Unable to pass props to child component in react - javascript

I'm still getting to grips with react but I can't see why this isn't working, it should be passing the props from tabs into <Tab /> and outputting the button each time.
If I put no text next to {this.props.content} it doesn't display anything, if I put testText next to {this.props.content} it will output the button 5 times but only display testText not the name field it should be displaying via the content={item.name} prop
class TopCategories extends React.Component {
render() {
const Tab = () => (
<TestBtn key={this.props.key} >
testText {this.props.content}
</TestBtn>
)
const items = [
{ id: 1, name: 'tab-1', text: 'text' },
{ id: 2, name: 'tab-2', text: 'text' },
{ id: 3, name: 'tab-3', text: 'text' },
{ id: 4, name: 'tab-4', text: 'text' },
{ id: 5, name: 'tab-5', text: 'text' },
]
const tabs = items.map(item =>
<Tab key={item.id} content={item.name} />,
)
return (
<Container>
<Wrapper>
{tabs}
</Wrapper>
</Container>
)
}
}
export default TopCategories

You need to pass props to the stateless function and since it's a stateless component, this is not available. It should be something like:
const Tab = (props) => {
return (
<TestBtn key={props.key} >
testText {props.content}
</TestBtn>
);
}

Related

Material UI - Chip Array

I am writing some code for a ReactJS component to have an array of chips. I want each chip to be styled uniquely, so I set up a makeStyles class for each one. I was having trouble trying to figure out how to change the class for each tag. This is what I got so far:
const classes = useStyles();
const [chipData, setChipData] = React.useState([
{ key: 0, label: 'Heating' },
{ key: 1, label: 'Printing' },
{ key: 2, label: 'Resetting' },
{ key: 3, label: 'Idle' },
{ key: 4, label: 'Suspended' },
{ key: 5, label: 'Suspend in Progress' },
{ key: 6, label: 'Attention - Printer Connection Lost' },
{ key: 7, label: 'Attention - Filament Out' },
{ key: 8, label: 'Attention - Cooldown Failed' },
]);
return (
<Box display="flex" flexDirection="row" alignItems="flex-start" className={classes.container}>
{chipData.map((data) => {
return (
<div classes={classes.chipContainer}>
<li key={data.key}>
<Chip
label={data.label}
if (label === 'Heating') {
className={classes.heatingTag}
}
/>
</li>
</div>
);
})}
</Box>
);
}
export default PrinterStatusTags
So within the chip element, I have an if statement that is used to assign a specific class based on the label. My plan was to have an if statement for each label, but I am getting the following error:
Parsing error: Unexpected token
Any ideas how I can assign a class based on the chip?
Updated Answer
I would 2 things:
Add a new type property for every chip.
Create a mapper from the type (in the 1st point) to the classes
const classesMapper = {
first: classes.firstClass,
second: classes.secondClass
// ...
};
const [chipData, setChipData] = React.useState([
{ key: 0, label: 'Heating', type: 'first' },
{ key: 1, label: 'Printing', type: 'seocnd' },
// ....
]);
After you have the mapping between every chip to its type. Just render it:
return (
<Box display="flex" flexDirection="row" alignItems="flex-start" className={classes.container}>
{chipData.map((data) => {
return (
<div classes={classes.chipContainer}>
<li key={data.key}>
<Chip
label={data.label}
className={classesMapper[data.type]} />
</li>
</div>
);
})}
</Box>
);
Old Answer
You should write the code a little bit different:
Use className property and not the property class (nor classes)
Set the condition inside the className property. Please note that there are better ways to set the right class but for your case, that would be good enough.
This is the code as it should be:
<div classeName={classes.chipContainer}>
<li key={data.key}>
<Chip label={data.label} className={ label ==== 'Heating' && classes.heatingTag}/>
</li>
</div>

ReactJS How to use Refs on components rendered dinamically by another render function to focus elements?

I have a class component that Renders a list of elements and I need to focus them when an event occurs.
Here is an example code
class page extends React.Component {
state = {
items: [array of objects]
}
renderList = () => {
return this.state.items.map(i => <button>{i.somekey}</button>)
}
focusElement = (someitem) => {
//Focus some item rendered by renderList()
}
render(){
return(
<div>
{this.renderList()}
<button onClick={() => focusElement(thatElement)}>
</div>
)
}
}
I know that I need to use refs but I tried several ways to do that and I couldn't set those refs properly.
Can someone help me?
you should use the createRefmethod of each button that you would like to focus, also you have to pass this ref to the focusElement method that you have created:
const myList = [
{ id: 0, label: "label0" },
{ id: 1, label: "label1" },
{ id: 2, label: "label2" },
{ id: 3, label: "label3" },
{ id: 4, label: "label4" },
{ id: 5, label: "label5" }
];
export default class App extends React.Component {
state = {
items: myList,
//This is the list of refs that will help you pick any item that ou want to focus
myButtonsRef: myList.map(i => React.createRef(i.label))
};
// Here you create a ref for each button
renderList = () => {
return this.state.items.map(i => (
<button key={i.id} ref={this.state.myButtonsRef[i.id]}>
{i.label}
</button>
));
};
//Here you pass the ref as an argument and just focus it
focusElement = item => {
item.current.focus();
};
render() {
return (
<div>
{this.renderList()}
<button
onClick={() => {
//Here you are able to focus any item that you want based on the ref in the state
this.focusElement(this.state.myButtonsRef[0]);
}}
>
Focus the item 0
</button>
</div>
);
}
}
Here is a sandbox if you want to play with the code

How to get Child component data in React

Here is my data flow from Parent component to Child
Parent component
import Add from './AddPage'; //addpage.jsx
......
let data =
[
{ id: 0, name: 'orange' },
{ id: 1, name: 'purple' },
{ id: 2, name: 'red' },
{ id: 3, name: 'blue' },
];
.......
<Add data= { data } />
Child component
How to get data in child component, i tried following method
const Child = ({ data }) => (
data.map((value => value.name))
);
when i use {Child}, it's shows
Uncaught ReferenceError: Chid is not defined
Edit
Use in my AddForm
let AddForm = props => {
const { handleSubmit } = this.props
return(
<div className="form-row">
<div className="col-md-12">
<form onSubmit={handleSubmit(onSubmit)}>
<Field
name="colors"
component={renderMultiselect}
data={Child}
valueField="id"
textField="name"
label="Colors"
/>
<button type="submit">Submit</button>
</form>{/* form end*/}
</div>{/* col-md-6f*/}
</div>/*main row*/
);
}
data using in Multiselect valueField

Using JsonSchemaForm on change to update field's content

I am trying to use JsonSchema-Form component but i ran into a problem while trying to create a form that, after choosing one of the options in the first dropdown a secondary dropdown should appear and give him the user a different set o options to choose depending on what he chose in the first dropdown trough an API call.
The thing is, after reading the documentation and some examples found here and here respectively i still don't know exactly how reference whatever i chose in the first option to affect the second dropdown. Here is an example of what i have right now:
Jsons information that are supposed to be shown in the first and second dropdowns trough api calls:
Groups: [
{id: 1,
name: Group1}
{id: 2,
name: Group2}
]
User: [User1.1,User1.2,User2.1,User2.2,User3.1,User3.2, ....]
If the user selects group one then i must use the following api call to get the user types, which gets me the the USER json.
Component That calls JSonChemaForm
render(){
return(
<JsonSchemaForm
schema={someSchema(GroupOptions)}
formData={this.state.formData}
onChange={{}}
uiSchema={someUiSchema()}
onError={() => {}}
showErrorList={false}
noHtml5Validate
liveValidate
>
)
}
SchemaFile content:
export const someSchema = GroupOptions => ({
type: 'object',
required: [
'groups', 'users',
],
properties: {
groups: {
title: 'Group',
enum: GroupOptions.map(i=> i.id),
enumNames: GroupOptions.map(n => n.name),
},
users: {
title: 'Type',
enum: [],
enumNames: [],
},
},
});
export const someUISchema = () => ({
groups: {
'ui:autofocus': true,
'ui:options': {
size: {
lg: 15,
},
},
},
types: {
'ui:options': {
size: {
lg: 15,
},
},
},
});
I am not really sure how to proceed with this and hwo to use the Onchange method to do what i want.
I find a solution for your problem.There is a similar demo that can solve it in react-jsonschema-form-layout.
1. define the LayoutField,this is part of the demo in react-jsonschema-form-layout.To make it easier for you,I post the code here.
Create the layoutField.js.:
import React from 'react'
import ObjectField from 'react-jsonschema-form/lib/components/fields/ObjectField'
import { retrieveSchema } from 'react-jsonschema-form/lib/utils'
import { Col } from 'react-bootstrap'
export default class GridField extends ObjectField {
state = { firstName: 'hasldf' }
render() {
const {
uiSchema,
errorSchema,
idSchema,
required,
disabled,
readonly,
onBlur,
formData
} = this.props
const { definitions, fields, formContext } = this.props.registry
const { SchemaField, TitleField, DescriptionField } = fields
const schema = retrieveSchema(this.props.schema, definitions)
const title = (schema.title === undefined) ? '' : schema.title
const layout = uiSchema['ui:layout']
return (
<fieldset>
{title ? <TitleField
id={`${idSchema.$id}__title`}
title={title}
required={required}
formContext={formContext}/> : null}
{schema.description ?
<DescriptionField
id={`${idSchema.$id}__description`}
description={schema.description}
formContext={formContext}/> : null}
{
layout.map((row, index) => {
return (
<div className="row" key={index}>
{
Object.keys(row).map((name, index) => {
const { doShow, ...rowProps } = row[name]
let style = {}
if (doShow && !doShow({ formData })) {
style = { display: 'none' }
}
if (schema.properties[name]) {
return (
<Col {...rowProps} key={index} style={style}>
<SchemaField
name={name}
required={this.isRequired(name)}
schema={schema.properties[name]}
uiSchema={uiSchema[name]}
errorSchema={errorSchema[name]}
idSchema={idSchema[name]}
formData={formData[name]}
onChange={this.onPropertyChange(name)}
onBlur={onBlur}
registry={this.props.registry}
disabled={disabled}
readonly={readonly}/>
</Col>
)
} else {
const { render, ...rowProps } = row[name]
let UIComponent = () => null
if (render) {
UIComponent = render
}
return (
<Col {...rowProps} key={index} style={style}>
<UIComponent
name={name}
formData={formData}
errorSchema={errorSchema}
uiSchema={uiSchema}
schema={schema}
registry={this.props.registry}
/>
</Col>
)
}
})
}
</div>
)
})
}</fieldset>
)
}
}
in the file, you can define doShow property to define whether to show another component.
Next.Define the isFilled function in JsonChemaForm
const isFilled = (fieldName) => ({ formData }) => (formData[fieldName] && formData[fieldName].length) ? true : false
Third,after you choose the first dropdown ,the second dropdown will show up
import LayoutField from './layoutField.js'
const fields={
layout: LayoutField
}
const uiSchema={
"ui:field": 'layout',
'ui:layout': [
{
groups: {
'ui:autofocus': true,
'ui:options': {
size: {
lg: 15,
},
},
}
},
{
users: {
'ui:options': {
size: {
lg: 15,
},
},
doShow: isFilled('groups')
}
}
]
}
...
render() {
return (
<div>
<Form
schema={schema}
uiSchema={uiSchema}
fields={fields}
/>
</div>
)
}

Custom component failed with map

I try to write to make my own custom component but it doesn't work as I wish. The interaction seems ok but the it's only render the last item of the arrays.
export default class MyComponent extends Component {
constructor() {
super()
this.state = {
openItems: false,
selectedItem: 'Please select'
}
}
render() {
const { items, className } = this.props
const { openItems, selectedItem } = this.state
return (
<div className={classnames('myComponent', className)}>
<div tabIndex="1"
onBlur={() => this.setState({ openItems: false })}
onFocus={() => this.setState({ openItems: true })}>
{selectedItem}
<div className={classnames({'show': openItems === true, 'hide': openItems === false})}>
{items.map((obj, i) => {
return(
<li onClick={() => this.setState({ selectedItem: obj.name, openItems: false })}
key={i}>
{obj.name}
</li>
)
})}
</div>
</div>
</div>
)
}
}
and somewhere I used the component like this
<MyComponent items={[{
name: 'abc',
name: 'def',
name: 123
}]} />
I have no clue what the mistake is.
Your component expects an array of object with the key name. When you've initialized your component, you've only passed in a single object with the key name duplicated three times:
<MyComponent items={[{
name: 'abc',
name: 'def', // <-- this overrides the previous 'abc'
name: 123 // <-- this overrides the previous 'def'
}]} />
What you want is this:
<MyComponent items={[
{ name: 'abc' },
{ name: 'def' },
{ name: 123 },
]} />
You seem to be passing the same object name thrice, this will override the previous values and the latest value will take the final form.
Consider passing different values with different names.
<MyComponent items={[{ name: 'abc',
name: 'def',
name: 123
}]} />
pass the props into the constructor method as I am looking you have not passed the props so let's try to add props into the constructor as given below:-
constructor(props) {
super(props)
this.state = {
openItems: false,
selectedItem: 'Please select'
}
}

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