I'm just trying to set up a blog with Rails using MongoDB for my persistence layer. As part of that I'd like to embed comments in my posts but every time I do, it fails calling ActiveModel::ForbiddenAttributesError, which I know has to do with the strong_parameters gem in Rails. this is what my controller looks like
class CommentsController < ApplicationController
def create
#post = Post.find(params[:post_id])
#comment = #post.comments.create!(params[:comment])
redirect_to #post
end
private
def comment_params
params.require(:comment).permit(:by, :published_on, :body)
end
end
Can anyone see where I'm going wrong?
You can't just pass the params hash like you do. You must use the return value of the permit method instead. Like this:
#comment = #post.comments.create!(comment_params)
Related
I'm exporting data from a legacy Django application and have written a script that imports the old models.py, which are something like this:
class GeneralType(models.Model):
...
publications = models.ManyToManyField(Publication, blank=True)
class Publication(models.Model):
...
authors = models.TextField()
url = models.URLField(blank=True)
class Record(GeneralType):
...
name = models.CharField(max_length=128)
So, this should work:
for r in Record.objects.all():
for p in r.publications.all(): # Exception thrown here
print(p.url)
But instead it gives:
django.core.exceptions.FieldError: Cannot resolve keyword 'generaltype' into field. Choices are: authors, url
So, there's some issue with calling GeneralType methods on a Record instance, presumably related to having abstracted this out to a script, as everything is fine if similar code is run in the Django app.
There's probably something obvious I've missed here - would happen to know what it is?
I am using Django Rest Framework for a project and I have a nested serializer like this:
class TopSerializer(serializers.ModelSerializer):
contact = (something goes here)
email = (something goes here)
For POST, PATCH, PUT, DELETE I want to specify these values with a slug. Suppose each class (Contact, Email) has a member called resource_id and that is my slug. For these methods I could use:
class TopSerializer(serializers.ModelSerializer):
contact = serializers.SlugRelatedField(read_only=False, slug_field='resource_id')
email = serializers.SlugRelatedField(read_only=False, slug_field='resource_id')
However, for GET I want to return the embedded objects too, so I could use:
class TopSerializer(serializers.ModelSerializer):
contact = ContactSerializer(read_only=True)
email = EmailSerializers(read_only=True)
So how do I specify in my serializer that contact can be either a slug or a serialized object? Is there a way to do this with just one serializer or must I have two different serializers and use the request.method in the view to select which serializer I use?
Or, should I use something like this:
class TopSerializer(serializers.ModelSerializer):
contact = ContactSerializer(read_only=True)
email = EmailSerializers(read_only=True)
contact_rid = serializers.SlugRelatedField(read_only=False,slug_field=resource_id,queryset=models.Contact.objects.all())
email_rid = serializers.SlugRelatedField(read_only=False,slug_field=resource_id,queryset=models.Email.objects.all())
This way I can use contact_rid and email_rid for POST/PATCH/PUT/DELETE and get contact and email fields back in GET.
Am I on the right track? Other suggestions?
Check out custom fields https://www.django-rest-framework.org/api-guide/fields/#custom-fields
You could define a custom serializer fields that overrides serializers.Field and overrride to_representation to return the fully serialized object and to_internal_value to mimic the behavior of a slugRelatedField.
You are on the right track!
Use one related field for write and another to read the full object is a good approach if you need more details for related objects.
You can also add to the slug field the flag write_only=True if you want the field is used only for write. However, checking this option will not hint selected objects when you are under an update route in Browseable API
Check this anwser
Context
I have the following data structure:
class Birthday(ndb.Model):
day = ndb.IntegerProperty()
month = ndb.IntegerProperty()
year = ndb.IntegerProperty()
class User(ndb.Model):
name = ndb.StringProperty()
birthday = ndb.StructuredProperty(Birthday)
# ... other properties
Problem
When I try to use the populate() method on an instance of User, it gives an error: expecting a Birthday instance instead of a dictionary of params.
If I remove the birthday property, everything works fine: the User instance is populated with the dictionary of params.
Shouldn't the populate() method recognize structured properties and automatically populate them as well?
Any clues?
Thanks
PS: The populate method could also use a forgiving mode on which it ignores unknown properties for which there are references on the params dictionary.
>>Added comments
I'm using a generic REST Handler which is extended for accessing and changing several data types. The extension has to define a method getModel() that returns the model class to access/manipulate. The model class has to implement a few methods, namely create(cls, params).
The POST handler parses params (sent by AngularJS using $resouce -- link below) the following way:
# inside the generic REST Handler
params = json.loads(self.request.body, object_hook=self.datetime_decoder) # parse json params
...
self.getModel().create(params) # invokes the create method of the
The model class implements the create method the following way:
#classmethod
def create(cls, params = None):
obj = cls()
if params:
obj.update(**params)
obj.put()
return True, obj
return False, None
The contents of the JSON dict are:
{"name":"Ana Matos","email":"ana.matos#nvd.com","phone":"+35196983465671","birthday":{"day":1,"month":0,"year":1980},"gender":"FEMALE","groups":["2012/2013"],"serviceProviderId":206133}
JSON contens -- firefox screenshot
AngularJS $resource
Are you reporting a bug or requesting a feature? The populate() method requires its parameter types to match the declared type of the property, which in this case is a Birthday instance.
It would help if you showed the contents of the JSON dict that you are passing to populate() (and exactly how you are passing it).
Possibly the solution is as simple as getting the 'birthday' value from the JSON dict and using it to create a Birthday instance. But I would have to see your code to know for sure.
I have a requirement to design a RESTful Service using RESTEasy. Clients can call this common service with any number of Query Parameters they would want to. My REST code should be able to read these Query Params in some way. For example if I have a book search service, clients can make the following calls.
http://domain.com/context/rest/books/searchBook?bookName=someBookName
http://domain.com/context/rest/books/searchBook?authorName=someAuthor& pubName=somePublisher
http://domain.com/context/rest/books/searchBook?isbn=213243
http://domain.com/context/rest/books/searchBook?authorName=someAuthor
I have to write a service class like below to handle this.
#Path("/books")
public class BookRestService{
// this is what I currently have, I want to change this method to in-take all the
// dynamic parameters that can come
#GET
#Path("/searchBook")
public Response searchBook(#QueryParam("bookName") String bookName,#QueryParam("isbn") String isbn) {
// fetch all such params
// create a search array and pass to backend
}
#POST
#Path("/addBook")
public Response addBook(......) {
//....
}
}
Sorry for the bad format (I couldn't get how code formatting works in this editor!). As you can see, I need to change the method searchBook() so that it will take any number of query parameters.
I saw a similar post here, but couldn't find the right solution.
How to design a RESTful URL for search with optional parameters?
Could any one throw some light on this please?
The best thing to do in this case would be using a DTO containing all the fields of your search criteria. For example, you mentioned 4 distinct parameters.
Book Name (bookName)
Author Name (authorName)
Publisher Name (pubName)
ISBN (isbn)
Create a DTO containing the fields having the following annotations for every property you want to map the parameters to:
public class CriteriaDTO{
#QueryParam("isbn")
private String isbn;
.
.
Other getter and setters of other properties
}
Here is a method doing that for your reference:
#GET
#Produces("application/json")
#Path("/searchBooks")
public ResultDTO search(#Form CriteriaDTO dto){
}
using following URL will populate the CriteriaDTO's property isbn automatically:
your.server.ip:port/URL/Mapping/searchBooks?isbn=123456789&pubName=testing
A similar question was asked here: How do you map multiple query parameters to the fields of a bean on Jersey GET request?
I went with kensen john's answer (UriInfo) instead. It allowed to just iterate through a set to check which parameters were passed.
Recently there's been some data structure changes in our app, and we decided to use namespaces to separate different versions of of the data, and a mapreduce task that converts old entities to the new format.
Now that's all fine, but we don't want to always isolate the entire data set we have. The biggest part of our data is stored in a kind that's pretty simple and doesn't need to change often. So we decided to use per-kind namespaces.
Something like:
class Author(ndb.model.Model):
ns = '2'
class Book(ndb.model.Model):
ns = '1'
So, when migrating to version 2, we don't need to convert all our data (and copy all 'Book' kinds to the other namespace), only entities of the 'Author' kind. Then, instead of defining the appengine_config.namespace_manager_default_namespace_for_request, we just the 'namespace' keyword arguments to our queries:
Author.query(namespace=Author.ns).get()
Question: how to store (i.e. put()) the different kinds using these different namespaces? Something like:
# Not an API
Author().put(namespace=Author.ns)
Of course, the above doesn't work. (Yes, I could ask the datastore for an avaliable key in that namespace, and then use that key to store the instance with, but it's an extra API call that I'd like to avoid.)
To solve a problem like this I wrote a decorator as follows:
MY_NS = 'abc'
def in_my_namespace(fn):
"""Decorator: Run the given function in the MY_NS namespace"""
from google.appengine.api import namespace_manager
#functools.wraps(fn)
def wrapper(*args, **kwargs):
orig_ns = namespace_manager.get_namespace()
namespace_manager.set_namespace(MY_NS)
try:
res = fn(*args, **kwargs)
finally: # always drop out of the NS on the way up.
namespace_manager.set_namespace(orig_ns)
return res
return wrapper
So I can simply write, for functions that ought to occur in a separate namespace:
#in_my_namespace
def foo():
Author().put() # put into `my` namespace
Of course, applying this to a system to get the results you desire is a bit beyond the scope of this, but I thought it might be helpful.
EDIT: Using a with context
Here's how to accomplish the above using a with context:
class namespace_of(object):
def __init__(self, namespace):
self.ns = namespace
def __enter__(self):
self.orig_ns = namespace_manager.get_namespace()
namespace_manager.set_namespace(self.ns)
def __exit__(self, type, value, traceback):
namespace_manager.set_namespace(self.orig_ns)
Then elsewhere:
with namespace_of("Hello World"):
Author().put() # put into the `Hello World` namespace
A Model instance will use the namespace you set with the namespace_manager[1] as you can see here: python/google/appengine/ext/db/init.py
What you could do is create a child class of Model which expects a class-level 'ns' attribute to be defined. This sub class then overrides put() and sets the namespace before calling original put and resets the namespace afterwards. Something like this:
'''
class MyModel(db.Model):
ns = None
def put(*args, **kwargs):
if self.ns == None:
raise ValueError('"ns" is not defined for this class.')
original_namespace = namespace_manager.get_namespace()
try:
super(MyModelClass, self).put(*args, **kwargs)
finally:
namespace_manager.set_namespace(original_namespace)
'''
[1] http://code.google.com/appengine/docs/python/multitenancy/multitenancy.html
I don't think that it is possible to avoid the extra API call. Namespaces are encoded into the entity's Key, so in order to change the namespace within which a entity is stored, you need to create a new entity (that has a Key with the new namespace) and copy the old entity's data into it.