Tools to play with json-schemas defined APIs.
These tools are based on json-schema draft 3 from http://tools.ietf.org/html/draft-zyp-json-schema-03
Not all features of the schema are supported and probably won't be.
Handling of not supported feature varies between the different tools.
All these tools are proofs of concept and work in progress, they need more extensive testing and documentation.
datagenerator
Class to generate random values given a json-schema.
Doesn't support all json-schema monstruousities, only a subset I find useful.
See TODO.md for what is likely to be implemented next.
Examples
from datagenerator import DataGenerator
generator = DataGenerator()
Basic
Generate random values of each basic type using
>>> generator.random_value("string")
'Olzq3LV'
>>> generator.random_value("number")
-6.675904074356879
>>> generator.random_value("integer")
30
>>> generator.random_value("boolean")
True
Basic with constraints
number
>>> generator.random_value({"type":"number", "minimum":30})
32.34295327292445
>>> generator.random_value({"type":"number", "maximum":30})
-35.80704939879546
>>> generator.random_value({"type":"number", "maximum":30, "minimum":12})
16.45747265846327
integer
supports minimum
and maximum
like number
and more
>>> generator.random_value({"type":"integer", "maximum":30, "divisibleBy":4, "minimum":12})
24
>>> generator.random_value({"type":"integer", "maximum":30, "exclusiveMaximum":True, "minimum":28})
29
(same for exclusiveMinimum
)
string
supports minLength
, maxLength
, pattern
(ignores minLength
and maxLength
if pattern
is used)
>>> generator.random_value({"type":"string", "maxLength":20, "minLength":15})
'VytPCEdAImX11188HU'
>>> generator.random_value({"type":"string", "pattern":"[0-9]{3}[a-zA-Z]{2,5}"})
u'806FoNP'
boolean
doesn't have any constraints.
Arrays
Without constraints the array size will be picked the same way as a random integer
.
Each item in the array is generated using the default generator for the type given in items
.
>>> generator.random_value({"type":"array", "items": {"type":"string"}})
[
'39yxcpvS5tfPf6O',
'sNDk7SlGNQstxxx',
'nPcRSD9yIP7j ',
'PWP7KQfjc1',
'tt6F6Z2YEp'
]
minItems
, maxItems
and uniqueItems
are supported
The type of object in items
can be anything that the generator knows about, either one of the basic types
or a user defined one available from the generator's schemas store.
from schemasstore import SchemasStore
...
>>> from schemasstore import SchemasStore
>>> store = SchemasStore()
>>> generator.schemas_store = store
>>> store.add_schema({"type":"integer", "name":"small_integer", "minimum":0,"maximum":9})
True
>>> generator.random_value({"type":"array", "uniqueItems":True, "minItems":10, "items":{"type":"small_integer"}})
[0, 7, 2, 5, 3, 6, 1, 4, 8, 9]
See datagenerator for other examples.
Objects
Objects can be generated the same way as the other types.
Example generating search_result.json
>>> store.load_folder("data/schemas/")
>>> generator.random_value("search_result")
{u'price': 21.980325774975253, u'name': 'wdvfXYrrt', u'reference': 26}
Generating arrays of objects is fine as well
>>> generator.random_value({"type":"array", "maxItems":3, "minItems":2, "items":{"type":"search_result"}})
[
{u'price': 20.304440535786522, u'name': 'VUIgjaPbs', u'reference': 40},
{u'price': 28.45387747055259, u'name': 'JTycBU1V78X1S', u'reference': 27}
]
Or generating objects with arrays of other objects in them, see
search_resuts
with an array of search_result
>>> generator.random_value("search_results")
{
u'total_results': 41,
u'total_pages': 26,
u'current_page': 33,
u'items_per_page': 27,
u'results': [
{u'price': 26.218704680177446, u'name': 'B4p1Z1pOFQO', u'reference': 38},
{u'price': 21.205089550441276, u'name': 'FQPHdLds', u'reference': 7},
{u'price': 20.610536930894398, u'name': '8D862p1XVupP', u'reference': 38},
{u'price': 9.543934434058526, u'name': 'PmqBA0e DIWisf', u'reference': 32}
]
}
Schemas
Why not generate random schemas?
>>> r_schema = generator.random_schema()
>>> r_schema
{
'type': 'object',
'properties': {
u'viYXjhu': {'required': False, 'type': 'boolean'},
u'TO': {'required': False, 'type': 'string'},
u'NTSd': {'required': False, 'type': 'string'},
u'WjaL': {'required': False, 'type': 'string'},
u'PtvhZ': {'required': False, 'type': 'boolean'}
},
'name': u'zJllGkKosmocOVO'
}
And then generate an array of random values of it
>>> store.add_schema(r_schema)
True
>>> generator.random_value({"type":"array", "minItems":1, "maxItems":3, "items":{"type":"zJllGkKosmocOVO"}})
[
{u'TO': 'jamKFpdwY'},
{u'WjaL': '8LnibWUdsSI', u'PtvhZ': True},
{}
]
Notes on the generation
All the values are generated using the random
module, so please don't use the generate values for anything
requiring reliable randomness == don't use it to generate passwords.
To generate the data, the generator has to limit the range of possible values, so the values generated don't
vary too wildly. The ranges are controlled by variables in DataGenerator
. Feel free to tweak them, especially
if you need values that don't fall into those ranges without having to set both minimum and maximum on your
properties.
urlsgenerator
Class to generate links defined in the links section of a json-schema.
Example
Generate links from book.json
Input
...
"isbn" : {
"type":"string",
"required":true,
"pattern":"^\\d{12}(\\d|X)$"
}
},
"links" : [
{
"rel":"self",
"href":"books/{isbn}"
},
{
"rel":"instances",
"href": "books"
}
]
...
Output
{
u'instances': [u'books'],
u'self' : [u'books/525259838909X']
}
{isbn}
got replaced by a random value 525259838909X
satisfying the constraints on isbn
(matches the regex).
invaliddatagenerator
Class to generate invalid data for a given schema
Basically does the opposite of datagenerator. WIP, needs documentation and examples.
modelgenerator
Base class to generate models from a schema, nothing too visible on its own, check resourceserver
.
flasksqlalchemymodelgenerator
Generate SQLAlchemy models to be used with flask-sqlalchemy from a schema. Uses modelgenerator
.
Used in resourceserver
to store and query items.
backbonemodelgenerator
Generate models and collections for Backbone.js from a schema.
The models generated use the primary key defined in the rel=self
link or id
by default.
To be able to use collections, make sure your schema has a rel=instances
link or fetch
won't work.
Usage
$ python backbonemodelgenerator.py -h
Usage: backbonemodelgenerator.py jsonfile1 [jsonfile2]...
Options:
-h, --help show this help message and exit
-t OUTPUT_TYPE, --type=OUTPUT_TYPE
Output type (js|wrapped|html)
Output types
js
Outputs only the js code for the models/collections
$ python backbonemodelgenerator.py -t js data/schemas/message.json
App.Models.Message = Backbone.Model.extend({
urlRoot: '/messages',
idAttribute: 'id'
});
App.Collections.Messages = Backbone.Collection.extend({
model : App.Models.Message,
url : "/messages"
});
wrapped
Wraps the js code into $(document).ready()
$ python backbonemodelgenerator.py -t wrapped data/schemas/message.json
$(document).ready(function() {
window.App = { Models : {}, Collections : {} };
App.Models.Message = Backbone.Model.extend({
urlRoot: '/messages',
idAttribute: 'id'
});
App.Collections.Messages = Backbone.Collection.extend({
model : App.Models.Message,
url : "/messages"
});
});
html
Same as wrapped but generate a whole html page including jQuery, Backbone and Underscore to easily test.
Example usage
Setup
You can use it with resource server for example
$ mkdir static
$ python backbonemodelgenerator.py -t html data/schemas/message.json > static/index.html
$ python resourceserver.py data/schemas/message.json
Added message
* Running on http://0.0.0.0:5000/
Now open your browser at http://0.0.0.0:5000/static/index.html
Open your js console to start playing
Create a collection and fetch them
var col = new App.Collections.Messages()
col.fetch()
You should see backbone talking to the resource server in the server shell
127.0.0.1 - - [20/Nov/2012 01:17:15] "GET /messages HTTP/1.1" 200 -
You can inspect the results using
col.models
Using fetch() only works if your schema includes a link with rel=instances
Create a new message
var msg = new App.Models.Message({recipient:"01234567890", text:"test message"})
msg.attributes
At that point the message is not saved yet, you can verify by using
msg.isNew()
You can save it on the server using
msg.save()
You can verify that the message was sent to the server in the server shell
127.0.0.1 - - [20/Nov/2012 01:23:24] "POST /messages HTTP/1.1" 201 -
Now you should have an id for the message and it shouldn't be marked as new anymore.
msg.id
msg.isNew()
Fetch an existing message
Create a message with the id
of the message to fetch
var msg = new App.Models.Message({id: 3})
The message is not marked as new as it has an id.
We can then fetch the actual message from the server using
msg.fetch()
msg.attributes()
You can see the query in the server shell again
127.0.0.1 - - [20/Nov/2012 01:25:41] "PUT /messages/3 HTTP/1.1" 200 -
Update a message
Once you have a message object, you can update it using save
.
> msg.attributes.recipient
"01234567890"
> msg.save({recipient:"00123456789"})
> msg.attributes.recipient
"00123456789"
This is done by doing a PUT
on the server
127.0.0.1 - - [20/Nov/2012 01:33:35] "PUT /messages/3 HTTP/1.1" 200 -
Delete a message
Simply use destroy
on the object
msg.destroy()
And see the DELETE
happening on the server
127.0.0.1 - - [20/Nov/2012 01:34:48] "DELETE /messages/3 HTTP/1.1" 204 -
resourceserver
Class to implement the REST api of resources defined in a schema.
Supports creation, update, retrieval, deletion, listing of instances and schema.
Usage
Run the server using
$ python resourceserver.py [jsonfile1, jsonfile2, ...]
Example using data/schemas/message.json
$ python resourceserver.py data/schemas/message.json
Added message
* Running on http://0.0.0.0:5000/
Create a new message
$ curl -i -X POST http://0.0.0.0:5000/messages -d "recipient=07771818335&text=nice message"
$ curl -i -X POST http://0.0.0.0:5000/messages -d '{"recipient":"01234567890", "text":"test"}' \
-H "Content-Type: application/json"
HTTP/1.0 201 CREATED
Content-Type: application/json
Content-Length: 13
Location: http://0.0.0.0:5000/messages/2
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 19:28:56 GMT
{
"id": 2
}
List messages
$ curl -i -X GET http://0.0.0.0:5000/messages
HTTP/1.0 200 OK
Content-Type: application/json
Content-Length: 126
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 19:32:09 GMT
[
{"text": "I </3 ninjas", "recipient": "07771818337", "id": 1},
{"text": "nice message", "recipient": "07771818335", "id": 2}
]
Retrieve a message
$ curl -i -X GET http://0.0.0.0:5000/messages/2
HTTP/1.0 200 OK
Content-Type: application/json
Content-Length: 71
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 19:35:42 GMT
{
"text": "nice message",
"recipient": "07771818335",
"id": 2
}
Get the json-schema of a message
$ curl -i -X OPTIONS http://0.0.0.0:5000/messages/2
HTTP/1.0 200 OK
Content-Type: application/json
Content-Length: 590
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 19:37:06 GMT
{
"description": "Simple message structure",
"type": "object",
"properties": {
"text": {
"required": true,
"type": "string",
"maxLength": 140
},
"recipient": {
"pattern": "0[0-9]{10}",
"required": true,
"type": "string"
},
"id": {
"minimum": 0,
"type": "integer"
}
},
"links": [
{
"href": "/messages",
"rel": "root"
},
{
"href": "{id}",
"rel": "self"
},
{
"rel": "instances"
},
{
"rel": "create"
}
],
"name": "message"
}
Update a message
Supports partial updates
$ curl -i -X PUT http://0.0.0.0:5000/messages/2 -d 'recipient=07771818336'
$ curl -i -X PUT http://0.0.0.0:5000/messages/1 -d '{"text":"foo"}' \
-H "Content-Type: application/json"
HTTP/1.0 200 OK
Content-Type: text/html; charset=utf-8
Content-Length: 0
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 19:38:02 GMT
Delete a message
$ curl -i -X DELETE http://0.0.0.0:5000/messages/2
HTTP/1.0 204 NO CONTENT
Content-Type: text/html; charset=utf-8
Content-Length: 0
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 19:38:38 GMT
Errors examples
Trying to set an implicit key
The message.json doesn't define an explicit primary key, but defines id
as the key in the rel=self
link.
Each message then gets an additional id
key managed by the server.
Trying to set or update the id
results in errors
$ curl -i -X POST http://0.0.0.0:5000/messages -d "recipient=07771818335&text=nice message&id=7"
$ curl -i -X PUT http://0.0.0.0:5000/messages/1 -d "recipient=07771818335&text=nice message&id=3"
HTTP/1.0 400 BAD REQUEST
Content-Type: application/json
Content-Length: 43
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 19:43:48 GMT
{
"error": "id is read only in message"
}
Trying to create or update unknown properties
$ curl -i -X POST http://0.0.0.0:5000/messages -d "recipient=07771818335&tet=test&haxxy=foo"
$ curl -i -X PUT http://0.0.0.0:5000/messages/1 -d "haxxy=foo"
HTTP/1.0 400 BAD REQUEST
Content-Type: application/json
Content-Length: 57
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 19:56:19 GMT
{
"error": "message does not have a 'haxxy' property"
}
Trying to create or update properties with values not respecting constraints
$ curl -i -X PUT http://0.0.0.0:5000/messages/1 -d "recipient=0notanumber&text=nice message"
$ curl -i -X POST http://0.0.0.0:5000/messages -d "recipient=0notanumber"
HTTP/1.0 400 BAD REQUEST
Content-Type: application/json
Content-Length: 86
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 20:03:34 GMT
{
"error": "'0notanumber' is an invalid recipient value: must match u'0[0-9]{10}'"
}
Trying to create a message without all the required properties
$ curl -i -X POST http://0.0.0.0:5000/messages -d "recipient=012345678901"HTTP/1.0 400 BAD REQUEST
Content-Type: application/json
Content-Length: 44
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Sun, 18 Nov 2012 20:06:00 GMT
{
"error": "text is required in message"
}
Trying to create a message in json with invalid data
$ curl -i -X POST http://0.0.0.0:5000/messages -d '{"recipient":"01234567890", "text":"test}' -H "Content-Type: application/json"
HTTP/1.0 400 BAD REQUEST
Content-Type: application/json
Content-Length: 90
Server: Werkzeug/0.8.3 Python/2.7.3
Date: Tue, 20 Nov 2012 00:23:05 GMT
{
"error": "Invalid data: Unterminated string starting at: line 1 column 35 (char 35)"
}
Primary keys
Each model needs a primary key.
There are 3 ways to define the primary key of the model:
If there is no rel=self
link, an additional id
(or appended with as many _
as
necessary to make the name unique) attribute is created. This type of key is called implicit and can
only be set by the server (read only).
If there is a rel=self
link and it contains a {variable}
part, the variable name is used as the primary key.
- If
variable
is the name of an existing property, this property is used as the primary key, and can be updated
( explicit key ) - Otherwise an implicit key is created using the
variable
name (stil read-only).
Example of an explicit key
This schema uses isbn
as the explicit key. Instances can be created using a specific isbn
, and its value
can be updated.
...
"isbn" : {
"type":"string",
"required":true,
"pattern":"^\\d{12}[\\d|X]$"
}
},
"links" : [
{
"rel":"self",
"href":"books/{isbn}"
},
...
Example of implicit key
This schema defines an implicit key order_id
(assuming no property is called order_id
).
...
"links" : [
{
"rel":"self",
"href":"{order_id}"
},
...
Dependencies
Optional
datagenerator, invaliddatagenerator and urlgenerator
Use rstr
hosted in a mercurial repo on bitbucket. Run init.sh
in dependencies to fetch it.
If you don't have mercurial, apt-get install mercurial
should help.
flasksqlalchemymodelgenerator and resourceserver
flask-sqlalchemy is required, use flasksqlalchemy-requirements.txt with virtualenv
backbonemodelgenerator
jinja2 is required, comes with flask if you use the flasksqlalchemy-requirements.txt