ...
-1
votes
1answer
21 views
Extracting client specific code. refactoring possibilities required
I am facing a Design problem. I have a set of classes which writes data in XML,JSON or HTML formates for different clients.
I have a class which receives Data and a XML, JSON or HTML writer as it ...
1
vote
1answer
124 views
Is SICP still relevant? [on hold]
Today, I came across this book entitled:The Structure and Interpretation of Computer Programs
I read the Table Of Contents and it really interests, me. It seems to be exactly what I've been looking ...
2
votes
2answers
177 views
Don't repeat yourself vs do only one thing in a method
I am currently writing some test cases in python. I often end up calling the same two or three lines of code at the start of a test case in order to get the program I am testing going. For example:
...
-2
votes
0answers
22 views
Suggestions for design / links for a software that can ask questions? [on hold]
i have a large set of related questions. That i need to ask users one by one and each consecutive questions depends on the answer to the previous question.
Can someone recommend me a good ...
-4
votes
0answers
43 views
Proper architecture of web app using Web Api + asp.net mvc + entity framework and business logic [on hold]
I am looking for a proper architecture (n-tier) where we can combine multiple technologies or frameworks.
The idea is to build an asp.net mvc app that consumes web api, and there should be business ...
3
votes
4answers
121 views
Why use an enum to determine node type in a parse tree?
The Sun Compiler Tree API uses an interface called Tree as the parent of all the different kinds of parse tree nodes (assignments, if-statements, class declarations, etc.). A part of this interface is ...
0
votes
1answer
96 views
2 Classes that share similar behaviours but unrelated.
I'm working on something at the moment and am a little confused.
I'm working on an enquiry system in PHP (it's Opencart Based, so MVC).
An enquiry comes in and depending on what form it was ...
-5
votes
1answer
51 views
Is it possible to add functionality to an existing app? [closed]
I want to add a button to an app, addon style. I don't have the source code of the app but want to add a simple functionality. Using an API, I guess. Is this even possible?
Specific, can I add a ...
1
vote
2answers
73 views
Building CMS from components
I have a design decision problem and would like to have some thoughts on it.
I'm building a CMS to use for my projects and want to incorporate existing components in it, like Doctrine, Monolog and ...
-2
votes
0answers
16 views
Scope in software devlopment after ignou mca with 1 year experience [closed]
I have completed bsc it (64%), 12 th (57%) and 10th (63%). currently doing mca from ignou last sem and working as software devloper (android and core php). i am going to complete mca and 1 yr ...
-2
votes
0answers
27 views
AngularJs with ASP.NET MVC - How to create solution structure [closed]
How and where to place Angular controller files in the ASP.Net MVC solution structure which can be easy to find and maintain?
1
vote
2answers
131 views
Implementing an anti-corruption layer with domain logic
I'm building an application that compiles a single PDF document from multiple source PDF documents as follows: it takes the first page of each source document, stamps certain information on top of ...
0
votes
2answers
102 views
Object oriented Classes and single responsibility [duplicate]
I'm reading a book that explain that it is a good thing that classes have a single responsibility, that is, that they do a single thing.
I can understand how to implement this in some cases I ...
0
votes
0answers
35 views
Reusable tree behaviour implementation of getParent() / getChildren() - Good design? [closed]
Yesterday i had a discussion with my colleague about a strategy to deal with tree behaviours.
We have the following situation: We have a model which has a child / parent relation:
interface ...
5
votes
5answers
299 views
Should the method describe its side effects? [duplicate]
I was reading Clean Code by Bob Martin and there's one particular code smell, related to naming, that looks interesting to me:
N7: Names Should Describe Side-Effects
Names should describe ...
14
votes
5answers
2k views
If Else - Repeated Code Logic
My boss gave me a project with a particular logic. I have to develop a web page which has to lead the navigator through many cases until he/she arrives at the product.
This is the path scheme of the ...
1
vote
1answer
84 views
Running an algorithm against a large dataset
We have a python application which does a DFS search against data in a database. Right now, that data is small so I can hold everything in a python container but the data is going to grow and there ...
1
vote
1answer
115 views
Does Separation of Concerns applies to GUI components?
In an application I developed with C#, I use a webbrowser control, it should navigate to some websites, then I would like to extract some contents from the webpages. I do it by manipulation of DOM and ...
0
votes
0answers
30 views
python: area mapping using trigonometric circle
I have a car controlled by a raspberry pi, I would like to create maps to each place it visits. The solution I came up with is simple. Lets say you tell the car to go forward and then after 5 minutes ...
-1
votes
3answers
119 views
What do design and implementation mean?
The words "design" and "implementation" have been used widely. But I am not sure that I understand them.
What do design and implementation of a computer-related system (e.g.
a computer system, an ...
1
vote
3answers
225 views
Should code comments explain the control flow?
Should comments explain how the application control flow works? For example, the relationships between classes, how this function is used by other functions, and what we are trying to do with these ...
5
votes
2answers
154 views
How to organize predefined queries with Entity Framework?
I have some queries that I use all the time (like get rows only of some specific type, or count something etc.). I'd like to organize them somehow (better then I currently do).
Currently I have them ...
3
votes
2answers
110 views
Design, how to utilize The Hardware (multiple threads and/or GPU) while indexing (via a database) a very large set of binary files
Problem
How can design my file parser to maximize the hardware when processing (creating meta data for) a large file
(i.e. how to avoid being blocked by IO and running out of memory)
preferably ...
0
votes
2answers
58 views
Content delivery design
I'm designing a system where users can access files stored in an external content storage service such as AWS's S3. Here's a simple diagram:
------ ------------ -----------------
| User ...
2
votes
5answers
295 views
Why use a bool over more domain specific abstractions
Booleans are often used to model domain specific dichotomies. The most common example I can think of is the success or failure of an operation. It seems to me that a boolean must be interpreted in the ...
3
votes
1answer
79 views
Nested REST urls and parent id, which is better design?
Okay, we have two resources: Album and Song. Here is API:
GET,POST /albums
GET,POST /albums/:albumId
GET,POST /albums/:albumId/songs
GET,POST /albums/:albumId/songs/:songId
We know that we hate ...
3
votes
4answers
282 views
What architecture/design to adopt when consuming a RESTful API? (iOS App)
TL;DR
Part 1)
I want to refactor the biggest part of the app on which I work - and it is pretty much spaghetti. It's a single class that makes the requests to the server, parses the JSON and saves ...
0
votes
2answers
47 views
What are some ways to get application settings from users into class objects that also follow proper design principles? [closed]
I'm really confused how to enable the user to apply application settings for an application they are using (that get consumed by to a class object) AND the method I need to use to get the settings ...
4
votes
3answers
83 views
Sets of pair parameters
I have the following class, this class like many rely one parameters coming in as a pair.
Originally for convenience, I set them as params Object[] values and check if there is an even number of them ...
0
votes
0answers
26 views
Product Development Design - Customer specific changes [duplicate]
We are developing a web based product that will require customization for various customers.
Customers tend to have different rules and nomenclatures, hence the customization requirement.
The ...
1
vote
4answers
220 views
How to make one test depend on the results of another test?
Let's say there is a utility class that provides some common static methods used everywhere in your code by many other classes.
How would you design your unit tests for the consumers of the utility ...
1
vote
1answer
136 views
Problems with OO design for application with pluggable components
I'm trying to refactor an ugly code and make it easly extendable in the future.
The application should be nothing else but a series of components that have input(s) and output(s). The components ...
24
votes
6answers
3k views
When NOT to apply Dependency Inversion?
I am currently trying to figure out SOLID. So Dependency inversion means that any two classes should communicate via interfaces, not directly. E.g. if class A has a method, that expects a pointer to ...
0
votes
0answers
49 views
Should all public API POCO value-type properties be nullables?
I use nullable value types a lot when designing classes that have properties which may remain null, i.e. when the object is being persisted. For example:
public int? MyProperty { get; set; }
My ...
0
votes
2answers
107 views
Should a “secret access code” use the same security as a normal password? [closed]
Obviously, when you store a password, you should use something similar to bcrypt before you store it in in the database.
But I have a client who wants to add the ability to add a "secret code" to ...
2
votes
1answer
112 views
Many small requests vs. few large requests (API Design)
I'm currently working on a project with an organization as follows:
Client - Gets data from the main server via REST api.
Server - Requests data from various other servers via third-party APIs
...
2
votes
2answers
85 views
Free Standing Functions in Global Namespace
When writing non-member, free functions, can they be placed in the global namespace so long as the signature specifies a namespace-scoped object? For example, in the code below, is "Example 2" ...
0
votes
0answers
23 views
How to implement a Web UI feature to insert default scentences in an textarea [migrated]
We are talking about implementing a system that easily generates sales reports for our salesemployees. We want to create a webapplication with one or maybe more textarea's to gather the inputdata from ...
30
votes
10answers
6k views
Is it reasonable to assume that any physical quantity can be represented by a 64-bit integer without overflow or underflow?
The original binary search algorithm in the JDK used 32-bit integers and had an overflow bug if (low + high) > INT_MAX ...
1
vote
2answers
100 views
Caveats of using String.hashCode() on a switch on java < 1.7
There are several cases when I want to switch over a String input. I decided for implementing something like:
public Object doStuff(String param) {
switch (param.hashCode()) {
case 1234546:
...
2
votes
5answers
260 views
Is it bad or good to wrap mutable objects in immutable containers?
If I have parts of code that need to mutate the underlying data structure but then others that consume, not mutate the structure, is it good practice to create a wrapper which does not expose mutation ...
1
vote
2answers
90 views
How is a dictionary better than a big switch, when mapping data to action? [duplicate]
Often times we see stuff like that in code:
void myFunction(string someValue) {
if (someValue == "a") {
// ...
} else if (someValue == "b") {
// ...
} else if (someValue == ...
0
votes
1answer
37 views
Separate Drawable objects and their Data
I am looking for a way to design my application. Suppose you had a car drawing thing. Car has multiple parts.Some are going to be visible some are not.For example battery should be drawn. So someone ...
2
votes
1answer
57 views
timed events to modulation of real-time audio
I am new very to audio programming and am having trouble figuring out the right kind of algorithm for converting control events (e.g. like MIDI) to real-time sound genesis with a buffer.
At the ...
1
vote
2answers
38 views
Performing data operations that involve separate applications and data sources
I'm designing an enterprise application that produces output based on some input data from another application. In this case, I happen to have also built and thus do control the source application ...
4
votes
1answer
193 views
Should I avoid data duplication?
I'm trying to design a relatively simple ERP system. However, there are some requirements that complicate things a little bit:
It must be possible to add all sorts of contacts to the people table, ...
2
votes
2answers
91 views
Typedefs to convey relations between classes
I'm wondering if the following use of typedefs is any good practice, or if there are any downsides to it.
Basically I have alot of "data"-structs, which are intended to be used in (globally unique) ...
0
votes
1answer
146 views
Would adding more digits be a way to scale a order generation service? [closed]
I am working on interview questions from Amazon.com Software Development Engineer Intern Interview Questions.
One of the interviewees was asked "give a scalable system design of Amazon.com's order ...
