Usage of Redux Form Fields component inside a FieldArray component - redux-form

Question

I have a Fields component that I am trying to use sometimes by itself and sometimes from inside a FieldArray component. I have added a snippet below with a simplified model.
import React from 'react';
import ReactDOM from 'react-dom';
import { createStore, combineReducers } from 'redux';
import { Provider } from 'react-redux';
import { reduxForm, Fields, FieldArray, reducer as formReducer } from 'redux-form';
const reducers = {
form: formReducer
};
const reducer = combineReducers(reducers);
const store = createStore(reducer);
const renderSharedComponent = (fields) => {
console.log(fields);
return (<div>Shared Component</div>);
};
const renderHashes = ({ fields }) => (
<div>
{
fields.map((field) => (
<Fields
key={ field }
names={ [`${field}.value`, `${field}.valueIsRegex`] }
component={ renderSharedComponent }
/>
))
}
</div>
);
const ReactComponent = () => (
<div>
<FieldArray
name="hashes"
component={ renderHashes }
/>
<Fields
names={ ['value', 'valueIsRegex'] }
component={ renderSharedComponent }
/>
</div>
);
const ReduxForm = reduxForm({
form: 'default',
initialValues: {
hashes: [{}]
}
})(ReactComponent);
ReactDOM.render((
<div>
<Provider store={ store }>
<ReduxForm />
</Provider>
</div>
), document.getElementById('content'));
When I use the Fields component by itself, the fields argument from inside renderSharedComponent has the following form:
{
value: { input: {...}, meta: {...} },
valueIsRegex: { input: {...}, meta: {...} },
names: [ 'value' , 'valueIsRegex' ]
}
When I use the Fields component inside a FieldArray component, the fields argument from inside renderSharedComponent has the following form:
{
hashes: [
{
value: { input: {...}, meta: {...} },
valueIsRegex: { input: {...}, meta: {...} }
}
],
names: [ 'hashes[0].value' , 'hashes[0].valueIsRegex' ]
}
If I will be using the Fields component inside a FieldArray component with a different name (let's say paths) the names property will change accordingly (eg. names: [ 'paths[0].value' , 'paths[0].valueIsRegex' ]).
I am trying to get the value and valueIsRegex objects in a generic way that will support any of the cases I presented above.
Right now I have created a function where I use a RegEx to determine the fields. But I was wondering if anyone knows a better way to do this (maybe there is a Redux Form util that maybe I missed when reading the documentation).

Answer 1

having the same problem. It may be that the idiomatic way is to use the formValueSelector function. But that way its a bit more boilerplate, as you have to pass the selector (as far as I understood it) all the way down through the form.
Personally I did the regexp-based function as well. Here it is:
/**
* Converts path expression string to array
* #param {string} pathExpr path string like "bindings[0][2].labels[0].title"
* #param {Array<string|int>} array path like ['bindings', 0, 2, 'labels', 0, 'title']
*/
function breakPath(pathExpr) {
return pathExpr
.split(/\]\.|\]\[|\[|\]|\./)
.filter(x => x.length > 0)
.map(x => isNaN(parseInt(x)) ? x : parseInt(x));
}
/**
* Executes path expression on the object
* #param {string} pathExpr – path string like "bindings[0][2].labels[0].title"
* #param {Object|Array} obj - object or array value
* #return {mixed} a value lying in expression path
* #example
* ```
* execPath('books[0].title', {books: [{title: 'foo'}]})
* // yields
* 'foo'
* ```
*/
function execPath(pathExpr, obj) {
const path = breakPath(pathExpr);
if (path.length < 1) {
return obj;
}
return path.reduce(function(obj, pathPart) {
return obj[pathPart];
}, obj);
}
/**
* A generic GroupLabelField that relies on valueBasePath
*/
const GroupLabelField = (props) => {
const groupData = execPath(props.valueBasePath, props);
return (
<div className={`label__content label__content_icon_${groupData.objectType.input.value}`}>
<span className="label__remove"
onClick={(e) => { props.handleRemove(); e.stopPropagation(); }}
>
<i className="material-icons material-icons_12 material-icons_top"></i>
</span>
<span className="label__text">{groupData.title.input.value}</span>
</div>
);
};

Answer 2

redux-form has a hidden utility function which is useful here, but I don't know if you can rely on it's availability in future versions:
import structure from "redux-form/lib/structure/plain";
function RenderRow({ names, ...props }) {
const fields = {};
names.forEach(n => (fields[n] = structure.getIn(props, n)));
}
See also this github issue