Note: logger must be the last middleware in chain, otherwise it will log thunk and promise, not actual actions (#20).
Options
{ predicate,// if specified this function will be called before each action is processed with this middleware. collapsed, // takes a Boolean or optionally a Function that receives `getState` function for accessing current store state and `action` object as parameters. Returns `true` if the log group should be collapsed, `false` otherwise.
duration = false: Boolean,// print the duration of each action? timestamp = true: Boolean,// print the timestamp with each action? level ='log': 'log'|'console'|'warn'|'error'|'info',// console's level colors: ColorsObject, // colors for title, prev state, action and next state: https://github.com/evgenyrodionov/redux-logger/blob/master/src/defaults.js#L12-L18
titleFormatter,// Format the title used when logging actions. stateTransformer,// Transform state before print. Eg. convert Immutable object to plain JSON. actionTransformer,// Transform action before print. Eg. convert Immutable object to plain JSON. errorTransformer,// Transform error before print. Eg. convert Immutable object to plain JSON. logger = console: LoggerObject,// implementation of the `console` API. logErrors = true: Boolean,// should the logger catch, log, and re-throw errors? diff = false: Boolean,// (alpha) show diff between states? diffPredicate // (alpha) filter function for showing states diff, similar to `predicate`}
It can be a function (action: Object) => level: String.
It can be an object with level string for: prevState, action, nextState, error
It can be an object with getter functions: prevState, action, nextState, error. Useful if you want to print message based on specific state or action. Set any of them to false if you want to hide it.
Object with color getter functions: title, prevState, action, nextState, error. Useful if you want to paint message based on specific state or action. Set any of them to false if you want to show plain message without colors.
Implementation of the console API. Useful if you are using a custom, wrapped version of console.
Default: console
logErrors (Boolean)
Should the logger catch, log, and re-throw errors? This makes it clear which action triggered the error but makes "break on error" in dev tools harder to use, as it breaks on re-throw rather than the original throw location.
Takes a boolean or optionally a function that receives getState function for accessing current store state and action object as parameters. Returns true if the log group should be collapsed, false otherwise.
If specified this function will be called before each action is processed with this middleware. Receives getState function for accessing current store state and action object as parameters. Returns true if action should be logged, false otherwise.
Default: null (always log)
stateTransformer = (state: Object) => state
Transform state before print. Eg. convert Immutable object to plain JSON.
Default: identity function
actionTransformer = (action: Object) => action
Transform action before print. Eg. convert Immutable object to plain JSON.
Default: identity function
errorTransformer = (error: Any) => error
Transform error before print.
Default: identity function
titleFormatter = (action: Object, time: String?, took: Number?) => title
Format the title used for each action.
Default: prints something like action @ ${time} ${action.type} (in ${took.toFixed(2)} ms)