jsonschema validation on flask

jsonschema をつかってpostされてきたjsonのバリデーションを行い、エラーのあるフィールドがあったら処理を中断してどこにエラーがあったのかをステータスコード400のjsonでレスポンスする

app.py

from flask import Flask
app = Flask(__name__)

import json_schema
import json


schema = {
  "name": {
    "type": "string",
    "required": True
  },
  "age": {
    "type": "number",
    "required": True
    "maximum": 120,
    "minimum": 0
  }
}

@app.route("/")
@json_schema.validate("POST", schema)
def index():
    if request.is_post:
        data = json.loads(request.data)
        print data["name"]
        print data["age"]
        return "Hi! "+data["name"]
    else:
        return "Hi!"

if __name__ == "__main__":
    app.run()

---

json_schema.py

import json
from jsonschema import ValidationError, exceptions
from jsonschema.validators import Draft3Validator
 
from functools import wraps
 
from flask import _request_ctx_stack, request, jsonify
 
def _validate(schema, data):
    reqv = Draft3Validator(schema)
    errors = []
    for e in reqv.iter_errors(data):
        errors.append(dict(name=e.path[0], reason=e.validator))
    return errors
 
def validate(method, schema):
    def decorator(f):
        @wraps(f)
        def decorated_func(*args, **kws):
            ctype = request.headers.get("Content-Type")
            method_ = request.headers.get("X-HTTP-Method-Override", request.method)
            if method_.lower() == method.lower() and "json" in ctype:
                data = json.loads(request.data)
                errors = _validate(schema, data)
                if len(errors) > 0:
                    resp = jsonify(result="failure", reason="invalid json", errors=errors)
                    resp.status_code = 400
                    return resp
            return f(*args, **kws)
        return decorated_func
    return decorator