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Adding a semantic-ui-react modal with a self state
This guide will explain step by step how to add the code needed to create a component which contains an accesible modal, and also, buttons to open and close it. Thus, all the following code will be added in the component which implements the modal. Furthermore, at the end, the step 8 shows the final code for the this component.
- Requirements for using semantic-ui-react modal
Add the dependencies to package.json...if they are not:
Code Block language xml theme DJango "semantic-ui-react":"^0.67.1", "focus-trap-react":"^2^3.0.01",
Import all the semantic-ui-modal components needed, the focus trap and react moduls in the new component:
Code Block language js theme DJango import React from 'react'; import { Button, Icon, Modal, Container, Segment, Menu,Label,Input,Divider} from 'semantic-ui-react'; import FocusTrap from 'focus-trap-react';
Create the modal class, extending from React.Component as usual:
Code Block language js theme DJango class AccesibleModal extends React.Component{ ... }Prepare the constructor with the initial state, which will control if the modal will be displaying or not, and also, if the focus will be trapped to the modal or not, from the begining. For example, in this example the modal will be opened after pressing a button which is located in the same component.
Code Block language js theme DJango class AccesibleModal extends React.Component{ constructor(props) { super(props); this.state = { openModal: false, activeTrap: false }; } }Create the methods to open and close the modal, in the modal component itself.. Also, the method needed to unmount the trap focus component.
The method which opens the modal should change the state of the modal component and also set the aria-hidden label of the application to true. In fact, the element #app is the div element which contains all the SlideWiki page. It is defined in the 'components/DefaultHTMLLayout.js' component, at line 26:
Code Block language xml theme DJango title DeafultHTMLLayout.js ... <body> <div id="app" aria-hidden = "false" dangerouslySetInnerHTML={{__html: this.props.markup}}></div> ....
Thus, the following method will be enough to open the modal:Code Block language js theme DJango handleOpen(){class AccesibleModal extends React.Component{ ... handleOpen(){ $('#app').attr('aria-hidden','true'); this.setState({ modalOpen:true, activeTrap:true }); } ... }
We can bind it at the constructor also:
Code Block language js theme DJango class AccesibleModal extends React.Component{ constructor(props) { super(props); this.state = { openModal: false, activeTrap: false }; this.handleOpen = this.handleOpen.bind(this); } ... }
The method which close the modal should change the state of the modal component and also set the aria-hidden label of the application to false.
Code Block language js theme DJango handleClose(){ $('#app').attr('aria-hidden','false'); this.setState({ modalOpen:false, activeTrap: false }); }The method which unmounts the focus trap component should also change the state of the component. If we don't use it, if the user exits pressing outside the modal, the state of the component could be inconsistent.
Code Block language js theme DJango unmountTrap(){ if(this.state.activeTrap){ this.setState({ activeTrap: false }); $('#app').attr('aria-hidden','false'); } }Final constructor method:
Code Block language js theme DJango constructor(props) { super(props); this.state = { openModal: false, activeItem: 'MyDecks', activeTrap: false }; this.handleOpen = this.handleOpen.bind(this); this.handleClose = this.handleClose.bind(this); this.unmountTrap = this.unmountTrap.bind(this); }
Add the modal to the render method of the component, adding all the aria-labels required
Code Block language js theme DJango <Modal trigger={ <Button as="button" type="button" aria-label="Open" data-tooltip="Open" aria-hidden={this.state.modalOpen} basic onClick={this.handleOpen} > Open Button </Button> } open={this.state.modalOpen} onClose={this.handleClose} size="large" role="dialog" id="exampleModal" aria-labelledby="exampleModalHeader" aria-describedby="exampleModalDescription" tabIndex="0"> </Modal>- Trigger: Defines the button which will open the modal.You can see different attributes needed for making it fully accessible:
- as="button", because if not use it, semantic-ui-react render it as a div, which is not focusable. This also exposes the role of the element.
- aria-label="Open", this is required if there is no text on the button.It should contain explanation in case of a icon button. of the action of the button but it does not need to say that it is a button.
- data-tooltip="Open", extra information displayed when you pass over the button
- aria-hidden={this.state.modalOpen}, hides the button for reader when modal is open
- onClick={this.handleOpen}, association to the previously handleOpen method (which is binded in the constructor)
- open={this.state.modalOpen}, it controls if the modal is displayed (true) or not (false). Notice that in this case there is a difference with respect semantic-ui. when the modal is not open, also is not rendered in the final DOM, so the components it has inside are not available.
- Trigger: Defines the button which will open the modal.You can see different attributes needed for making it fully accessible:
Add the focus-trap component. Modals from semantic-ui and semantic-ui-react do not trap the focus, so when users taps over the last element of the modal, the focus goes outside the modal. This make them not accessible. In order to avoid that, we should use the focus-trap-react component. If incorrectly placed this component destroys some of the final layout. After many tests, we found a good way to introduce it with less impact: adding it under <Modal>, and surrounding the rest of the elements of the modal:
Code Block language js theme DJango <Modal trigger={ <Button as="button" type="button" aria-label="Open Button" data-tooltip="Open Button" aria-hidden={this.state.modalOpen} basic onClick={this.handleOpen} > Open Button </Button> } open={this.state.modalOpen} onClose={this.handleClose} size="large" role="dialog" id="exampleModal" aria-labelledby="exampleModalHeader" aria-describedby="exampleModalDescription" tabIndex="0"> <FocusTrap id='focus-trap-exampleModal' className = "header" active={this.state.activeTrap} focusTrapOptions={{ onDeactivate: this.unmountTrap, clickOutsideDeactivates: true, initialFocus: '#firstElement', }}> {/*elements of the modal here*/} </FocusTrap> </Modal>- className="header": using header as extra class, the impact in the final layout is reduced
- active={this.state.activeTrap}, controls if the focus is trap or not
- aria-label="Open Button", it is required. Should contain the name of the button displayed, or its explanation in case of an icon button.
- focusTrapOptions.onDeactivate:this.unmountTrap, In this property we add the call to the method which ensures the trap component is unmount, even the user exits the modal pressing outside
- focusTrapOptions.clickOutsidesDeactivates:true, also, it is the default value..
- initialFocus:'#firsElement', the id of the element which will receive the focus. I notice that f you don't indicate it, the modal does not receive the focus well
Add Modal Elements. As mentioned above, we need to add a header for the modal and an explanation about it. Of course, all the content needed and, most probably , some action buttons. We can add them as semantic-ui-react documentation suggest us, but taking into account some tips.
Code Block language js theme DJango linenumbers true <Modal trigger={ <Button as="button" type="button" aria-label="Open" data-tooltip="Open Button" aria-hidden={this.state.modalOpen} basic onClick={this.handleOpen} > Open Button </Button> } open={this.state.modalOpen} onClose={this.handleClose} size="large" role="dialog" id="exampleModal" aria-labelledby="exampleModalHeader" aria-describedby="exampleModalDescription" tabIndex="0"> <FocusTrap id='focus-trap-exampleModal' className = "header" active={this.state.activeTrap} focusTrapOptions={{ onDeactivate: this.unmountTrap, clickOutsideDeactivates: true, initialFocus: '#firstElement', }}> {/*elements of the modal here*/} <Modal.Header className="ui center aligned" as="h1" id="exampleModalHeader"> Accesible Modal </Modal.Header> <Modal.Content> <Container> <Segment color="blue" textAlign="center" padded> <Segment attached='bottom' textAlign="left"> <TextArea className="sr-only" id="exampleModalDescription" value="This modal only is a an example of how make a modal fully accessible" /> <Label htmlFor="firstElement" as="label" basic color="blue" pointing="right">Input some text</Label> <Input type="text" id="firstElement" placeholder="You should input something.." tabIndex="0" /> </Segment>; </Segment> <Modal.Actions> <Button color="green" tabIndex="0" type="button" aria-label="Accept" data-tooltip="Accept"> Accept </Button> <Button color='red' tabIndex="0" type="button" aria-label="Cancel" data-tooltip="Cancel" onClick={this.handleClose} > Cancel </Button> </Modal.Actions> </Segment> </Container> </Modal.Content> </FocusTrap> </Modal>- <Modal.Header className="ui center aligned" as="h1" id="exampleModalHeader">:
- className="ui center aligned": it is the semantic ui class we used in our previous modals
- as="h1": in order it was finally rendered as h1, which is mandatory
- id="exampleModalHeader": the id used in aria-labelledby attribute in the modal (see line 12)
- <Modal.Content>, all the content of the modal should be defined here. It should have a Container inside, which also has at least two segments:
- <Segment color="blue" textAlign="center" padded>
- <Modal.Header className="ui center aligned" as="h1" id="exampleModalHeader">:
- : in order to use the same style than in previous modals
- <TextArea className="sr-only" id="exampleModalDescription"... />: This text is only viewed by screen readers, and it is added to explain the content of the modal. For this reason it has the id=exampleModalDescription, which was previously used in the aria-describedby attributte of the modal (see line 36 ). If the modal contains an explanation to all users, we can use this explanation as a target of the aria-describedby label.
- <Modal.Actions>:
they - they should be added nested to the firt segment element. The documentation indicates to add them at the same level than content, but when we use the FocusTrap, the final style of the buttons looks horrible. Thus, it is better using them inside the first segment element, because it has a better appareance.
- they should be added nested to the firt segment element. The documentation indicates to add them at the same level than content, but when we use the FocusTrap, the final style of the buttons looks horrible. Thus, it is better using them inside the first segment element, because it has a better appareance.
- <Button color='red' tabIndex="0" type="button" aria-label="Cancel" data-tooltip=
"Cancel" onClick={this.handleClose} >: This is the button for closing the modal. It has all the aria attributes required: type, aria-label and data-tooltip. Also, its onClick event is associated to the This.handleClose method previously declared. - "Cancel" onClick={this.handleClose} >: This is the button for closing the modal. It has all the aria attributes required: type, aria-label and data-tooltip. Also, its onClick event is associated to the This.handleClose method previously declared.
- Final code for the modal component:
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import React from 'react';
import { Button, Icon, Modal, Container, Segment, Menu,Label,Input,Divider} from 'semantic-ui-react';
import FocusTrap from 'focus-trap-react';
class AccesibleModal extends React.Component{
constructor(props) {
super(props);
this.state = {
openModal: false,
activeItem: 'MyDecks',
activeTrap: false
};
this.handleOpen = this.handleOpen.bind(this);
this.handleClose = this.handleClose.bind(this);
this.unmountTrap = this.unmountTrap.bind(this);
}
handleOpen(){
$('#app').attr('aria-hidden','true');
this.setState({
modalOpen:true,
activeTrap:true
});
}
handleClose(){
$('#app').attr('aria-hidden','false');
this.setState({
modalOpen:false,
activeTrap: false
});
}
unmountTrap(){
if(this.state.activeTrap){
this.setState({ activeTrap: false });
$('#app').attr('aria-hidden','false');
}
}
render(){
return(
<Modal trigger={
<Button as="button"
type="button" aria-label="Open" data-tooltip="Open Button" aria-hidden={this.state.modalOpen}
basic onClick={this.handleOpen} > Open Button
</Button>
}
open={this.state.modalOpen}
onClose={this.handleClose}
size="large"
role="dialog"
id="exampleModal"
aria-labelledby="exampleModalHeader"
aria-describedby="exampleModalDescription"
tabIndex="0">
<FocusTrap
id='focus-trap-exampleModal'
className = "header"
active={this.state.activeTrap}
focusTrapOptions={{
onDeactivate: this.unmountTrap,
clickOutsideDeactivates: true,
initialFocus: '#firstElement',
}}>
{/*elements of the modal here*/}
<Modal.Header className="ui center aligned" as="h1" id="exampleModalHeader">
Accesible Modal
</Modal.Header>
<Modal.Content>
<Container>
<Segment color="blue" textAlign="center" padded>
<Segment attached='bottom' textAlign="left">
<TextArea className="sr-only" id="exampleModalDescription" value="This modal only is a an example of how make a modal fully accessible" />
<Label htmlFor="firstElement" as="label" basic color="blue" pointing="right">Input some text</Label>
<Input type="text" id="firstElement" placeholder="You should input something.." tabIndex="0" />
</Segment>;
<Segment>
<Modal.Actions>
<Button color="green" tabIndex="0" type="button" aria-label="Accept" data-tooltip="Accept">
Accept
</Button>
<Button color='red' tabIndex="0" type="button" aria-label="Cancel" data-tooltip="Cancel" onClick={this.handleClose} >
Cancel
</Button>
</Modal.Actions>
</Segment>
</Container>
</Modal.Content>
</FocusTrap>
</Modal>
);
}
} |
What happens if the modal should be controlled from another component?
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