ReactiveShinyObject: Class: ReactiveShinyObject

In rappster/reactr: Reactive object bindings with built-in caching and push functionality

Description

Class that implements major parts of the reactivity mechanism of this package.

Usage

ReactiveShinyObject

Format

Class 'R6ClassGenerator' <environment: 0x000000000870dd58> 
 - attr(*, "name")= chr "ReactiveShinyObject_generator"

Details

Extends class shiny::Observable, or, to be more precise its clone ReactrObservable.

Fields

.cache

logical. TRUE: use caching mechanism and everything associated with it; FALSE: no caching. Initial: TRUE.

.caller

environment. Referenced environment corresponding to instance of SetShinyReactive that calls a reference (which can also be the object itself). Very important in order to fine tune update processes for bi-directional bindings. Default: self (after initialization).

.checksum

character. Checksum of visible object value. Initial: character().

.class

character. Class of visible object value (.value). If strongly typed (argument typed = TRUE in setShinyReactive, then this field is used to determine if an assignment value is valid or not. Initial: character().

condition

condition (at least by inheritance). If a condition has been signaled, this field is assigned a respective custom condition object that is triggered when the visible object value (or self$.value) is requested. Also see signalCondition and signalCondition Initial: NULL.

.id

character. Object ID. Initial: character().

.refs_checksum

environment. Environment for storing the cached checksums of pull references. Initial: new.env(parent = emptyenv()).

.refs_pull

environment. Environment for storing information of inbound/pull references. Initial: new.env(parent = emptyenv()).

.refs_push

environment. Environment for storing information of outbound/push references. Initial: new.env(parent = emptyenv()).

.registry

environment. Reference to the registry environment (see getRegistry. Important for retrieving and comparing checksum values, enabling push and other useful things (integrity checks etc.) Initial: getRegistry().

.uid

character. Object ID. Initial: character(). Automatically computed once .id is specified: digest::digest(list(id = .id, where = capture.output(eval(.where)))).

.where

environment. Environment of reactive object. Initial: parent.frame().

.exists_visible

logical. Field for tracking if the visible object value actually exists already or if this is a mere "empty container" in the registry. It is set to TRUE when the visible object is actually set/created via setShinyReactive. Initial: FALSE.

.has_bidir

logical. Field for signaling that an instance has bi-directional references to other objects. Very important in order to carry out updates for bi-directional bindings correctly. A system-wide check for the existence of bi-directional references is run via $.hasBidirectional inside setShinyReactive. The field is set to TRUE if there are any, else it remains FALSE. Initial: FALSE.

.has_cached

logical. Field for tracking if the instance already has a cached value or not. If FALSE, the binding function (if there is any) is executed and after that the field is set to TRUE to signal that a cached value exists. Initial: FALSE.

.has_pull_refs

logical. TRUE: instance has inbound/pull references; FALSE: instance has no inbound/pull references Initial: FALSE.

.has_push_refs

logical. TRUE: instance has outbound/push references; FALSE: instance has no outbound/push references Initial: FALSE.

.has_pushed

logical. TRUE: change has been pushed to all push references; FALSE: change has not been pushed to push references yet. Initial: FALSE.

.is_modcycle_complete

logical. TRUE: modification cycle complete; FALSE: modification cycle not complete yet. Only relevant for bi-directional bindings and in case of explicitly changing visible object values via <- or assign. Very important to determine the scope of object updates. Initial: TRUE.

.is_invalid

logical. Field for propagating the invalidity of referenced objects to its referencees. It is set to TRUE when an reactive object is unset or removed. Initial: FALSE.

.is_running_push

logical. TRUE: push process is currently running; FALSE: no push process is currently running. Initial: FALSE.

.must_push

logical. Field that controls if push is enabled. TRUE: push changes to outbound/push references; FALSE: changes need to be pulled by objects referencing this instance, no push. Initial: FALSE.

.needs_update

logical. Field that controls if update is to be carried out. TRUE: update; FALSE: no update, use cached value Initial: TRUE (in order to trigger initialization).

Author(s)

Janko Thyson [e-mail]

References

http://github.com/Rappster/reactr

See Also

ReactiveShinyObject, setShinyReactive, reactive, makeReactiveBinding, setReactive

Examples

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## TODO: add example


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rappster/reactr documentation built on May 26, 2019, 11:56 p.m.