Fork is from https://github.com/kilkelly/redux-localstorage-simple, used to support nextjs.
Save and load Redux state to and from LocalStorage.
npm install --save redux-localstorage-simple-next
or yarn, pnpm
import { applyMiddleware, createStore } from "redux";
import reducer from "./reducer";
// Import the necessary methods for saving and loading
import { save, load } from "redux-localstorage-simple-next";
/*
Saving to LocalStorage is achieved using Redux
middleware. The 'save' method is called by Redux
each time an action is handled by your reducer.
*/
const createStoreWithMiddleware = applyMiddleware(
save() // Saving done here
)(createStore);
/*
Loading from LocalStorage happens during
creation of the Redux store.
*/
const store = createStoreWithMiddleware(
reducer,
load() // Loading done here
);
Saving to LocalStorage is achieved using Redux middleware and saves each time an action is handled by your reducer. You will need to pass the save
method into Redux's applyMiddleware
method, like so...
applyMiddleware(save());
See the Usage Example above to get a better idea of how this works.
The save
method takes a optional configuration object as an argument. It has the following properties:
{
[Array states],
[Array ignoreStates]
[String namespace],
[String namespaceSeparator],
[Number debounce],
[Boolean disableWarnings]
}
- states (Array, optional) - This is an optional array of strings specifying which parts of the Redux state tree you want to save to LocalStorage. e.g. ["user", "products"]. Typically states have identical names to your Redux reducers. If you do not specify any states then your entire Redux state tree will be saved to LocalStorage.
- ignoreStates (Array, optional) - This is an optional array of strings specifying which parts of the Redux state tree you do not want to save to LocalStorage i.e. ignore. e.g. ["miscUselessInfo1", "miscUselessInfo2"]. Typically states have identical names to your Redux reducers. Unlike the
states
property,ignoreStates
only works on top-level properties within your state, not nested state as shown in the Advanced Usage section below e.g. "miscUselessInfo1" = works, "miscUselessInfo1.innerInfo" = doesn't work. - namespace (String, optional) - This is an optional string specifying the namespace to add to your LocalStorage items. For example if you have a part of your Redux state tree called "user" and you specify the namespace "my_cool_app", it will be saved to LocalStorage as "my_cool_app_user"
- namespaceSeparator (String, optional) - This is an optional string specifying the separator used between the namespace and the state keys. For example with the namespaceSeparator set to "::", the key saved to the LocalStorage would be "my_cool_app::user"
- debounce (Number, optional) - Debouncing period (in milliseconds) to wait before saving to LocalStorage. Use this as a performance optimization if you feel you are saving to LocalStorage too often. Recommended value: 500 - 1000 milliseconds
- disableWarnings (Boolean, optional) - Any exceptions thrown by LocalStorage will be logged as warnings in the JavaScript console by default, but can be silenced by setting
disableWarnings
to true.
Save entire state tree - EASIEST OPTION.
save();
Save specific parts of the state tree.
save({ states: ["user", "products"] });
Save entire state tree except the states you want to ignore.
save({ ignoreStates: ["miscUselessInfo1", "miscUselessInfo2"] });
Save the entire state tree under the namespace "my_cool_app". The key "my_cool_app" will appear in LocalStorage.
save({ namespace: "my_cool_app" });
Save the entire state tree only after a debouncing period of 500 milliseconds has elapsed
save({ debounce: 500 });
Save specific parts of the state tree with the namespace "my_cool_app". The keys "my_cool_app_user" and "my_cool_app_products" will appear in LocalStorage.
save({
states: ["user", "products"],
namespace: "my_cool_app",
});
Save specific parts of the state tree with the namespace "my_cool_app" and the namespace separator "::". The keys "my_cool_app::user" and "my_cool_app::products" will appear in LocalStorage.
save({
states: ["user", "products"],
namespace: "my_cool_app",
namespaceSeparator: "::",
});
Loading Redux state from LocalStorage happens during creation of the Redux store.
createStore(reducer, load());
See the Usage Example above to get a better idea of how this works.
The load
method takes a optional configuration object as an argument. It has the following properties:
{
[Array states],
[String namespace],
[String namespaceSeparator],
[Object preloadedState],
[Boolean disableWarnings]
}
- states (Array, optional) - This is an optional array of strings specifying which parts of the Redux state tree you want to load from LocalStorage. e.g. ["user", "products"]. These parts of the state tree must have been previously saved using the
save
method. Typically states have identical names to your Redux reducers. If you do not specify any states then your entire Redux state tree will be loaded from LocalStorage. - namespace (String, optional) - If you have saved your entire state tree or parts of your state tree with a namespace you will need to specify it in order to load it from LocalStorage.
- namespaceSeparator (String, optional) - If you have saved entire state tree or parts of your state tree with a namespaceSeparator, you will need to specify it in order to load it from LocalStorage.
- preloadedState (Object, optional) - Passthrough for the
preloadedState
argument in Redux'screateStore
method. See section Advanced Usage below. - disableWarnings (Boolean, optional) - When you first try to a load a state from LocalStorage you will see a warning in the JavaScript console informing you that this state load is invalid. This is because the
save
method hasn't been called yet and this state has yet to been written to LocalStorage. You may not care to see this warning so to disable it setdisableWarnings
to true. Any exceptions thrown by LocalStorage will also be logged as warnings by default, but can be silenced by settingdisableWarnings
to true.
Load entire state tree - EASIEST OPTION.
load();
Load specific parts of the state tree.
load({ states: ["user", "products"] });
Load the entire state tree which was previously saved with the namespace "my_cool_app".
load({ namespace: "my_cool_app" });
Load specific parts of the state tree which was previously saved with the namespace "my_cool_app".
load({
states: ["user", "products"],
namespace: "my_cool_app",
});
Load specific parts of the state tree which was previously saved with the namespace "my_cool_app" and namespace separator "::".
load({
states: ["user", "products"],
namespace: "my_cool_app",
namespaceSeparator: "::",
});
If you provided more than one call to save
in your Redux middleware you will need to use combineLoads
for a more intricate loading process.
- loads - This method takes any number of
load
methods as arguments, with each load handling a different part of the state tree. In practice you will provide oneload
method to handle eachsave
method provided in your Redux middleware.
Load parts of the state tree saved with different namespaces. Here are the save
methods in your Redux middleware:
applyMiddleware(
save({ states: ["user"], namespace: "account_stuff" }),
save({ states: ["products", "categories"], namespace: "site_stuff" })
);
The corresponding use of combineLoads
looks like this:
combineLoads(
load({ states: ["user"], namespace: "account_stuff" }),
load({ states: ["products", "categories"], namespace: "site_stuff" })
);
Clears all Redux state tree data from LocalStorage. Note: only clears data which was saved using this module's functionality
The clear
method takes a optional configuration object as an argument. It has the following properties:
{
[String namespace],
[Boolean disableWarnings]
}
- namespace - If you have saved your entire state tree or parts of your state tree under a namespace you will need to specify it in order to clear that data from LocalStorage.
- disableWarnings (Boolean, optional) - Any exceptions thrown by LocalStorage will be logged as warnings in the JavaScript console by default, but can be silenced by setting
disableWarnings
to true.
Clear all Redux state tree data saved without a namespace.
clear();
Clear Redux state tree data saved with a namespace.
clear({
namespace: "my_cool_app",
});
In a more complex project you may find that you are saving unnecessary reducer data to LocalStorage and would appreciate a more granular approach. Thankfully there is a way to do this.
First let's look at a normal example. Let's say you have a reducer called settings
and its state tree looks like this:
const settingsReducerInitialState = {
theme: "light",
itemsPerPage: 10,
};
Using redux-localstorage-simple
's save()
method for the settings
reducer would look like this:
save({ states: ["settings"] });
This saves all of the settings
reducer's properties to LocalStorage. But wait, what if we really only care about saving the user's choice of theme
and not itemsPerPage
. Here's how to fix this:
save({ states: ["settings.theme"] });
This saves only the theme
setting to LocalStorage. However this presents an additional problem, if itemsPerPage
is not saved won't my app crash when it can't find it upon loading from LocalStorage?
Yes in most cases it would. So to prevent this you can use the preloadedState
argument in the load()
method to provide some initial data.
load({
states: ["settings.theme"],
preloadedState: {
itemsPerPage: 10,
},
});
Also note in the above example that since settings.theme
was specified in the load()
method we must also mirror this exactly in the save()
method. This goes for all states you specify using the granular approach.
So if you have:
save({ states: ["settings.theme"] })
You must also have:
load({ states: ["settings.theme"] })
To run tests for this package open the file 'test/test.html' in your browser. Because this package uses LocalStorage we therefore need to test it in an environment which supports it i.e. modern browsers.
MIT