Jeg genopbyggede den samme web-API ved hjælp af Express, Flask og ASP.NET. Her er hvad jeg fandt.

Jeg har shoppet rundt efter en backend-ramme for at understøtte en bordpladespil-app og besluttede at undersøge noget for at finde den bedste pasform til mine behov.

Målet var ligetil: at opbygge en simpel RESTful API, der gør det muligt for en frontend-app at udføre grundlæggende CRUD-operationer, hvilket giver mig en introduktion til, hvordan udviklingsprocessen ser ud.

Der er mange backend-rammemuligheder derude, og jeg er mest fortrolig med JavaScript, C # og Python (i den rækkefølge), hvilket begrænsede mine muligheder noget. Det naturlige udgangspunkt var at opbygge en simpel frontend, der ville sende anmodninger til en API, som igen ville læse fra og skrive til en lokal database.

Jeg begyndte min udviklingsproces med Express, som af grunde, som jeg snart vil forklare, fik mig til også at tjekke Flask og ASP.NET. Jeg troede, at mine fund kunne vise sig nyttige for andre derude, der forsker i backend-rammer for små projekter. I denne artikel giver jeg også kodeeksempler og de ressourcer, jeg brugte til at bygge alt.

Du kan også få adgang til den fulde kode på GitHub.

Jeg skal forbeholde mig, at jeg ikke promoverer en ramme frem for en anden og endnu ikke har sammenlignet ting som implementering, godkendelse eller skalerbarhed. Din kilometertal kan variere, hvis disse oplysninger er vigtige for dig!

Jeg vil dog give en TL; DR i bunden, hvis du bare vil få en oversigt og nøgleindlæringer.

Nu sker det!

Definition af API

Hvis du er ny inden for webudvikling, spørger du muligvis "hvad er en API?"

Jeg har måttet stille spørgsmålet hundrede gange for at finde et svar, der giver mening. Og det var først, da jeg byggede min egen, at jeg kunne sige, at jeg forstod, hvad en API gør .

Kort sagt, en API eller "applikationsprogrammeringsgrænseflade" gør det muligt for to forskellige computersystemer at tale med hinanden. I denne artikel viser jeg en simpel frontend-app, der viser en "quest" tracker, som spillerne kan se til deres bordplade-rollespil. Hver quest har et "navn" og en "beskrivelse", som begge vises i webbrowseren.

Hvis jeg allerede havde alle de quests, der er anført på webstedet, og bare ville have, at spillerne skulle se dem, ville jeg ikke have brug for en API eller back-end. Til dette projekt vil jeg dog have muligheden for at give brugerne mulighed for at tilføje quests, søge efter dem, slette dem osv. Til disse operationer er jeg nødt til at gemme quests et eller andet sted, men min frontend-app er ikke i stand til at overføre oplysninger direkte til en database.

Til det har jeg brug for en API, der kan modtage HTTP-anmodninger fra webstedet, finde ud af, hvad de skal gøre med disse anmodninger, interagere med min database og sende mere information tilbage i kæden, så brugeren kan se, hvad der skete.

Det hele - frontend-"klienten", back-enden "API" eller serveren og databasen - kaldes en "stak" eller mere præcist "fuld stak". Til dette projekt byggede jeg et simpelt frontend-websted som toppen af ​​stakken og slukkede alt under det, da jeg prøvede forskellige rammer og databaser.

Projektstruktur

Strukturen til dette projekt var ret enkel, med frontendklienten adskilt fra tre forskellige servere, som jeg ville spinde op efter behov for at betjene API'en.

Jeg brugte Visual Studio Community som min kodeditor og IDE med de nødvendige sprogpakker installeret til JavaScript, Python og C #.

Jeg giver et overblik over min erfaring med hver ramme efter tur med links til de selvstudier og pakker, som jeg brugte til at få dem til at arbejde sammen med klienten. Men lad os først se på frontenden!

Kunden: Vue.js

Målet for klienten var at have et simpelt websted, der ville modtage information fra databasen via API'en og vise dem for brugeren. For at strømline processen var mine krav, at klienten kun behøvede at "læse" alle elementerne i databasen og give brugeren mulighed for at "oprette" en ny quest.  

Disse "læse" og "oprette" operationer - "R" og "C" i "CRUD" - er analoge med HTTP-metoderne i "GET" og "POST", som vi ser i koden nedenfor.

I udviklingen af ​​frontend er jeg mest fortrolig med at bruge Vue og brugte Vue CLI til at stilladsere en grundlæggende klient med følgende filstruktur:  

Jeg udskiftede kedelplademarkeringen fra Vue CLI med følgende:

RPG Quests

{{quest.name}}: {{quest.description}}

Add Quest

Og den tilsvarende Vue-kode:

import axios from 'axios'; export default { name: 'App', data: function () { return { quests: null, newQuestName: null, newQuestDescription: null } }, methods: { getQuests: function () { axios .get('//localhost:3000/quests') .then(response => (this.quests = response.data)); }, addQuest: function () { axios .post('//localhost:3000/quests', { name: this.newQuestName, description: this.newQuestDescription }); }, postQuest: function () { axios.all([this.addQuest(), this.getQuests()]); this.$forceUpdate(); } }, mounted: function () { this.getQuests(); } }

Hvis du ikke er bekendt med Vue, er detaljerne i frontenden ikke så vigtige! Af betydning her er, at jeg bruger en JavaScript-pakke kaldet Axios til at stille mine GET- og POST-anmodninger til en potentiel server.

Når klienten indlæses, sender den en GET-anmodning til URL // localhost: 3000 / quests for at indlæse alle quests fra databasen. Det giver også et par inputfelter og en knap, der vil POSTE en ny quest.

Brug af Vue CLI til at betjene klienten på // localhost: 8080, den forreste ende af appen ser sådan ud i aktion:

Once quests are added to the database, they'll start appearing in between the "RPG Quests" header and the input fields.

Client Resources

To build the client, I used:

  • NodeJS/NPM for package management
  • Vue CLI for scaffolding, serving, and building projects
  • Axios for making HTTP requests to the API
  • Vue Axios Documentation for making sense of how to use Axios in concert with the API
  • Postman for testing API requests through the browser before implementing them in the client.

JavaScript API: Express

Express is a lightweight web framework for NodeJS that allows you to write server-side applications with JavaScript.

It's un-opinionated, which means that you can build your applications how you like without it defining the architecture for you. You can add packages to improve functionality as you fancy, which I found to be a double-edged sword as a newbie to the framework. More on that later.

Being most comfortable in JavaScript, I was excited by the prospect of having the entire stack run on just one language instead of several. I had heard of the "MEVN Stack," which denotes a full stack application that is comprised of MongoDB, Express, Vue, and NodeJS, and decided to try that out for this iteration of the project.

I followed a web API tutorial to first build a template app, then used another MEVN tutorial to fill in the details of how to get the API to communicate with the Vue client that I had built. The Express API that I created for this project follows a similar structure to the former, using MongoDB as the database:

If you're coming from a JavaScript background, Express is fairly easy to read, even if you're not familiar with some of the back end terminology. The following is a snippet from /routes/quests.js, for example, which handles the HTTP endpoint requests:

router.get('/', async (req, res) => { try { const quests = await Quest.find(); res.json(quests); } catch (err) { res.status(500).json({ message: err.message }); } }); router.post('/', async (req, res) => { const quest = new Quest({ name: req.body.name, description: req.body.description }); try { const newQuest = await quest.save(); res.status(201).json(newQuest); } catch (err) { res.status(400).json({ message: err.message }); } });

The general theme of the code is to receive a request, attempt to contact the database to do work, and then send a response back to whoever's asking. The specifics can be quite complex, particularly if you're writing your own middleware that does things in between the request and response, but the code is at least readable.

I found MongoDB to be painless to work with as a NoSQL database.  If you're working with Express, you'll most likely use Mongoose as an ODM - basically like a "middle person" that translates a model of what your data looks like to the database.

The model in this app (called a "schema" in Mongoose terms) is really simple, located in /models/quests.js:

const questSchema = new mongoose.Schema({ name: { type: String, required: true }, description: { type: String, required: true } });

The above indicates that the database should store our two fields: a quest name and a quest description.  Both of these fields are strings, and required. All GET and POST requests will have to conform to this model to interact with the database.

After wiring all of this up and POSTing a few new quests, the front end site started populating with data:

The process of setting up the Express API was not without its hair pulling, however. Being a primarily front end and 2D game developer, I've become intimately familiar with how dispersed the JavaScript ecosystem can feel. This frustration was magnified in attempting to build a back end app. There are a lot of packages required to get everything up and running, each of which having its own required configuration and implementation.

If you're looking for a framework that just does everything out of the box, Express is most certainly not the choice for you. It's lightweight, flexible, and easy to read, in a very "choose-your-own-adventure" fashion. I quite like how clean the code is and the ability to structure my projects as I see fit, but troubleshooting and error handling do leave a lot to be desired.

JavaScript/Express Resources

To build the JavaScript API, I used:

  • NodeJS/NPM for package management
  • Express as the main web framework
  • Dotenv to create environment-specific variables
  • Nodemon to watch files for changes and restart the server so I didn't have to
  • CORS to allow for cross-origin requests (basically a pain if you're trying to make requests from a client to a server that are both running locally on your machine)
  • MongoDB for the NoSQL database
  • Mongoose for writing models that map onto MongoDB
  • This API tutorial to provide a basic understanding of how to create an Express-MongoDB stack
  • This MEVN tutorial to fill in the gaps of running a MongoDB-Express-Vue-Node full stack

Python API: Flask

In the process of building the Express API, I had a conversation with a data science friend who works in Python. This gave me the idea of trying out non-JavaScript frameworks to see if they were better suited for my app.

I took a cursory look at Django, since I'd been hearing about it as a powerhouse back end framework that provides everything out of the box. I was a little intimidated by how opinionated it seemed, and opted to try out Flask instead, which kind of felt like the Python equivalent of Express.

I followed the first few bits of the excellent Flask Mega-Tutorial to get my app structure set up, using the companion RESTful API tutorial to fill in the pieces of HTTP requests. The file structure turned out to be only a shade more complex than that of the Express API:

The tutorial I followed uses SQLite for its database, with Flask-SQLAlchemy as an ORM. The HTTP request code that's most analogous to the Express API is located in /app/routes.py:

@app.route('/quests', methods=['GET']) def get_quests(): questQuery = Quest.query.all() quests = {} for quest in questQuery: quests[quest.name] = quest.description return jsonify(quests) @app.route('/quests', methods=['POST']) def post_quest(): newQuest = Quest(name=request.json['name'], description=request.json['description']) db.session.add(newQuest) db.session.commit() return "Quest Added!"

Similarly, the database model (akin to the Mongoose "schema") is in /app/models.py:

class Quest(db.Model): name = db.Column(db.String(256), primary_key=True, index=True, unique=True) description = db.Column(db.String(256), index=True, unique=True)

As I mentioned, I'm more familiar with JavaScript and C# than with Python, and working with the latter to build the Flask API felt like cheating. Certain things like pathing, package handling, and writing workable code were just easy, although I did get hung up on getting the API to correctly parse JSON for the client. I suspect that was more of an issue of my unfamiliarity with the language than anything else, but it did take time to troubleshoot.

To be quite honest, coming from a non-Flask background, I did kind of expect to complete a couple of tutorials and spin up an API without having to do all that much work for it.  

I can't say that it turned out that way, as Python does have its own particulars that require some time to get used to. Still, the Python ecosystem appears to be extremely well organized, and I enjoyed my time building the Flask API.

I've also heard that Django is a better and more scalable option for larger projects. But it seems like it would involve a separate, and steeper, learning curve to become proficient.

Flask was easy enough for me as a non-Python developer to pick up and build something over a weekend. I suspect that learning Django would take quite a bit longer, but with potentially greater dividends over the long run.

Python/Flask Resources

To build the Flask API, I used:

  • Python 3/pip for package management
  • Flask as the main web framework
  • python-dotenv to configure environment variables
  • SQLite as the database
  • Flask-SQLAlchemy as the ORM to work with SQLite
  • Flask-Migrate as an additional tool to migrate data to SQLite
  • Flask-CORS to handle the same CORS issue as with the Express API
  • The Flask Mega-Tutorial to learn the basics
  • The Flask REST API tutorial to understand how to receive HTTP requests

C# API: ASP.NET

I can't tell you how many times I've Googled ".NET" to understand what it is, how it's different from ASP.NET, and why I'd want to use any of it. My C# knowledge comes mainly from working with Unity, which exists somewhat adjacent to .NET and doesn't provide for a lot of exposure to Microsoft's larger ecosystem.

I've spent some time researching Razor Pages and MVC, and finally came to understand ASP.NET's breadth of features as Microsoft's open source web framework. I decided to toss ASP.NET into the hat for a potential back end for my app, and set about working through the official web API tutorial with ASP.NET Core and MongoDB.

The file structure for this version of the API was more complex than the others, given that .NET projects tend to have a much larger footprint:

I should also mention that I already had Visual Studio and all of the required workloads installed, which made the setup process easier. Plus, having spent time with MongoDB for the Express API, I found the database portion of the project to be similar, although by default, ASP.NET seems to prefer using Microsoft's SQL Server and the Entity Framework ORM.

The ASP.NET code for HTTP requests is a bit more complex than what we've seen with the two other APIs, but it's no match for all of the code that sits around it.  

First, consider this snippet in /Controllers/QuestController.cs that handles requests:

namespace QuestAPI.Controllers { [Route("quests/")] [ApiController] public class QuestsController : ControllerBase { private readonly QuestService _questService; public QuestsController(QuestService questService) { _questService = questService; } [HttpGet] public ActionResult
    
      Get() => _questService.Get(); [HttpPost] public ActionResult Create(Quest quest) { _questService.Create(quest); return CreatedAtRoute("GetQuest", new { id = quest.Id.ToString() }, quest); } } }
    

Not too terrible, almost kind of readable, in a C# sort of way. The data model in /Models/Quest.cs is even easier:

namespace QuestAPI.Models{ public class Quest { [BsonId] [BsonRepresentation(BsonType.ObjectId)] public string Id { get; set; } [BsonElement("Name")] public string Name { get; set; } public string Description { get; set; } } }

These two snippets essentially do the same things as the previous examples that we've seen: take requests from the front end, process them to get or modify data in the database, and send a response back to the client.  

Yet, as you can probably tell from the complex file structure, there's so much code that surrounds these snippets, along with Interfaces, Dependency Injection, and other abstractions, that it can be challenging to understand how it all works together.

Consider the following configuration code in /Startup.cs:

 public void ConfigureServices(IServiceCollection services) { services.Configure(Configuration.GetSection(nameof(QuestDatabaseSettings))); services.AddSingleton(sp => sp.GetRequiredService
    
     ().Value); services.AddSingleton(); services.AddCors(options => { options.AddPolicy(MyAllowSpecificOrigins, builder => { builder.WithOrigins("//localhost:3000/quests", "//localhost:8080").AllowAnyHeader().AllowAnyMethod(); }); }); services.AddControllers(); }
    

Or this particularly nested bit from a separate SQL Server web API tutorial:

 [HttpGet] public async Task
    
     > GetTodoItems() { return await _context.TodoItems .Select(x => ItemToDTO(x)) .ToListAsync(); }
    

Lol. What?? As a new user, even familiar as I am with C#, I can go line-by-line to understand each abstraction, or I can just trust that the framework is handling everything for me and forget about it.

I tend to want to know exactly how my code works so that I can fix or alter it if necessary. But I certainly feel like my time spent learning the ins-and-outs of ASP.NET could be better utilized towards mastering another framework.

To be fair, ASP.NET appears to be similar to Django in being more opinionated and providing you with a ton of stuff out of the box, including an authentication solution, database management, and the lot. If these things are important to you, it's certainly worth considering.  

It also has the full support of Microsoft and an open source community. So if you're looking at developing enterprise-level applications that need to scale, you might want to take a longer look at ASP.NET as a potential solution.

C#/ASP.Net Resources

To build the ASP.Net API, I used the following resources:

  • Visual Studio Community as my code editor and IDE, with the ASP.NET and web development workload installed (I already had MongoDB running from the Express API)
  • Microsoft's official tutorial for building web APIs with ASP.NET and MongoDB

TL;DR

In all, with some slight variations and hiccups among them, I've gotten each of the web APIs to work with the Vue client, with the ability to view quests from and add quests to the database. Hopefully, my explanation of the process has been helpful in your own search for a back end framework, but here are some additional recommendations just in case:

  • If you're a JavaScript developer and/or want to manage everything that your application does, including its architecture, consider using Express.
  • If you're a Python developer and/or want a pleasant experience in developing small projects, try Flask, but consider using Django if you need more out-of-the-box support and don't mind conforming to an opinionated framework.
  • If you're a C# developer and willing to spend the time to learn the most arcane details of C# coding best practices, consider using ASP.NET. Alternatively, if you need enterprise-level support right out of the box, you'd be hard-pressed to find better.
  • If you don't know what to use and just want to learn back end development, take a look at Flask.  It's easy to work with and will teach you the basics that you'll need to know for building web apps in any coding language.
  • If you don't know what to use and want an adventure, choose Express. There's a rabbit hole of package management and Stack Overflow questions waiting that may make you tear your hair out, but you'll learn a lot about the JavaScript ecosystem and web development in general.

Additionally, two things bear mentioning that threw me for a spin in this process: CORS and environment variables. The former I've mentioned in this article a couple of times already, but it's worth discussing again to understand the scope of building a full stack app on your machine.

Unless you have an integrated development environment that's handling the whole stack for you, you'll likely have a client, a server, and a database that are all running independently of one another.  

In the Express API section above, for example, I was running

  1. the Vue CLI server, which rendered my front end app on port 8080;
  2. an NPM script to spin up the Express API server on port 3000; and
  3. a separate instance of the Mongo database to get everything working together. That's three command prompts open and a general mess!

If you dig into the Vue code above (or on GitHub), you'll see that the requests made on behalf of the client, running on //localhost:8080, are to the server on //localhost:3000, which is where the Express API is listening. This is called "cross-origin resource sharing," or CORS, and it's blocked by the browser for security concerns. Most frameworks require you to install an additional package to get the whole thing running in your local environment.

Second, you'll want to become comfortable with environment variables, which can really help smooth some rough pathing edges at runtime. I used dotenv and Flask-Env for the Express and Flask projects, respectively.

Both packages allow you to configure things like where your database lives, or what default port your application should be using, in one document. Your application then uses that document at runtime to figure out where to find everything, without any further configuration needed from you.

One final note that may be helpful if you're just working on a back end project and don't want to go through the trouble of building a front end client: consider using a third-party app like Postman. I used it to make HTTP requests to each of the APIs to make sure they were working properly before layering on the Vue client and trying to get the whole stack running altogether.

I hope this article has been helpful for you in your own process of looking for a back end framework.  Let me know what you find!

Hvis du kunne lide denne artikel, kan du overveje at tjekke mine spil og bøger, abonnere på min YouTube-kanal eller deltage i Entromancy Discord.

MS Farzan, Ph.D. har skrevet og arbejdet for højt profilerede videospilvirksomheder og redaktionelle websteder som Electronic Arts, Perfect World Entertainment, Modus Games og MMORPG.com og har fungeret som Community Manager for spil som Dungeons & Dragons Neverwinter og Mass Effect: Andromeda . Han er Creative Director og Lead Game Designer af Entromancy: A Cyberpunk Fantasy RPG og forfatter af The Nightpath Trilogy . Find MS Farzan på Twitter @sominator.