Redux: Better way for private/public selectors












1














As this course suggests, private selectors are repeated as public selectors to be used on the full state.




  • Private selectors used on slice.

  • Public selectors used on full state.


But this will result in:




  • Repeating code

  • Flooding the the namespace of the public selectors


Is there a better way to organize selectors?



Original example:



Root Reducer & public selector:



// reducers/index.js
import todos, * as fromTodos from './todos';

// Reducer
export default combineReducers({
todos
});

// Private selector
getVisibleTodos(state, filter) {
return fromTodos.getVisibleTodos(state.todos, filter);
}


Slice Reducer & private selector:



// reducers/todos.js

// Reducer
export default (state, action) => {
switch(action.type){
case 'ADD_TODO':
// ...
break;
// Handle other actions ...
}
}

// Private selector
getVisibleTodos(state, filter) {
switch(filter) {
case 'all':
return todos;
case 'completed':
return state.filter(t => t.completed);
// Other cases ...
}
}


Using the selector:



const mapStateToProps = (state, {params}) => ({
todos: getVisibleTodos(state, params.filter || 'all')
});









share|improve this question
























  • Can you provide a working example?
    – David Lemon
    Nov 13 '18 at 10:00










  • I've enhanced the example. Notice redefining the selector once as private selector and another time as a public selector. The question is about avoiding this repetition.
    – Meena Alfons
    Nov 13 '18 at 10:15






  • 1




    Selectors are usually pure functions so can be moved to their own module without issue. For inspiration I'd look at reselect
    – Davin Tryon
    Nov 13 '18 at 10:22
















1














As this course suggests, private selectors are repeated as public selectors to be used on the full state.




  • Private selectors used on slice.

  • Public selectors used on full state.


But this will result in:




  • Repeating code

  • Flooding the the namespace of the public selectors


Is there a better way to organize selectors?



Original example:



Root Reducer & public selector:



// reducers/index.js
import todos, * as fromTodos from './todos';

// Reducer
export default combineReducers({
todos
});

// Private selector
getVisibleTodos(state, filter) {
return fromTodos.getVisibleTodos(state.todos, filter);
}


Slice Reducer & private selector:



// reducers/todos.js

// Reducer
export default (state, action) => {
switch(action.type){
case 'ADD_TODO':
// ...
break;
// Handle other actions ...
}
}

// Private selector
getVisibleTodos(state, filter) {
switch(filter) {
case 'all':
return todos;
case 'completed':
return state.filter(t => t.completed);
// Other cases ...
}
}


Using the selector:



const mapStateToProps = (state, {params}) => ({
todos: getVisibleTodos(state, params.filter || 'all')
});









share|improve this question
























  • Can you provide a working example?
    – David Lemon
    Nov 13 '18 at 10:00










  • I've enhanced the example. Notice redefining the selector once as private selector and another time as a public selector. The question is about avoiding this repetition.
    – Meena Alfons
    Nov 13 '18 at 10:15






  • 1




    Selectors are usually pure functions so can be moved to their own module without issue. For inspiration I'd look at reselect
    – Davin Tryon
    Nov 13 '18 at 10:22














1












1








1







As this course suggests, private selectors are repeated as public selectors to be used on the full state.




  • Private selectors used on slice.

  • Public selectors used on full state.


But this will result in:




  • Repeating code

  • Flooding the the namespace of the public selectors


Is there a better way to organize selectors?



Original example:



Root Reducer & public selector:



// reducers/index.js
import todos, * as fromTodos from './todos';

// Reducer
export default combineReducers({
todos
});

// Private selector
getVisibleTodos(state, filter) {
return fromTodos.getVisibleTodos(state.todos, filter);
}


Slice Reducer & private selector:



// reducers/todos.js

// Reducer
export default (state, action) => {
switch(action.type){
case 'ADD_TODO':
// ...
break;
// Handle other actions ...
}
}

// Private selector
getVisibleTodos(state, filter) {
switch(filter) {
case 'all':
return todos;
case 'completed':
return state.filter(t => t.completed);
// Other cases ...
}
}


Using the selector:



const mapStateToProps = (state, {params}) => ({
todos: getVisibleTodos(state, params.filter || 'all')
});









share|improve this question















As this course suggests, private selectors are repeated as public selectors to be used on the full state.




  • Private selectors used on slice.

  • Public selectors used on full state.


But this will result in:




  • Repeating code

  • Flooding the the namespace of the public selectors


Is there a better way to organize selectors?



Original example:



Root Reducer & public selector:



// reducers/index.js
import todos, * as fromTodos from './todos';

// Reducer
export default combineReducers({
todos
});

// Private selector
getVisibleTodos(state, filter) {
return fromTodos.getVisibleTodos(state.todos, filter);
}


Slice Reducer & private selector:



// reducers/todos.js

// Reducer
export default (state, action) => {
switch(action.type){
case 'ADD_TODO':
// ...
break;
// Handle other actions ...
}
}

// Private selector
getVisibleTodos(state, filter) {
switch(filter) {
case 'all':
return todos;
case 'completed':
return state.filter(t => t.completed);
// Other cases ...
}
}


Using the selector:



const mapStateToProps = (state, {params}) => ({
todos: getVisibleTodos(state, params.filter || 'all')
});






javascript redux react-redux






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 13 '18 at 10:14







Meena Alfons

















asked Nov 13 '18 at 8:47









Meena AlfonsMeena Alfons

5231626




5231626












  • Can you provide a working example?
    – David Lemon
    Nov 13 '18 at 10:00










  • I've enhanced the example. Notice redefining the selector once as private selector and another time as a public selector. The question is about avoiding this repetition.
    – Meena Alfons
    Nov 13 '18 at 10:15






  • 1




    Selectors are usually pure functions so can be moved to their own module without issue. For inspiration I'd look at reselect
    – Davin Tryon
    Nov 13 '18 at 10:22


















  • Can you provide a working example?
    – David Lemon
    Nov 13 '18 at 10:00










  • I've enhanced the example. Notice redefining the selector once as private selector and another time as a public selector. The question is about avoiding this repetition.
    – Meena Alfons
    Nov 13 '18 at 10:15






  • 1




    Selectors are usually pure functions so can be moved to their own module without issue. For inspiration I'd look at reselect
    – Davin Tryon
    Nov 13 '18 at 10:22
















Can you provide a working example?
– David Lemon
Nov 13 '18 at 10:00




Can you provide a working example?
– David Lemon
Nov 13 '18 at 10:00












I've enhanced the example. Notice redefining the selector once as private selector and another time as a public selector. The question is about avoiding this repetition.
– Meena Alfons
Nov 13 '18 at 10:15




I've enhanced the example. Notice redefining the selector once as private selector and another time as a public selector. The question is about avoiding this repetition.
– Meena Alfons
Nov 13 '18 at 10:15




1




1




Selectors are usually pure functions so can be moved to their own module without issue. For inspiration I'd look at reselect
– Davin Tryon
Nov 13 '18 at 10:22




Selectors are usually pure functions so can be moved to their own module without issue. For inspiration I'd look at reselect
– Davin Tryon
Nov 13 '18 at 10:22












0






active

oldest

votes











Your Answer






StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53277038%2fredux-better-way-for-private-public-selectors%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Stack Overflow!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53277038%2fredux-better-way-for-private-public-selectors%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

Xamarin.iOS Cant Deploy on Iphone

Glorious Revolution

Dulmage-Mendelsohn matrix decomposition in Python