garnet

About

garnet is a ridiculously simple library created mainly for managing your stateful telegram bots written with Telethon.

How to install?

Although, garnet is garnet, it is named telegram-garnet on the PyPI, you'll have to tell that to pip.

pip install -U telegram-garnet

Let's dive in

# export BOT_TOKEN, APP_ID, APP_HASH, SESSION_DSN env vars.
from garnet import ctx
from garnet.events import Router
from garnet.filters import State, text, group
from garnet.storages import DictStorage

router = Router()
UserStates = group.Group.from_iter(["echo"])  # declare users states

# register handler for "/start" commands for users with none yet set state
@router.message(text.commands("start"), State.entry)
async def entrypoint(event):
    await event.reply("You entered echo zone!\n/cancel to exit")
    fsm = ctx.CageCtx.get()
    await fsm.set_state(UserStates.echo)

# register handler for "/cancel" commands for users that have entered any state
@router.message(text.commands("cancel"), State.any)
async def cancel(event):
    await event.reply("Cancelled :)\n/start to restart")
    await ctx.CageCtx.get().set_state(None)

# handle any message from users with state=UserState.echo
@router.message(State.exact(UserStates.echo))
async def echo(event):
    await event.reply(event.text)

if __name__ == "__main__":
    from garnet.runner import run, launch
    launch("my-first-garnet-app", run(router, DictStorage()))

Key features

Filters

Basically Filter is a "lazy" callable which holds an optional single-parameter function. Filters are event naive and event aware. Filters are mutable, they can migrate from event-naive to event-aware in garnet.

Public methods

• .is_event_naive -> bool
• .call(e: T, /) -> Awaitable[bool]

Initializer

Filter(function[, event_builder])

Value of the parameter function must be function that takes exactly one argument with type Optional[Some] and returns bool either True or False.

Possible operations on Filter instances

(those are, primarily logical operators)

Binary

• & is a logical AND for two filters
• | is a logical OR for two filters
• ^ is a logical XOR for two filters

Unary

• ~ is a logical NOT for a filter

Examples

from garnet import Filter, events

async def fun(_): ...

# example of event aware filter
Filter(fun, events.NewMessage)

# example of event-naive
Filter(fun)

By default Filter is event-naive, however when using with garnet::Router for handlers it may be changed.

Filters "from the box"

Text filters

Operations on Filter((e: Some) -> bool); Some.raw_text or Some.text

Import

from garnet.filters import text

Little journey

• text.Len is a special class for len(Some.raw_text ... "") operations. Supports logical comparison operations, such are ==, >, >=, <, <=
• text.startswith(prefix: str, /) will evaluates to Some.raw_text.startswith(prefix)
• text.commands(*cmds: str, prefixes="/", to_set=True) will evaluate to check if command is within cmd (ignores mentions, and works on Some.text)
• text.match(rexpr: str, flags=0, /) will evaluate to re.compile(rexpr, flags).match(Some.raw_text)
• text.between(*texts: str, to_set=True) will evaluate to Some.raw_text in texts
• text.can_be_int(base=10) will evaluate to try{int(Some.raw_text);return True;}except(ValueError){return False;}
• text.can_be_float() similarly to text.can_be_int but for floats.

State filters

Operations on users' states.

Import

from garnet.filters import State

Little journey

• State.any will evaluate to match any state but not None
• State.entry will evaluate to True if only current state is None
• State.exact(state: GroupT | M | "*") when "*" is passed will use State.any, when states group is passed will check if current state is any states from the group, when state group member (M) passed will check if current state is exactly this state
• State == {some} will call State.exact(state=some)

Note

State filter has effect on garnet.ctx.MCtx. And if you're not sure what are you doing try not to apply logical operators on State filters. Simply, don't do ~State.any or ~State.exact(...some...)

States declaration

Import

from garnet.filters import group

group.M (state group Member)

yes, "M" stands for member.

• .next return the next M in the group or raise group.NoNext exception
• .prev return the previous M in the group or raise group.NoPrev exception
• .top return the top (head) M in the group or raise group.NoTop exception

group.Group

Group of state members declared as a class (can be nested)

• .first returns (M) the first declared member
• .last returns (M) the last declared member

Note .first and .last are reserved "keywords" for state

Usage

from garnet.filters import group, State

class Users(group.Group):
    ask_name = group.M()
    ask_age = group.M()

    class Pet(group.Group):
        ask_name = group.M()
        ask_age = group.M()

    class Hobby(group.Group):
        frequency = group.M()
        ask_if_popular = group.M()

# 💫 just imagine we already have router 💫

@router.default(State.exact(Users))  # will handle all states in "Users"
# --- some code ---
@router.default(State.exact(Users.Pet.ask_age))  # will handle only if current state is equal to "Users.Pet.ask_age"
# --- some code ---

Note

Think of groups as an immutable(not really...) linked list of connected group members As you can see in the example above we use nested states groups. One thing about about M.[next/prev/top]. We can go to Users.Pet.ask_name from Users.ask_age using Users.ask_age.next, but not backwards as someone could expect with Users.Pet.ask_name.prev (will actually raise NoPrev) Nested group members do not know anything about upper members, but they have "owners" which have access to their parent groups and in order to access parent of owner of x = Users.Pet.ask_name, we would use x.owner

Callback query (QueryBaker)

Operations on callback queries. Baker is a callback_data string generator/parser/validator. garnet.ctx::Query has context value which is set after every successful validation.

Import

from garnet.filters import QueryBaker

Little journey

• (prefix:str, /, *args:str, [ignore:Iterable[QItem]=(),][sep:str="\n",][maxlen:int=64]) initializer function, if you want to have custom types in QueryDict
• .filter(extend_ignore:Iterable[str]=(), /, **config) will make sure user given callback data is valid by given config.
• .get_checked(**non_ignored:Any) will return a string based on passed passed args

Usage

from garnet.filters import QueryBaker

qb = QueryBaker(
    "v",  # set v string as identity(prefix) for our baker
    ("id", uuid.UUID),  # make uuid.UUID a factory for id arg
    "act",
    ignore=("id",),  # mark id arg as `optional`
    sep=":",  # set a separator for arg values, better not change
    maxlen=64,  # get_checked will check the length of generated callback and tell you if it's more than maxlen
)
# create v:{id}:{act} pattern

qb.filter(act="apply")
# will be a filter to match queries like "v:(.*):apply"

qb.get_checked(id="51b3f442-a9f6-4dcc-918e-1f08b1189386", act="clear")
# will produce a "safe" string pattern v:51b3f442-a9f6-4dcc-918e-1f08b1189386:clear

# Where you may want to use .get_checked
Button.inline(..., data=qb.get_checked(id=<...>, act="mpa"))

Note

Don't use separator string inside your arg values.

To reuse validated data from filter, use Query (validated dict)

Routers

Router (routing table) is a collection of handlers.

Public methods

Those consist mainly from decorators.

Initializer

Router(default_event=None, *filters)

• default_event default event builder for router
• *filters router filters, in order to get into handlers, event should pass these filters.

Decorators

Depending on event_builder of a decorator, filters inherit that event builder mutating themselves.

• .default(*filters) event builder is default Router(this, ...), should not be None, must implement telethon.common::EventBuilder
• .message(*filters) shortcut decorator for event builder garnet.events::NewMessage
• .callback_query(*filters) shortcut decorator for event builder garnet.events::CallbackQuery
• .chat_action(*filters) shortcut decorator for event builder garnet.events::ChatAction
• .message_edited(*filters) shortcut decorator for event builder garnet.events::MessageEdited
• .on(event_builder, /, *filters) pass any event builder (preferably from garnet.events::*)
• .use() use this decorator for intermediates that are called after filters

etc.

• .add_use(intermediate, /) register an intermediate which will be called after filters for handlers
• .register(handler, filters, event_builder) register handler with binding filters and event_builder to it.
• .include(router, /) "include" passed router in the callee as its child router

Examples

Simple cases

from garnet import Router, events, Filter

router = Router(events.NewMessage, Filter(lambda _: True), Filter(lambda _: True))

@router.default(Filter(lambda _: True))
async def handler(_): pass

Nested routers and a little intermediate

from my_project.routers import public_router, admin_router
from my_project.logging import put_event

from garnet import Router, events

common_router = Router().include(public_router).include(admin_router)

@common_router.use()
async def intermediate(handler, event):
    await put_event(event, nowait=True)
    await handler(event)

Context variables

Users states

from garnet.ctx import StateCtx, MCtx

MCtx is context variable that points to the current states group member (use it carefully) it's set in State filters

StateCtx points to garnet.event::UserCage

User and chat IDs

from garnet.ctx import UserIDCtx, ChatIDCtx

Those will be set after router filters and before handler filters and handlers calls.

Handler

from garnet.ctx import HandlerCtx

HandlerCtx points to currently executing handler.

Query (validated dict)

Data that is stored in Dict[str(arg name), T(arg type from arg-factory(arg-str)->T)]

from garnet.ctx import Query

Note

Usual contextual variables, with .get(), .set(), .reset() methods. You'll always end up using .get(). Work with those only in handlers or handler filters.

Also every event builder in garnet.events is "contextfull", but for get, set, reset you shall add _current postfix.

Try to use context variables everywhere not depending on other mechanisms, because they work as you want.

🦾 Hacking garnet

Garnet consists of two interfaces _garnet and garnet, garnet is a "public" interface that should have somewhat stable interfaces and _garnet which is internal and considered as non-public

Install and get started

git clone git@github.com:ukinti/garnet.git garnet
poetry install --dev
poetry shell

Applying code-style

# simply
make lint

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