redux-saga-selector-channel
Create a redux-saga channel which updates with changes to a selector function.
Example Usage
;;; // ... { // Use `selectorOutput` here, yield effects, do whatever you do in a saga!} // ... { const chan = ; ;} // ...
API
selectorChannel
(default export)
This package exports a single function which takes one or two arguments. The first argument is a selector function which will be passed the state of the redux store. The second argument is an optional buffer.
This function returns a call
effect which must be yield
ed to the
redux-saga runtime. The result will be a channel you can use in the same
way as any other redux-saga channel. The contents of the channel will consist of each new output from the
selector function (determined with ===
).
WARNING
Do not yield any effects from any saga which is handling output from your selector which will cause the selector to create a new output! This will cause an infinite loop. For a concrete example, consider the following:
// DO NOT DO THIS! { ;} { const chan = ; ;}
The selector function in this case returns the current counter
value and the
saga running in response to the selector output changing itself put
s an event
which changes the counter
value. This causes an infinite loop! It is okay to
put
from a selector response saga, but you have to be careful not to cause
infinite loops.
A Note on Build Systems
This package uses non-transpiled generator functions in order to give you the
flexibility to either use native generator functions or transpile them
yourself. If you need to support browsers that do not natively support
generator functions, make sure you configure your build to transpile this
package! In a setup using webpack the easiest way to do this is to use
Rule.include
and explitily include your source directories as well as the
resolved path to this module (rather than using Rule.exclude
to exclude
node_modules
and then somehow excluding this package from Rule.exclude
).
This package also doesn't have a main
field, only a module
field. As long
as you are using a modern build system this should not be a problem.
Prior Art
This package is simply a TypeScript packaging of
redux-saga/redux-saga#1694
. There may be future changes to support
passing additional arguments to the selector function (as is already supported
in the select
effect). Pull requests welcome!
License
MIT