marshmallow-jsonschema translates marshmallow schemas into JSON Schema Draft v4 compliant jsonschema. See http://json-schema.org/
What are the use cases for this? Let's say you have a marshmallow schema in python, but you want to render your schema as a form in another system (for example: a web browser or mobile device).
pip install marshmallow-jsonschema
- https://github.com/brutusin/json-forms
- https://github.com/mozilla-services/react-jsonschema-form
- https://github.com/jdorn/json-editor
- https://github.com/ulion/jsonform
from marshmallow import Schema, fields
from marshmallow_jsonschema import JSONSchema
class UserSchema(Schema):
username = fields.String()
age = fields.Integer()
birthday = fields.Date()
user_schema = UserSchema()
json_schema = JSONSchema()
json_schema.dump(user_schema).dataYields:
{'properties': {'age': {'format': 'integer',
'title': 'age',
'type': 'number'},
'birthday': {'format': 'date',
'title': 'birthday',
'type': 'string'},
'username': {'title': 'username', 'type': 'string'}},
'required': [],
'type': 'object'}from marshmallow import Schema, fields
from marshmallow_jsonschema import JSONSchema
from tests import UserSchema
class Athlete(object):
user_schema = UserSchema()
def __init__(self):
self.name = 'sam'
class AthleteSchema(Schema):
user_schema = fields.Nested(JSONSchema)
name = fields.String()
athlete = Athlete()
athlete_schema = AthleteSchema()
athlete_schema.dump(athlete).data![Screenshot] (http://i.imgur.com/jJv1wFk.png)
This example renders a form not dissimilar to how wtforms might render a form.
However rather than rendering the form in python, the JSON Schema is rendered using the javascript library brutusin/json-forms.
from flask import Flask, jsonify
from marshmallow import Schema, fields
from marshmallow_jsonschema import JSONSchema
app = Flask(__name__)
class UserSchema(Schema):
name = fields.String()
address = fields.String()
@app.route('/schema')
def schema():
schema = UserSchema()
return jsonify(JSONSchema().dump(schema).data)
@app.route('/')
def home():
return '''<!DOCTYPE html>
<head>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/brutusin.json-forms/1.3.0/css/brutusin-json-forms.css"><Paste>
<script src="https://code.jquery.com/jquery-1.12.1.min.js" integrity="sha256-I1nTg78tSrZev3kjvfdM5A5Ak/blglGzlaZANLPDl3I=" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.string/3.3.4/underscore.string.min.js"></script>
<script src="https://cdn.jsdelivr.net/brutusin.json-forms/1.3.0/js/brutusin-json-forms.min.js"></script>
<script>
$(document).ready(function() {
$.ajax({
url: '/schema'
, success: function(data) {
var container = document.getElementById('myform');
var BrutusinForms = brutusin["json-forms"];
var bf = BrutusinForms.create(data);
bf.render(container);
}
});
});
</script>
</head>
<body>
<div id="myform"></div>
</body>
</html>
'''
if __name__ == '__main__':
app.run(host='0.0.0.0', debug=True)Simply add a _jsonschema_type_mapping method to your field
so we know how it ought to get serialized to JSON Schema.
A common use case for this is creating a dropdown menu using enum (see Gender below).
class Colour(fields.Field):
def _jsonschema_type_mapping(self):
return {
'type': 'string',
}
def _serialize(self, value, attr, obj):
r, g, b = value
r = hex(r)[2:]
g = hex(g)[2:]
b = hex(b)[2:]
return '#' + r + g + b
class Gender(fields.String):
def _jsonschema_type_mapping(self):
return {
'type': 'string',
'enum': ['Male', 'Female']
}
class UserSchema(Schema):
name = fields.String(required=True)
favourite_colour = Colour()
gender = Gender()
schema = UserSchema()
json_schema = JSONSchema()
json_schema.dump(schema).data