# Module oc_stat_view # * [Description](#description) * [Data Types](#types) * [Function Index](#index) * [Function Details](#functions) View allows users to aggregate the recorded Measurements. ## Description ## Views need to be passed to the subscribe function to be before data will be collected and sent to exporters. ## Data Types ## ### description() ###


description() = binary() | string()

### name() ###


name() = atom() | binary() | string()

### view() ###


view() = #view{name = name() | _, measure = measure_name() | _, subscribed = boolean(), description = description() | _, ctags = oc_tags:tags() | _, tags = [oc_tags:key()] | _, aggregation = aggregation() | _, aggregation_options = aggregation_options() | _}

### view_data() ###


view_data() = #{name => name(), description => description(), ctags => oc_tags:tags(), tags => [oc_tags:key()], data => oc_stat_aggregation:data()}

## Function Index ##

'__init_backend__'/0
code_change/3
deregister/1	Deregisters the view.
export/1	Returns a snapshot of the View's data.
handle_call/3
handle_cast/2
handle_info/2
init/1
is_registered/1	Returns true if the view is registered.
is_subscribed/1	Returns true if the view is exporting data by subscription.
new/1	Creates a View from a map.
new/5	Creates a View.
preload/1	Loads and subscribes views from the `List` in one shot.
register/1	Registers the view.
register/5	Registers the view created from arguments.
start_link/0
subscribe/1	Subscribe the View, When subscribed, a view can aggregate measure data and export it.
subscribe/5	A shortcut.
terminate/2
unsubscribe/1	Unsubscribes the View.

## Function Details ## ### '__init_backend__'/0 ### `__init_backend__() -> any()` ### code_change/3 ### `code_change(OldVsn, State, Extra) -> any()` ### deregister/1 ###


deregister(View::name() | view()) -> ok

Deregisters the view. If subscribed, unsubscribes and therefore existing aggregation data cleared. ### export/1 ###


export(View::view()) -> view_data()

Returns a snapshot of the View's data. ### handle_call/3 ### `handle_call(X1, From, State) -> any()` ### handle_cast/2 ### `handle_cast(X1, State) -> any()` ### handle_info/2 ### `handle_info(X1, State) -> any()` ### init/1 ### `init(Args) -> any()` ### is_registered/1 ###


is_registered(View::name() | view()) -> boolean()

Returns true if the view is registered. ### is_subscribed/1 ###


is_subscribed(View::name() | view()) -> boolean()

Returns true if the view is exporting data by subscription. ### new/1 ### `new(Map) -> any()` Creates a View from a map. ### new/5 ### `new(Name, Measure, Description, Tags, Aggregation) -> any()` Creates a View. This view needs to be registered and subscribed to a measure in order to start aggregating data. ### preload/1 ### `preload(List) -> any()` Loads and subscribes views from the `List` in one shot. Usually used for loading views from configuration on app start. ### register/1 ###


register(View::view()) -> {ok, view()} | {error, any()}

Registers the view. Aggregation initialized with AggregationOptions. ### register/5 ### `register(Name, Measure, Description, Tags, Aggregation) -> any()` Registers the view created from arguments. ### start_link/0 ### `start_link() -> any()` ### subscribe/1 ###


subscribe(View::name() | view()) -> {ok, view()} | {error, any()}

Subscribe the View, When subscribed, a view can aggregate measure data and export it. ### subscribe/5 ### `subscribe(Name, Measure, Description, Tags, Aggregation) -> any()` A shortcut. Creates, Registers, and Subscribes a view in one call. ### terminate/2 ### `terminate(X1, X2) -> any()` ### unsubscribe/1 ###


unsubscribe(View::name() | view()) -> ok

Unsubscribes the View. When unsubscribed a view no longer aggregates measure data and exports it. Also all existing aggregation data cleared.