Redux - pass ownProps argument to selector - redux

Question

I cannot pass variable ownProps from mapStateToProps to selector. My selector:
export const nameSelector = createSelector(
[
state => state.element.get('name')
],
(name) => !name.trim()
);
const mapStateToProps = (state, ownProps) => ({
disabledAfterSave: nameSelector(state)
});
And I need to have a selector:
export const nameSelector = createSelector(
[
state => state.element.get('name')
],
(name, ownProps) => !name.trim() && ownProps.showMessage
);
const mapStateToProps = (state, ownProps) => ({
disabledAfterSave: nameSelector(state, ownProps)
});
But now I get an error: ReferenceError: ownProps is not defined.
When I tried to pass it like below:
export const nameSelector = (ownProps) => createSelector(
[
state => state.element.get('name')
],
(name) => !name.trim() && ownProps.showMessage
);
the returned type is not bool but [Function selector].
How can I pass this argument to my selector?

Answer 1

Here's how to fix your selector and its usage:
export const nameSelector = createSelector(
[
state => state.element.get('name'),
(state, ownProps) => ownProps.showMessage
],
(name, showMessage) => !name.trim() && ownProps.showMessage
)
const mapStateToProps = (state, ownProps) => ({
disabledAfterSave: nameSelector(state, ownProps)
})
Here's a generic working example, in order to illustrate how you can pass props down to the selector:
const createSelector = Reselect.createSelector
// Selector: Get Active Users
const getUsers = createSelector([state => state.users], users => users.filter(u => u.active))
// Selector: Get Active Users by Country
// Here you can check how I pass the country prop
const getUsersByCountry = createSelector([getUsers, (state, props) => props.country],
(users, country) => users.filter(u => u.country === country))
// The state
const state = {
users: [
{ id: 1, name: 'Jordan', country: 'Bulgaria', active: true},
{ id: 2, name: 'Nadezhda', country: 'Bulgaria', active: true},
{ id: 3, name: 'Hristo', country: 'Bulgaria', active: false},
{ id: 4, name: 'Bobby', country: 'England', active: true},
{ id: 5, name: 'Kaloyan', country: 'Germany', active: true},
]
}
// Testing
console.log(getUsers(state))
console.log(getUsersByCountry(state, { country: 'Bulgaria' }))
<script src="https://cdnjs.cloudflare.com/ajax/libs/reselect/3.0.1/reselect.min.js"></script>