how to get callback from child to parent class in react-redux? - reactjs

Question

I have to render few tabs. ONclick of it, it should get highlighted. I have tabList object coming from reducer (hard-coded value). onclicking of a tab a action is generated which set the "state" with clicked tab object(I call it "activeTab").
while rendering the tabList (all the tabs) I am checking if "rendered_tabid == active_tabid" then add a class "active" (it is conditional basis)
active-tab-reducer.js
export const tabReducer = () => {
return [
{
id: 1,
name:"Dental Page",
url: '#dentalPage'
},
{
id: 2,
name:"Vision Page",
url: '#visionPage'
},
{
id: 3,
name:"Other page Tab",
url: '#OtherPage'
}
]
}
const activeTabReducer = (state = {}, action) => {
switch(action.type) {
case "TAB_SELECTED": return action.payload;
break;
}
return state;
}
export default activeTabReducer;
(combined-reducer) index.js
import {combineReducers} from 'redux';
import activeTabReducer, {tabReducer} from './active-tab-reducer';
const allReducers = combineReducers({
tabList: tabReducer,
activeTab: activeTabReducer
});
export default allReducers;
(action) index.js
export const selectTab = (tab) => {
console.log('action invoked', tab);
return {
type: "TAB_SELECTED",
payload: tab
}
}
tablist.js
import React from 'react';
import {connect} from 'react-redux';
import {bindActionCreators} from 'redux';
import {selectTab} from '../actions/index';
import TabsListItem from './tabsListItem';
class TabList extends React.Component {
constructor(props){
super(props);
}
createTabItems(){
return this.props.tabList.map((item, i) => {
return (
<TabsListItem key={i} tabList={item} />
)
});
}
render() {
return (
<div id="layout-header" className="layout-header">
<div id="header" className="header">
<ul className="tabs tabs--horizontal">
{this.createTabItems()}
</ul>
</div>
</div>
);
}
};
function mapStateToProps(state) {
return {
tabList: state.tabList,
activeTab: state.activeTab
}
}
function matchDispatchToProps(dispatch){
return bindActionCreators({selectTab: selectTab}, dispatch);
}
export default connect(mapStateToProps, matchDispatchToProps)(TabList);
tabListItem.js
import React from 'react';
class TabListItem extends React.Component {
constructor(props){
super(props);
console.log(this.props.tabList)
}
render() {
return (
<li onClick={() => this.props.selectTab(this.props.tabList)}
className={"tab "+((this.props.activeTab.id==item.id)?'active':'')+""+( (this.props.activeTab.id==undefined) && (item.id == 1)?'active':'' )
role="presentation" className={"tab " }>
<a href="#">
<div className="tab__label">
<div className="tab__label__value">{this.props.tabList.name}</div>
</div>
</a>
</li>
);
}
};
export default TabListItem;
when I click any tab (from tabListItem), a action TAB_SELECTED action should dispatch, which set the state with "activeTab" object.
How to generate action from child?

Answer 1

You should pass a function to the child component via props.
As the action has a parameter to select the correct tab, you can use a function returning a function:
createTabItems() {
return this.props.tabList.map((item, i) => {
return (
<TabsListItem key={i} tabList={item} onSelect={() => this.onSelect(i).bind(this)} />
);
});
}
In this way your child component calls your method onSelect passing the correct parameter.
In your onSelect method on the parent (container) component you will then dispatch your action:
onSelect(i) {
this.props.selectTab(i);
}