# Flask Marshmallow

***

**1. Basic Serialization:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(required=True)
    email = ma.String(required=True)

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**2. Nested Serialization:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class OrderSchema(ma.Schema):
    items = ma.Nested(ItemSchema, many=True)

order_schema = OrderSchema()
order_dict = order_schema.dump(order)
```

**3. Filtering by Schema:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(required=True)
    email = ma.String(required=True)

    class Meta:
        exclude = ('password',)

user_schema = UserSchema()
filtered_user_dict = user_schema.dump(user)
```

**4. Complex Filtering by Schema:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(required=True)
    email = ma.String(required=True)

    class Meta:
        fields = ('id', 'name', 'email')
        additional = ('first_name', 'last_name')

user_schema = UserSchema()
filtered_user_dict = user_schema.dump(user)
```

**5. Limiting Depth of Nested Serialization:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class OrderSchema(ma.Schema):
    items = ma.Nested(ItemSchema, depth=1)

order_schema = OrderSchema()
order_dict = order_schema.dump(order)
```

**6. Automating Serialization:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class User(ma.Model):
    name = ma.String()
    email = ma.String()

user = User()
user_dict = user.dump()
```

**7. Customizing Serialization Fields:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class ProductSchema(ma.Schema):
    price = ma.Decimal(as_string=True)

product_schema = ProductSchema()
product_dict = product_schema.dump(product)
```

**8. Serializing to Different Formats:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()

user_schema = UserSchema()
user_json = user_schema.dump(user, output_format='json')
user_xml = user_schema.dump(user, output_format='xml')
```

**9. Validating Input:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(required=True)
    email = ma.String(required=True)

user_schema = UserSchema()
errors = user_schema.validate(user_data)
```

**10. Loading and Deserializing Input:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    email = ma.String()

user_schema = UserSchema()
user = user_schema.load(user_data)
```

**11. Overriding Default Serialization Behavior:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    email = ma.String()

    def get_name(self, obj):
        return obj.name.upper()

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**12. Using Custom Serializers:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class CustomSerializer(ma.Serializer):
    def serialize(self, value):
        return value.upper()

user_schema = ma.Schema(serializer=CustomSerializer)
user_dict = user_schema.dump(user)
```

**13. Filtering by Boolean Values:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    is_active = ma.Boolean()

user_schema = UserSchema()
filtered_user_dict = user_schema.dump(user, only=('name',))
```

**14. Validating Nested Objects:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(required=True)
    orders = ma.Nested(OrderSchema, validate=True, many=True)

order_schema = ma.Schema()
errors = user_schema.validate(user_data)
```

**15. Conditional Serialization:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    email = ma.String()

    def should_show_email(self, obj):
        return obj.is_admin

    class Meta:
        exclude = ('email',)
        conditionals = {
            'email': should_show_email
        }

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**16. Recursive Serialization:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    children = ma.Nested(lambda: UserSchema, many=True)

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**17. Specifying Field Path in Errors:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(required=True)
    orders = ma.Nested(OrderSchema, required=True, many=True)

order_schema = ma.Schema()
errors = user_schema.validate(user_data)
```

**18. Dynamic Schema Generation:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

def generate_user_schema(fields):
    return ma.Schema(fields=fields)

user_schema = generate_user_schema(('name', 'email'))
user_dict = user_schema.dump(user)
```

**19. Handling Multiple Level Nested Objects:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class OrderSchema(ma.Schema):
    items = ma.Nested(ItemSchema, many=True)

class UserSchema(ma.Schema):
    orders = ma.Nested(OrderSchema, many=True)

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**20. Advanced Conditional Serialization:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    email = ma.String()

    def should_show_email(self, obj):
        return obj.is_admin or obj.is_staff

    class Meta:
        exclude = ('email',)
        conditionals = {
            'email': should_show_email
        }

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**21. Serializing and Deserializing Relationships:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    orders = ma.Relationship(OrderSchema, many=True, backref='user')

order_schema = ma.Schema()
user_dict = user_schema.dump(user)
```

**22. Custom Error Handling:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(required=True)
    email = ma.String()

    class Meta:
        error_messages = {
            'required': 'This field is required.'
        }

user_schema = UserSchema()
errors = user_schema.validate(user_data)
```

**23. Using JSONAPI Serialization:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.ModelSchema):
    class Meta:
        include_fk = True

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**24. Controlling Field Serialization Order:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    email = ma.String()

    class Meta:
        ordered = True

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**25. Customizing Swagger/OpenAPI Documentation:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    email = ma.String()

    class Meta:
        swagger = {
            'description': 'User model'
        }

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**26. Menggunakan Skemata Terikat:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class User(ma.Model):
    name = ma.String()
    email = ma.String()

user_schema = ma.Schema.from_dict(User.query.first().to_dict())
user_dict = user_schema.dump(user)
```

**27. Mengatur Perilaku Deserialisasi:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    email = ma.String()

    class Meta:
        partial = True

user_schema = UserSchema()
updated_user = user_schema.load(updated_user_data, partial=True)
```

**28. Menggunakan Pengurai Dasar:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.RawSchema):
    name = ma.String()
    email = ma.String()

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**29. Menangani Serialisasi Tertunda:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(load_from='full_name')
    email = ma.String()

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**30. Menggunakan Serializer Kustom:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSerializer(ma.Serializer):
    def serialize(self, value):
        return value.upper()

user_schema = ma.Schema(serializer=UserSerializer)
user_dict = user_schema.dump(user)
```

**31. Menggunakan Filter dan Sort:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(filterable=True, sortable=True)
    email = ma.String(filterable=True)

user_schema = UserSchema()
filtered_sorted_users = user_schema.dump(User.query.filter(User.name=='John').order_by(User.name))
```

**32. Memvalidasi Input dengan Skemata:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String(required=True)
    email = ma.Email(required=True)

user_schema = UserSchema()
errors = user_schema.validate(user_data)
```

**33. Menggunakan Skemata Hierarkis:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class AddressSchema(ma.Schema):
    street = ma.String()
    city = ma.String()

class UserSchema(ma.Schema):
    name = ma.String()
    address = ma.Nested(AddressSchema)

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**34. Menangani Siklus Objek:**

```python
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    friends = ma.Nested(lambda: UserSchema, many=True)

user_schema = UserSchema()
user_dict = user_schema.dump(user)
```

**35. Menggunakan Skemata untuk Pengontrol:**

```python
from flask import Flask, jsonify

app = Flask(__name__)
ma = Marshmallow()

class UserSchema(ma.Schema):
    name = ma.String()
    email = ma.String()

@app.route('/users')
def get_users():
    users = User.query.all()
    user_schema = UserSchema()
    users_dict = user_schema.dump(users, many=True)
    return jsonify(users_dict)
```

**36. Menggunakan Skemata untuk Formulir Web:**

```python
from flask_wtf import Form
from flask_marshmallow import Marshmallow

ma = Marshmallow()

class UserForm(Form):
    name = wtforms.StringField()
    email = wtforms.EmailField()

class UserSchema(ma.Schema):
    name = ma.String()
    email = ma.Email()

@app.route('/users', methods=['POST'])
def create_user():
    form = UserForm()
    if form.validate_on_submit():
        data = form.data
        user_schema = UserSchema()
        user = user_schema.load(data)
        db.session.add(user)
        db.session.commit()
        return jsonify(user_schema.dump(user))
    return jsonify(errors=form.errors)
```