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2
votes
4answers
69 views

Keeping a ratio column that's the division between two other columns

I'm about to build a SQL table where I want to store currency orders. That means that I need to store how much I paid for a certain quantity, and the ratio between both quantities. So for example: ...
22
votes
4answers
30k views

Should angularjs directive directly interact with services or is it considered an anti-pattern?

Which one is considered better: having a directive that interacts with services directly or having a directive that exposes certain hooks to which controller may bind behaviour (involving ...
7
votes
4answers
336 views

Is there a Haskell idiom for trying several functions and stop as soon as one succeeds?

In Haskell, I can use the type a -> Maybe b to model a function that either returns a value of type b, or returns nothing (it fails). If I have types a1, ..., a(n+1) and functions f1, ..., fn, ...
0
votes
0answers
18 views

Relying on file hash for data synchronisation across mobile and server

Imagine a client-server app that lets user upload images/documents etc. to server and then lets users who have access, retrieve and view them later on their respective mobile devices. So the flow is ...
10
votes
8answers
778 views

Designs and practices to guard against erroneous null entries from database

One part of my program fetches data from many tables and columns in my database for processing. Some of the columns might be null, but in the current processing context that is an error. This should ...
4
votes
2answers
107 views

Should a RESTful API be able to return files, or just a location

This has been puzzling me for a while. For example, we have a REST API that provides basic content to a system, consuming and producing JSON. At this endpoint it produces a URL to a picture and a ...
2
votes
0answers
31 views

Should my application call statsd directly or should I call statsd based off logs?

I'm planning on incrementing counters in statsd based of various events within my application. I have logging in place for these events. So, from my viewpoint I have two options: Update the ...
8
votes
3answers
2k views

When is Efferent / Afferent coupling good or bad

I have a software patterns exam this week and one of the topics we are to study is Efferent and Afferent coupling. I understand a package has a high Ce (efferent coupling) if it depends on a number ...
1
vote
2answers
2k views

How to implement a hybrid role-based access control model?

I am writing an enterprise web-forms-frontend application for in-house use. It has Direct access control (DAC) masquerading as Role-based access control (RBAC). For anonymization purposes, let's ...
0
votes
1answer
45 views

Reusing array with static test data across test classes

I have a Map which takes in an a String key, and an array of custom objects as the value. the map usually contains two entries, and the arrays for both entries never change in terms of data; once they ...
5
votes
5answers
460 views

Advantages of Strategy Pattern

Why is it beneficial to use the strategy pattern if you can just write your code in if/then cases? For example: I have a taxPayer class, and one of its methods calculates the taxes using different ...
1
vote
3answers
172 views

CRUD operations in DDD

I'm designing an application with DDD. I'm moving from flat POCO objects to strong domain models, so my question is: Would I have to call my basic CRUD operations (located in my repository layer) ...
4
votes
1answer
340 views

How to make sure people call methods in the right order?

Situation I'm designing a database abstraction layer for sql (mysql, sqlite) and mongoDb. The goal is to give the user/developer a library which is able to create queries for different databases. ...
1
vote
1answer
443 views

JSP in Javascript file or multiple AJAX requests

I've been thinking about how I want to load my data for some checkboxes in an AngularJS app. I'm generating multiple checkboxes based on 2 JSON objects that are currenty hard-coded in the a Javascript ...
0
votes
1answer
183 views

MVC Best practice mixing Partial View and JavaScript

I searched the internet and really can't find a good answer to this question. Imagine there is a View that contains a simple tab-element. Each tab-content is loaded dynamically (via ajax) when the ...
1
vote
2answers
92 views

Explaining concepts [closed]

How can I explain a concept when I don't know its name or any formal reason for it? The reason I ask is this... A new programmer has entities with a property title in his system. He uses the title to ...
6
votes
1answer
831 views

Which patterns/architecture to apply for “Import Data, Process Data, Export Result”

I was wondering which architecture/patterns to choose for the following problem divided into three steps: Import TestScript Description from File (e.g. .xls, .txt) Process Described TestScript ...
1
vote
0answers
73 views

Algorithm for evaluating line breaks efficiently [closed]

Consider following problem : Given: String input with the length n Font(-metrics) - potentially slow in usage Bounds of an abstract Textview which shall contain the text in a specific manner: e.g ...
2
votes
1answer
537 views

prism and multiple screens

OK - I am studying Prism a little because of a "free weekend" offer on Pluralsight. As this is proving too complex for me, I went to the Prism book and looked at the forward, and this is what it said: ...
1
vote
1answer
52 views

Name pattern for quickly find descendents with SQL (PATH column with [TopId]…[DirectAncestorId].[OwnId]) NO nested sets

I read a long time ago about a pattern/technique for easily querying for all "descendants" of a record (no need to use CONNECT TO, which is not standard and not available with JPA). I remembered the ...
1
vote
1answer
89 views

Pattern for passing in a field as a parameter

I'm writing a Rails app which uses ActiveRecord ORM and a Postgres DB. I've got two attributes which are similar but are separate fields in the database. The assignment and saving of these is kinda ...
3
votes
4answers
428 views

Where to store average value in db?

I have a restaurant review app which stores reviews in a db, MySql. There's 2 tables. 1 for Restaurant. Another for reviews. To increase the performance, I am considering to store the avg review of ...
1
vote
2answers
267 views

Is there a name for this pattern?

A while loop can be written as follows in C# (and many other languages): int someValue; int someTerminatingValue; while ((someValue = GetSomeValue()) != someTerminatingValue) { // Do something ...
66
votes
2answers
8k views

Are there any OO-principles that are practically applicable for Javascript?

Javascript is a prototype-based object oriented language but can become class-based in a variety of ways, either by: Writing the functions to be used as classes by yourself Use a nifty class system ...
1
vote
1answer
455 views

What is the “Find-Fix-Verify” pattern? [closed]

What is the "Find-Fix-Verify" pattern, as related to the process of doing editing/spellchecking/debugging, etc.? Where is this pattern best described? What are some advantages and disadvantages of ...
9
votes
4answers
532 views

Reducing boilerplate in class that implements interfaces through composition

I have a class: A that is a composite of a number of smaller classes, B, Cand D. B, C, and D implement interfaces IB, IC, and ID respectively. Since A supports all the functionality of B, C and D, A ...
1
vote
2answers
252 views

Joshua Bloch Enum Singleton and Third Party APIs

In the book Effective Java he give the best Singleton pattern implementation in his, that is implement by a Enum. I have doubt to how to implement this pattern with a third party API. I'm using an ...
2
votes
2answers
167 views

Does it break SRP to have concerns of data handling and object mapping inside a single class, as part of the DataMapper pattern?

Summary I want to look into separating the concern of "creating a populated object from database", to use inside my application. DataMapper pattern seems to be doing just that for me. DataMapper ...
3
votes
4answers
282 views

Function wrappers with no args: bad practice?

My colleague likes to write classes containing methods looking like this: public function doTaskA() { return $this->doTask('A'); } public function doTaskB() { return $this->doTask('B'); ...
1
vote
2answers
625 views

Are the Repository Pattern and Active Record pattern compatible?

Currently I am developing a webapp where I have defined models implementing the Active Record pattern. Each model also is defined by an interface that specifies the Entity properties and makes it easy ...
1
vote
2answers
193 views

Is it a good idea to install more libraries than you need? [closed]

I decided to try Anaconda, it seems that too many large companies are using it. I was amazed by the number of libraries included by default installing: python-2.7.9-2 ... installing: ...
12
votes
5answers
2k views

How to migrate my thinking from C++ to C#

I am an experienced C++ developer, I know the language in great details and have used some of its specific features intensively. Also, I know principles of OOD and design patterns. I am now learning ...
-1
votes
1answer
138 views

Best solution for future maintenance of a website with hardcoded ids, custom CMS using bad database design [duplicate]

Recently I was put into a position of a tech-lead on a very interesting project that I have been partially working for two years. This project carries a lot of legacy stuff with it even though we try ...
3
votes
2answers
165 views

Is it OK for an MVC view to request data from other sources than just the model?

I'm working in ASP.NET MVC, but this question is pretty much applicable to any MVC framework (and maybe even others). In a typical MVC application a request arrives at the controller, which then ...
7
votes
1answer
357 views

Should I build undo stack in model or its wrapper?

I am building an application (Python/PyQt). The first-order item will be a tree view/model with many helper functions to add new items, move them around in the tree, etc.. Then I will have a main ...
2
votes
1answer
55 views

Queue rescheduling naming convention (Command pattern)

For my project I'm creating a queueing mechanism based on the Command Pattern, which can execute one of a number of jobs. Jobs can add other jobs to the queue or can be added by a human. Most of the ...
5
votes
3answers
475 views

How to solve the Lava flow anti-pattern?

In this blog post, the author describes an anti-pattern called the "lava flow" In a nutshell, the lava flow anti-pattern happens when many programmers lead the development of an application, each of ...
2
votes
1answer
401 views

Design patterns to avoiding breaking the SRP while performing heavy data logging

A class that performs both computations and data logging* seems to have at least two responsibilities. Given a system for which the specifications require heavy data logging, what kind of design ...
0
votes
4answers
296 views

2 methods that are 75% the same? [closed]

I have code that violates the DRY principle and I would like to consolidate 2 methods as much as I can, but the problem I am facing is that they have some differences, I would say they are about 75% ...
32
votes
5answers
6k views

Is “convention over configuration” not violating basic programming principles?

I was looking at the WPF MVVM framework Caliburn.Micro and read that a lot of standard things are based on naming conventions. For example, automatic binding of properties in the View to properties ...
5
votes
1answer
203 views

Is it poor decision making that using promises for GUI inputs?

So as you know the context: DOM with JavaScript, even though I think it is mostly a language agnostic issue (I know I put both language-agnostic and JavaScript tags, but it's only to let you see ...
22
votes
12answers
6k views

What design patterns are the worst or most narrowly defined? [closed]

For every programming project, managers with past programming experience try to shine when they recommend some design patterns for your project. I like design patterns when they make sense or if you ...
0
votes
1answer
142 views

Why use the Singleton pattern over class functions and fields? [duplicate]

I'm going to start by saying that I understand that programming in mostly class functions and variables can be harmful to object-orientation, and that most of the time an instance is preferred. I'll ...
2
votes
5answers
683 views

I have generally read that having many (>4) arguments to a function/constructor is a bad practice. Is this still considered a bad practice? [closed]

I have generally read that having many (>4) arguments to a function/constructor is a bad practice. Is this still considered a bad practice? And is there a non-obvious reason? In something like a ...
0
votes
3answers
243 views

Check a boolean before setting it in a loop, or just set it

I have a rather tight loop with the following check to see if balance had ever been positive: balance_null = True while (crazy_loop()): ... if 0.0 < balance: balance_null = False ...
2
votes
1answer
102 views

Combining Patterns: Fluent Builder and Null Object Pattern

I am currently wrestling around with some GUI code where I have a table whose rows correspond to some object, let's say a Person object. When the table initializes, it fills the table with the Person ...
2
votes
3answers
1k views

How to implement the repository pattern for an app that will change its database from sql to nosql on in couple of years?

I have been reading a lot about repository implementation. I am confused about which way to implement it for a project I am sure would change its data layer methods because of db migration from MS Sql ...
3
votes
3answers
2k views

Why is it a good practice to keep Javascript code in separate files?

In web development we are commonly used to keep Javascript code in separate files, but sometimes we need this Javascript code to manipulate server side data locally. For example, making an Ajax Call ...
4
votes
2answers
125 views

Factors for choosing between using a wrapper library or issuing command line process from my web application

I have a Java web application that makes use of certain libraries for example: Ghost Script for converting PDFs to TIFFs and Tesseract for OCR. There are java wrappers for both of these: Ghost4J and ...
4
votes
2answers
104 views

Is it a good idea to have a database row that represents an unknown value within a system [closed]

We have two systems, System A imports a list of sports events from system B, it only wants to import the events we will be providing live data for, the filter used to hide events that we are not ...