python 59 lines · 10 steps

Building a paginated JSON API with Flask MethodView

A class-based Flask view exposes a collection endpoint that lists articles with pagination links and creates new ones.

Explained by highlit

Flask Intermediate rest-api pagination class-based-views serialization blueprints

1from flask import Blueprint, request, url_for, jsonify, abort
2from flask.views import MethodView
3 
4from .models import Article, db
5from .schemas import ArticleSchema
6 
7articles_bp = Blueprint("articles", __name__, url_prefix="/api/articles")
8article_schema = ArticleSchema()
9 
10 
11class ArticleListAPI(MethodView):
12    init_every_request = False
13 
14    def get(self):
15        page = request.args.get("page", 1, type=int)
16        per_page = min(request.args.get("per_page", 20, type=int), 100)
17 
18        query = Article.query.order_by(Article.published_at.desc())
19        if author := request.args.get("author"):
20            query = query.filter_by(author=author)
21 
22        pagination = query.paginate(page=page, per_page=per_page, error_out=False)
23 
24        def page_url(p):
25            return url_for("articles.list", page=p, per_page=per_page, _external=True)
26 
27        return jsonify({
28            "data": article_schema.dump(pagination.items, many=True),
29            "meta": {
30                "page": pagination.page,
31                "per_page": pagination.per_page,
32                "total": pagination.total,
33                "pages": pagination.pages,
34            },
35            "links": {
36                "self": page_url(page),
37                "next": page_url(pagination.next_num) if pagination.has_next else None,
38                "prev": page_url(pagination.prev_num) if pagination.has_prev else None,
39            },
40        })
41 
42    def post(self):
43        errors = article_schema.validate(request.get_json() or {})
44        if errors:
45            abort(422, description=errors)
46 
47        article = article_schema.load(request.get_json())
48        db.session.add(article)
49        db.session.commit()
50 
51        response = jsonify(article_schema.dump(article))
52        response.status_code = 201
53        response.headers["Location"] = url_for(
54            "articles.detail", article_id=article.id, _external=True
55        )
56        return response
57 
58 
59articles_bp.add_url_rule("/", view_func=ArticleListAPI.as_view("list"))

01 / 01

STEP 01

Walkthrough

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Three takeaways

1Class-based MethodView maps HTTP verbs to methods, keeping list and create logic on one endpoint.
2Building hypermedia links from url_for keeps pagination self-describing and decoupled from URL structure.
3Validate before load and return 201 with a Location header to follow REST conventions for resource creation.

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