I am making a menu and submenus using recursion function and I am in the need of help to open only the respective menu and sub menu's..
For button and collapse Reactstrap has been used..
Recursive function that did menu population:
{this.state.menuItems &&
this.state.menuItems.map((item, index) => {
return (
<div key={item.id}>
<Button onClick={this.toggle.bind(this)}> {item.name} </Button>
<Collapse isOpen={this.state.isToggleOpen}>
{this.buildMenu(item.children)}
</Collapse>
</div>
);
})}
And the buildMenu function as follows,
buildMenu(items) {
return (
<ul>
{items &&
items.map(item => (
<li key={item.id}>
<div>
{this.state.isToggleOpen}
<Button onClick={this.toggle.bind(this)}> {item.name} </Button>
<Collapse isOpen={this.state.isToggleOpen}>
{item.children && item.children.length > 0
? this.buildMenu(item.children)
: null}
</Collapse>
</div>
</li>
))}
</ul>
);
}
There is no problem with the code as of now but I am in the need of help to make menu -> submenu -> submenu step by step open and closing respective levels.
Working example: https://codesandbox.io/s/reactstrap-accordion-9epsp
You can take a look at this example that when you click on any menu the whole level of menus gets opened instead of clicked one..
Requirement
If user clicked on menu One, then the submenu (children)
-> One-One
needs to get opened.
And then if user clicked on One-One,
-> One-One-One
-> One - one - two
-> One - one - three
needs to get opened.
Likewise it is nested so after click on any menu/ children their respective next level needs to get opened.
I am new in react and reactstrap way of design , So any help from expertise would be useful for me to proceed and learn how actually it needs to be done.
Instead of using one large component, consider splitting up your component into smaller once. This way you can add state to each menu item to toggle the underlying menu items.
If you want to reset al underlying menu items to their default closed position you should create a new component instance each time you open up a the underlying buttons. By having <MenuItemContainer key={timesOpened} the MenuItemContainer will be assigned a new key when you "open" the MenuItem. Assigning a new key will create a new component instance rather than updating the existing one.
For a detailed explanation I suggest reading You Probably Don't Need Derived State - Recommendation: Fully uncontrolled component with a key.
const loadMenu = () => Promise.resolve([{id:"1",name:"One",children:[{id:"1.1",name:"One - one",children:[{id:"1.1.1",name:"One - one - one"},{id:"1.1.2",name:"One - one - two"},{id:"1.1.3",name:"One - one - three"}]}]},{id:"2",name:"Two",children:[{id:"2.1",name:"Two - one"}]},{id:"3",name:"Three",children:[{id:"3.1",name:"Three - one",children:[{id:"3.1.1",name:"Three - one - one",children:[{id:"3.1.1.1",name:"Three - one - one - one",children:[{id:"3.1.1.1.1",name:"Three - one - one - one - one"}]}]}]}]},{id:"4",name:"Four"},{id:"5",name:"Five",children:[{id:"5.1",name:"Five - one"},{id:"5.2",name:"Five - two"},{id:"5.3",name:"Five - three"},{id:"5.4",name:"Five - four"}]},{id:"6",name:"Six"}]);
const {Component, Fragment} = React;
const {Button, Collapse} = Reactstrap;
class Menu extends Component {
constructor(props) {
super(props);
this.state = {menuItems: []};
}
render() {
const {menuItems} = this.state;
return <MenuItemContainer menuItems={menuItems} />;
}
componentDidMount() {
loadMenu().then(menuItems => this.setState({menuItems}));
}
}
class MenuItemContainer extends Component {
render() {
const {menuItems} = this.props;
if (!menuItems.length) return null;
return <ul>{menuItems.map(this.renderMenuItem)}</ul>;
}
renderMenuItem(menuItem) {
const {id} = menuItem;
return <li key={id}><MenuItem {...menuItem} /></li>;
}
}
MenuItemContainer.defaultProps = {menuItems: []};
class MenuItem extends Component {
constructor(props) {
super(props);
this.state = {isOpen: false, timesOpened: 0};
this.open = this.open.bind(this);
this.close = this.close.bind(this);
}
render() {
const {name, children} = this.props;
const {isOpen, timesOpened} = this.state;
return (
<Fragment>
<Button onClick={isOpen ? this.close : this.open}>{name}</Button>
<Collapse isOpen={isOpen}>
<MenuItemContainer key={timesOpened} menuItems={children} />
</Collapse>
</Fragment>
);
}
open() {
this.setState(({timesOpened}) => ({
isOpen: true,
timesOpened: timesOpened + 1,
}));
}
close() {
this.setState({isOpen: false});
}
}
ReactDOM.render(<Menu />, document.getElementById("root"));
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.4.1/css/bootstrap.min.css" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/reactstrap/8.4.1/reactstrap.min.js"></script>
<div id="root"></div>
You will want to create an inner component to manage the state at each level.
For example, consider the following functional component (I'll leave it to you to convert to class component):
const MenuButton = ({ name, children }) => {
const [open, setOpen] = useState(false);
const toggle = useCallback(() => setOpen(o => !o), [setOpen]);
return (
<>
<Button onClick={toggle}>{name}</Button>
<Collapse open={open}>{children}</Collapse>
</>
);
};
This component will manage whether to display its children or not. Use it in place of all of your <div><Button/><Collapse/></div> sections, and it will manage the open state for each level.
Keep shared state up at the top, but if you don't need to know whether something is expanded for other logic, keep it localized.
Also, if you do need that info in your parent component, use the predefined object you already have and add an 'open' field to it which defaults to false. Upon clicking, setState on that object to correctly mark the appropriate object to have the parameter of true on open.
Localized state is much cleaner though.
Expanded Example
import React, { Component, useState, useCallback, Fragment } from "react";
import { Collapse, Button } from "reactstrap";
import { loadMenu } from "./service";
const MenuButton = ({ name, children }) => {
const [open, setOpen] = React.useState(false);
const toggle = useCallback(() => setOpen(o => !o), [setOpen]);
return (
<Fragment>
<Button onClick={toggle}>{name}</Button>
<Collapse open={open}>{children}</Collapse>
</Fragment>
);
};
class Hello extends Component {
constructor(props) {
super(props);
this.state = {
currentSelection: "",
menuItems: [],
};
}
componentDidMount() {
loadMenu().then(items => this.setState({ menuItems: items }));
}
buildMenu(items) {
return (
<ul>
{items &&
items.map(item => (
<li key={item.id}>
<MenuButton name={item.name}>
{item.children && item.children.length > 0
? this.buildMenu(item.children)
: null}
</MenuButton>
</li>
))}
</ul>
);
}
render() {
return (
<div>
<h2>Click any of the below option</h2>
{this.state.menuItems &&
this.state.menuItems.map((item, index) => {
return (
<MenuButton name={item.name}>
{this.buildMenu(item.children)}
</MenuButton>
);
})}
</div>
);
}
}
export default Hello;
Related
New to React and trying to build a tabular component. I know I'm reinventing the wheel but I'm trying to take this as a learning experience.
Here is how I intend to use the component:
<Tabs>
<Tabs.MenuItems>
<Tabs.MenuItem>Tab item 1</Tabs.MenuItem>
<Tabs.MenuItem>Tab item 2</Tabs.MenuItem>
<Tabs.MenuItem>Tab item 3</Tabs.MenuItem>
<Tabs.MenuItem>Tab item 4</Tabs.MenuItem>
</Tabs.MenuItems>
<Tabs.Panes>
<Tabs.Pane><div>placeholder></div></Tabs.Pane>
<Tabs.Pane><div>placeholder></div></Tabs.Pane>
<Tabs.Pane><div>placeholder></div></Tabs.Pane>
<Tabs.Pane><div>placeholder></div></Tabs.Pane>
</Tabs.Panes>
</Tabs>
My current implementation works in displaying the items properly. But the one challenge I am facing is being able to handle the onClick event for the Tabs.MenuItem. I understand that I should not be handling the onClick in the Tabs.MenuItem child component, and rather should be handled in the upmost parent Tabs component.
I tried using forwardedRef but that posed some limitations in accessing the props.children. Even if I managed to get it working syntactically, I am not even sure how the Tabs component is suppose to access that ref.
The idea here is that depending on what Tabs.MenuItem is in an active state, it will correspond to the same child Tabs.Pane component index to render that pane.
import React, { forwardRef, useState } from "react";
const Tabs = (props, { activePane }) => {
return (
props.children
);
}
const MenuItems = (props) => {
React.Children.forEach(props.children, child => {
console.log(child);
})
return (
<div className="ui secondary menu" style={props.style}>
{props.children}
</div>
)
}
const MenuItem = (props) => {
const [isActive, setActive] = useState(false);
return (
// eslint-disable-next-line jsx-a11y/anchor-is-valid
<a className={isActive ? "item active" : "item"} onClick={() => setActive(!isActive)}>{props.children}</a>
)
}
// const MenuItem = forwardRef((props, ref) => (
// // eslint-disable-next-line jsx-a11y/anchor-is-valid
// <a ref={ref} className="item">{props.children}</a> // error accessing props.children
// ))
const Panes = (props) => {
return (
props.children
)
}
const Pane = (props) => {
return (
props.children
)
}
Tabs.MenuItems = MenuItems;
Tabs.MenuItem = MenuItem;
Tabs.Panes = Panes;
Tabs.Pane = Pane;
export default Tabs;
I am not looking for someone to complete the entire tabular functionality, just an example of how I can forward the children references to the topmost parent so that I can handle click events properly.
I have created a simple Todo list, adding item works but when I clicked on the 'delete' button, my Item is not deleting any item from the List. I would like to know what mistakes I am making in my code, Would appreciate all the help I could get. Thanks in Advance!
And ofcourse, I have tried Looking through google and Youtube, But just couldnot find the answer I am looking for.
Link: https://codesandbox.io/embed/simple-todolist-react-2019oct-edbjf
App.js:
import React from "react";
import ReactDOM from "react-dom";
import "./styles.css";
import TodoForm from "./TodoForm";
import Title from "./Title";
class App extends React.Component {
// myRef = React.createRef();
render() {
return (
<div className="App">
<Title />
<TodoForm />
</div>
);
}
}
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);
----------------------
TodoForm.js:
import React from "react";
import ListItems from "./ListItems";
class TodoForm extends React.Component {
constructor(props) {
super(props);
this.state = {
value: "",
items: [],
id: 0
};
}
inputValue = e => {
this.setState({ value: e.target.value });
};
onSubmit = e => {
e.preventDefault();
this.setState({
value: "",
id: 0,
items: [...this.state.items, this.state.value]
});
};
deleteItem = (itemTobeDeleted, index) => {
console.log("itemTobeDeleted:", itemTobeDeleted);
const filteredItem = this.state.items.filter(item => {
return item !== itemTobeDeleted;
});
this.setState({
items: filteredItem
});
};
// remove = () => {
// console.log("removed me");
// };
render() {
// console.log(this.deleteItem);
console.log(this.state.items);
return (
<div>
<form onSubmit={this.onSubmit}>
<input
type="text"
placeholder="Enter task"
value={this.state.value}
onChange={this.inputValue}
/>
<button>Add Item</button>
</form>
<ListItems items={this.state.items} delete={() => this.deleteItem} />
</div>
);
}
}
export default TodoForm;
----------------------
ListItems.js
import React from "react";
const ListItems = props => (
<div>
<ul>
{props.items.map((item, index) => {
return (
<li key={index}>
{" "}
{item}
<button onClick={props.delete(item)}>Delete</button>
</li>
);
})}
</ul>
</div>
);
export default ListItems;
The problem is, you must pass a function to the onDelete, but you are directly calling the function
updating the delete item like so,
deleteItem = (itemTobeDeleted, index) => (event) => {
and update this line, (since the itemTobeDeleted was not reaching back to the method)
<ListItems items={this.state.items} delete={(item) => this.deleteItem(item)} />
fixes the issue
Working sandbox : https://codesandbox.io/s/simple-todolist-react-2019oct-zt5w6
Here is the working example: https://codesandbox.io/s/simple-todolist-react-2019oct-xv3b5
You have to pass in the function into ListItems and in ListItems run it passing in the correct argument (the item).
Your solution is close; there are two fixes needed for your app to work as expected.
First, when rendering the ListItems component, ensure that the item is passed through to your deleteItem() function:
<ListItems items={this.state.items} delete={(item) => this.deleteItem(item)} />
Next, your ListItems component needs to be updated so that the delete callback prop is called after an onclick is invoked by a user (rather than immediatly during rendering of that component). This can be fixed by doing the following:
{ props.items.map((item, index) => {
return (<li key={index}>{item}
{/*
onClick is specified via inline callback arrow function, and
current item is passed to the delete callback prop
*/}
<button onClick={() => props.delete(item)}>Delete</button>
</li>);
)}
Here's a working version of your code sandbox
first make a delete function pass it a ind parameter and then use filter method on your array in which you saved the added values like
function delete(ind){
return array.filter((i)=>{
return i!==ind;
})
}
by doing this elements without the key which you tried to delete will not be returned and other elements will be returned.
Suppose I have two components which aren't nested: a button and a panel. When the button is clicked, the panel will show or hide depending on the previous state (like an on/off switch). They aren't nested components, so the structure looks like this:
<div>
<Toolbar>
<Button />
</Toolbar>
<Content>
...
<ButtonPanel />
</Content>
</div>
I can't change the structure of the DOM. I also can't modify any other component other than the button and panel components.
The Button and ButtonPanel components are related, however, and will be used together throughout the solution. I need to pass a property to the panel to let it know when to show or when to hide. I was thinking about doing it with Context API, but I think there's something I'm doing wrong and the property never updates.
This is my code:
Context
import React from 'react';
export const ButtonContext = React.createContext({
showPanel: false,
});
Button
import React, { Component } from 'react';
import { ButtonContext } from './ButtonContext';
class Button extends Component {
constructor() {
super();
this.state = {
showPanel: false,
};
}
render() {
return (
<ButtonContext.Provider value={{ showPanel: this.state.showPanel }}>
<li>
<a
onClick={() => this.setState({ showPanel: !this.state.showPanel }, () => console.log('Changed'))}
>
<span>Button</span>
</a>
</li>
</ButtonContext.Provider>
);
}
}
export { Button };
Panel
import React, { Component } from 'react';
import { Panel, ListGroup, ListGroupItem } from 'react-bootstrap';
import { ButtonContext } from './ButtonContext';
class ButtonPanel extends Component {
static contextType = ButtonContext;
render() {
return (
<ButtonContext.Consumer>
{
({ showPanel }) => {
if (showPanel) {
return (
<Panel id="tasksPanel">
<Panel.Heading >Panel Heading</Panel.Heading>
<ListGroup>
<ListGroupItem>No Items.</ListGroupItem>
</ListGroup>
</Panel>
);
}
return null;
}
}
</ButtonContext.Consumer>
);
}
}
export { ButtonPanel };
I've also tried simply accessing the context in the ButtonPanel component like so:
render() {
const context = this.context;
return context.showPanel ?
(
<Panel id="tasksPanel">
<Panel.Heading >Tasks</Panel.Heading>
<ListGroup>
<ListGroupItem className="tasks-empty-state">No tasks available.</ListGroupItem>
</ListGroup>
</Panel>
)
:
null;
}
What am I doing wrong?
Thanks
From the React docs:
Accepts a value prop to be passed to consuming components that are descendants of this Provider.
So this means that <ButtonContext.Provider> has to wrap <ButtonContext.Consumer> or it has to be higher up in the component hierarchy.
So based on your use case, you could do:
// This app component is the div that wraps both Toolbar and Content. You can name it as you want
class App extends Component {
state = {
showPanel: false,
}
handleTogglePanel = () => this.setState(prevState => ({ togglePanel: !prevState.togglePanel }));
render() {
return (
<ButtonContext.Provider value={{ showPanel: this.state.showPanel, handleTogglePanel: this.handleTogglePanel }}>
<Toolbar>
<Button />
</Toolbar>
<Content>
<ButtonPanel />
</Content>
</ButtonContext.Provider>
);
}
}
class Button extends Component {
...
<ButtonContext.Consumer>
{({ handleTogglePanel }) => <a onClick={handleTogglePanel} />}
</ButtonContext.Consumer>
}
class ButtonPanel extends Component {
...
<ButtonContext.Consumer>
{({ showPanel }) => showPanel && <Panel>...</Panel>}
</ButtonContext.Consumer>
}
I'm wondering how I can create a stateless component within a class. Like if I use these functions outside the class, my page renders, but when I put them in the class. My page doesn't render. I want them to be inside the class so I can apply some class props to them.
class helloClass extends React.Component {
state = {
};
Hello =({ items}) => {
return (
<ul>
{items.map((item, ind) => (
<RenderHello
value={item.name}
/>
))}
</ul>
);
}
RenderHello = ({ value }) => {
return (
<div>
{open && value && (
<Hello
value={value}
/>
)}
</div>
);
}
render() {
}
}
export default (helloClass);
I have a setup like this. But not actually like this. And I keep getting the error that Hello and RenderHello do not exist. However, if I turn these into functions outside of the class, they work and everything renders on my page. I just want to know how I can achieve the same but within a class. If that's even possible.
Several ways of doing it, but the cleanist is to separate the stateless functions into it's their own files and have a single container that handles state and props and passes them down to the children:
Hello.js (displays the li items)
import React from 'react';
export default ({ items }) => (
<ul>
{items.map((item, ind) => (
<li key={ind}>
{item.name}
</li>
))}
</ul>
);
RenderHello.js (only returns Hello if open and value are true)
import React from 'react';
import Hello from './Hello';
export default ({ open, value, items }) => (
open && value
? <Hello items={items} />
: null
);
HelloContainer.js (contains state and methods to update the children nodes)
import React, { Component } from 'react';
import RenderHello from './RenderHello';
class HelloContainer extends Component {
state = {
items: [...],
open: false,
value: ''
};
...methods that update the state defined above (ideally, these would be passed down and triggered by the child component defined below)
render = () => <RenderHello {...this.state} />
}
Its strange because you have a recursive call that will end up in a infinite loop, but syntactically, it would be something like that:
class helloClass extends React.Component {
state = {
};
Hello(items) {
return (
<ul>
{items.map((item, ind) => (
{this.RenderHello(item.name)}
))}
</ul>
);
}
RenderHello(value) {
return (
<div>
{open && value && (
{this.Hello(value)}
)}
</div>
);
}
render()
{
}
}
export default (helloClass);
I am pretty new to react and I have been stuck in a problem for quite a good time.
I have a component DisplayList that iterates through an array of objects and displays them in a list form. Each object becomes a button. I also have another component to render the single view of each item on the list once the item is clicked. My problem is that I get to render the single view of all my items at once INSIDE my displayList component. All I want is to be able to click on the list item and render another component with ONLY info about the item I clicked on and passing my "project" as the props to it. what should I do? What is my error?
My DisplayList component (the part that matters for this problem):
export default class DisplayList extends Component {
constructor() {
super();
this.state = {
displaySingle: false
};
}
handleClick = () => {
this.setState({
displaySingle: true
})
}
render() {
if (this.props.projects && this.props.projects.length > 0) {
return (
<List component="nav">
{this.props.projects.map(project => (
<div className="all-content-wrapper" key={project.id}>
<ListItem button value={project} onClick={this.handleClick}>
{this.state.displaySingle ?
<DisplaySingleItem project={project} /> :
null
}
<ListItemICon>
<img
className="single-item-img-in-list-view"
src={project.img}
/>
</ListItemICon>
You are just a hint away from doing it the right way:
Change the condition in your onClick() as:
onClick={()=>this.handleClick(project.id)}
{ this.state.displayProject_id === project.id ?
<DisplaySingleItem project={project} /> :
null
}
Now define handleClick() as:
handleClick = (project_id) => {
this.setState({
displayProject_id: project_id
})
}
Don't forget to define the initial state in the constructor:
this.state = {
displayProject_id:null
};
<div className="all-content-wrapper" key={project.id}>
<ListItem button value={project} onClick={()=>this.handleClick(project)}>
{this.state.displayProject && this.state.displayProject.id==project.id ?
<DisplaySingleItem project={project} /> :
null
}
<ListItemICon>
<img
className="single-item-img-in-list-view"
src={project.img}
/>
</ListItemICon>
</ListItem>
</div>
change your JSX like the above so you pass the current project to handleClick and change handleClick like the following.
handleClick = (project) => {
this.setState({
displayProject : project
})
}
It should now display the <DisplaySingleItem/> for the clicked project.
For you to be able to show only the project that was selected it is important that you have a reference to it. Right now your handleClick() function does not accept and parameters or data that you can identify the project that was selected.
My solution for you is to pass the project as a parameter to handleClick(project). So your code should look like.
export default class DisplayList extends Component {
constructor() {
super();
this.state = {
displaySingle: false
};
}
handleClick = (project) => {
this.setState({
selectedProject: project, // <- use this state to show your popup or
// whatever view you're using
displaySingle: true
})
}
render() {
if (this.props.projects && this.props.projects.length > 0) {
return (
<List component="nav">
{this.props.projects.map(project => (
<div className="all-content-wrapper" key={project.id}>
<ListItem button value={project} onClick={() => this.handleClick(project)}>
{this.state.displaySingle ?
<DisplaySingleItem project={project} /> :
null
}
<ListItemICon>
<img
className="single-item-img-in-list-view"
src={project.img}
/>
</ListItemICon>
)
}