Base Request Handler

Specific abilities

  • self.rate_limiters

    • Array of q2_sdk.core.RateLimiter instances. Allows for limiting traffic to the extension either by ip (segment_by_ip=True) or globally (segment_by_ip=False)

    • Useful for mitigating Distributed Denial of Service (DDoS) attacks

class q2_sdk.core.http_handlers.base_handler.Q2BaseRequestHandler(application, request, **kwargs)[source]

Bases: RequestHandler

Inherits from Tornado’s RequestHandler, but adds a few Q2 specific niceties.

  • Handles both gets and posts

  • If REQUIRED_CONFIGURATIONS is set, ensures the entries are set in the extension’s settings file or the webserver will not start.

    REQUIRED_CONFIGURATIONS is a dictionary of key value pairs where the key is the required name and the value is the default value when q2 generate_config is called

  • If DYNAMIC_CORE_SELECTION is set to True, will prompt for a Core name on installation

  • OPTIONAL_CONFIGURATIONS work the same was as REQUIRED_CONFIGURATIONS, but will not stop the server from running if omitted

  • FRONTEND_OVERRIDE_EXTENSION allows using another extension as the frontend for this one

data_received(_)[source]

Implement this method to handle streamed request data.

Requires the stream_request_body decorator.

May be a coroutine for flow control.

async run_async(funcname, *args, **kwargs)[source]

Easy way to run a non_async function in a background thread

Usage:

def non_async_func(foo, spam=”eggs”):

time_consuming_thing()

await self.run_async(non_async_func, 1, spam=”eggs”)

Parameters:

  • funcname (Callable) – Function reference (do not instantiate)

  • args – Positional parameters

  • kwargs – Keyword parameters

property core: BaseCore

Instantiates a communication object between this extension and the core listed in configuration.settings.CORE Must pip install q2_cores or populate settings.CUSTOM_CORES for this to be accessible

Returns:

Subclass of q2_sdk.models.cores.BaseCore

property cache: Q2CacheClient

Instantiates a communication object between this extension and the pymemcache library. Cache can be configured via configuration.settings.CACHE.

This is a factory that instantiates the cache in self.default_cache_level. There is also self.stack_cache, self.service_cache, or self.session_cache for direct access based on your context.

property service_cache: Q2CacheClient[source]

Q2CacheClient scoped to the loadbalanced running service.

property stack_cache: Q2CacheClient[source]

Q2CacheClient scoped to the current financial institution stack.

property session_cache: Q2CacheClient[source]

Same as self.cache but limited to online user session

get_cache(prefix=None, **kwargs)[source]
Parameters:

prefix – If defined will be prepended to all keys

Return type:

Q2CacheClient

property base_assets_url

Url to use for creating a fully qualified URL to your extension assets

async get_ui_text(language=None, ui_selection=None, cache_time=60)[source]

Returns any UI Text elements from the database that were inserted as part of self.DB_PLAN

Return type:

dict

async prepare()[source]

Fires before any request handling code

By default, will check any Rate Limiter instances in self.rate_limiters and disallow further processing if any are over their specified limit

on_finish()[source]

Fires as the request is ending

log_exception(typ, value, tb)[source]

Override to customize logging of uncaught exceptions.

By default logs instances of HTTPError as warnings without stack traces (on the tornado.general logger), and all other exceptions as errors with stack traces (on the tornado.application logger). :rtype: None

Added in version 3.1.

get_template(template_name, replacements_dict)[source]

Used for loading static blocks of text with substitutions. Great for storing large HTML blocks in separate files. Uses jinja behind the scenes (http://jinja.pocoo.org/)

Will search in all templates folders starting with the calling extension, then moving on to the parent class, and so on, preferring the lowest.

Parameters:

  • template_name (str) – file_name including suffix. ex. initial.html

  • replacements_dict (dict) – Key value pairs to replace within template_name

Return type:

str

Returns:

Body of template_name file replaced with values in replacements_dict