Implement Article Model, CRUD Routes, Decorators and Schemas - Issue #7

Author: anuragunni

api/backend/__init__.py

@@ -27,8 +27,10 @@
 from ..backend.home.routes import home_bp
 from ..backend.meta.routes import meta_bp
 from ..backend.users.routes import user_bp
+from ..backend.articles.routes import articles_bp
 
 app.register_blueprint(authentication_bp)
 app.register_blueprint(home_bp)
 app.register_blueprint(meta_bp)
 app.register_blueprint(user_bp)
+app.register_blueprint(articles_bp)

api/backend/articles/decorators.py

@@ -0,0 +1,53 @@
+from ..articles.schemas import article_form_schema
+from functools import wraps
+from flask import request
+from ..models import Article
+
+
+# Decorator to check if the article exists
+def article_exists(f):
+    @wraps(f)
+    def wrap(*args, **kwargs):
+        article = Article.query.get(kwargs["article_id"])
+
+        if article:
+            return f(*args, **kwargs)
+        else:
+            return {
+                       "message": "Article does not exist"
+                   }, 404
+
+    return wrap
+
+
+# Decorator to check if a article form data is valid
+def valid_article_form(f):
+    @wraps(f)
+    def wrap(*args, **kwargs):
+        form_data = request.get_json()
+        errors = article_form_schema.validate(form_data)
+
+        # If form data is not validated by the article_form_schema, then return a 500 error
+        # else create the article and add it to the database
+        if errors:
+            return {
+                       "message": "Missing or sending incorrect data to create a article. Double check the JSON data that it has everything needed to create a classroom."
+                   }, 422
+        else:
+            return f(*args, **kwargs)
+
+    return wrap
+
+
+# Decorator to check if the Article table has articles before printing upto 15 articles
+def article_table_empty(f):
+    @wraps(f)
+    def wrap(*args, **kwargs):
+        if Article.query.first():
+            return f(*args, **kwargs)
+        else:
+            return {
+                       "message": "No articles present"
+                   }, 404
+
+    return wrap

api/backend/articles/routes.py

@@ -0,0 +1,67 @@
+from .. import api, db
+from ..articles.decorators import article_exists, valid_article_form, article_table_empty
+from ..articles.utils import create_article, update_article
+from ..articles.schemas import article_schema, articles_schema 
+from flask import Blueprint, request
+from flask_restful import Resource
+from ..models import Article
+
+# Blueprint for articles
+articles_bp = Blueprint("articles", __name__)
+
+
+# Class to handle information regarding the Article model
+class Articles(Resource):
+    
+    # Function to create an article
+    @valid_article_form
+    def post(self):
+        form_data = request.get_json()
+        article = create_article(form_data)
+
+        db.session.add(article)
+        db.session.commit()
+
+        return {"message": "Successfully created Article"}, 201
+
+    # Function to display all the articles up to a limit of 15 
+    @article_table_empty
+    def get(self):
+        article = Article.query.limit(15)
+        return articles_schema.dump(article, default=str)
+
+
+class ArticleCRUD(Resource):
+
+    # Function to edit an article 
+    @valid_article_form
+    @article_exists
+    def put(self, article_id):
+        article = Article.query.get(article_id)
+        form_data = request.get_json()
+        update_article(article, form_data)
+
+        db.session.commit()
+
+        return {"message": "Article successfully updated"}, 200
+
+    # Function to delete an article 
+    @article_exists
+    def delete(self, article_id):
+        article = Article.query.get(article_id)
+        
+        db.session.delete(article)
+        db.session.commit()
+
+        return {"message": "Article successfully deleted"}, 200
+
+    # Function to display an article 
+    @article_exists
+    def get(self, article_id):
+        article = Article.query.get(article_id)
+
+        return article_schema.dump(article)
+
+# Creates the routes for the classes
+api.add_resource(Articles, "/api/articles")
+api.add_resource(ArticleCRUD, "/api/articles/<int:article_id>")

api/backend/articles/schemas.py

@@ -0,0 +1,26 @@
+from marshmallow import Schema, fields
+import toastedmarshmallow
+
+# This schema is used to display article data
+class ArticleFormSchema(Schema):
+    title = fields.Str(required=True)
+    cover_image = fields.Str(required=False)
+    content = fields.Str(required=False)
+
+
+# This schema is used to display article data
+class ArticleSchema(Schema):
+    id = fields.Int(required=True)
+
+    class Meta:
+        # Fields to show when sending data
+        fields = ("id",)
+        ordered = True
+
+
+article_form_schema = ArticleFormSchema()
+article_schema = ArticleSchema()
+articles_schema = ArticleSchema(many=True)
+article_form_schema.jit = toastedmarshmallow.Jit
+article_schema.jit = toastedmarshmallow.Jit
+articles_schema.jit = toastedmarshmallow.Jit

api/backend/articles/utils.py

@@ -0,0 +1,20 @@
+from ..models import Article
+
+
+# Function to create an article
+def create_article(form_data):
+    article = Article(title=form_data["title"],
+                          cover_image=form_data["cover_image"],
+                          content=form_data["content"]                        
+                          )
+
+    return article
+
+
+# Function to update an article
+def update_article(article, form_data):
+    article.title = form_data["title"]
+    article.cover_image = form_data["cover_image"]
+    article.content = form_data["content"]
+
+    return

api/backend/models.py

@@ -1,4 +1,5 @@
 from api.backend import db
+import datetime
 
 
 class Meta(db.Model):
@@ -54,3 +55,16 @@ class Teacher(db.Model):
 
     def __repr__(self):
         return f"Teacher('{self.id}')"
+
+
+class Article(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    title = db.Column(db.Text, nullable=False)
+    cover_image = db.Column(db.Text, nullable=True)
+    content = db.Column(db.Text, nullable=False)
+    date_published = db.Column(db.DateTime, nullable=False, default=datetime.date.today)
+    likes = db.Column(db.Integer, nullable=False, default=0)
+    is_published = db.Column(db.Boolean, nullable=False, default=True)
+
+    def __repr__(self):
+        return f"Article('{self.id}')"