ion-alert

An Alert is a dialog that presents users with information or collects information from the user using inputs. An alert appears on top of the app's content, and must be manually dismissed by the user before they can resume interaction with the app. It can also optionally have a header, subHeader and message.

Presenting​

Controller​

Inline​

When using Ionic with React or Vue, ion-alert can also be placed directly in the template through use of the isOpen property. Note that isOpen must be set to false manually when the alert is dismissed; it will not be updated automatically.

importReact,{ useState }from'react';
import{IonAlert,IonButton,IonContent}from'@ionic/react';

functionExample(){
const[showAlert, setShowAlert]=useState(false);

return(
<IonContent>
<IonButtononClick={()=>setShowAlert(true)}>Click Me</IonButton>
<IonAlert
isOpen={showAlert}
onDidDismiss={()=>setShowAlert(false)}
header="Alert"
subHeader="Important message"
message="This is an alert!"
buttons={['OK']}
/>
</IonContent>
);
}

<template>
<ion-content>
<ion-button@click="setOpen(true)">Show Alert</ion-button>
<ion-alert
:is-open="isOpenRef"
header="Alert"
sub-header="Important message"
message="This is an alert!"
:buttons="['OK']"
@didDismiss="setOpen(false)"
></ion-alert>
</ion-content>
</template>

<scriptlang="ts">
import{IonAlert,IonButton,IonContent}from'@ionic/vue';
import{ defineComponent, ref }from'vue';

exportdefaultdefineComponent({
components:{IonAlert,IonButton},
setup(){
const isOpenRef =ref(false);
constsetOpen=(state: boolean)=>(isOpenRef.value= state);

return{ isOpenRef, setOpen };
},
});
</script>

Buttons​

In the array of buttons, each button includes properties for its text, and optionally a handler. If a handler returns false then the alert will not automatically be dismissed when the button is clicked. All buttons will show up in the order they have been added to the buttons array from left to right. Note: The right most button (the last one in the array) is the main button.

Optionally, a role property can be added to a button, such as cancel. If a cancel role is on one of the buttons, then if the alert is dismissed by tapping the backdrop, then it will fire the handler from the button with a cancel role.

Inputs​

Alerts can also include several different inputs whose data can be passed back to the app. Inputs can be used as a simple way to prompt users for information. Radios, checkboxes and text inputs are all accepted, but they cannot be mixed. For example, an alert could have all radio button inputs, or all checkbox inputs, but the same alert cannot mix radio and checkbox inputs. Do note however, different types of "text" inputs can be mixed, such as url, email, text, textarea etc. If you require a complex form UI which doesn't fit within the guidelines of an alert then we recommend building the form within a modal instead.

Text Inputs Example​

Radio Example​

Customization​

Alert uses scoped encapsulation, which means it will automatically scope its CSS by appending each of the styles with an additional class at runtime. Overriding scoped selectors in CSS requires a higher specificity selector.

We recommend passing a custom class to cssClass in the create method and using that to add custom styles to the host and inner elements. This property can also accept multiple classes separated by spaces.

/* DOES NOT WORK - not specific enough */
.alert-wrapper{
background:#e5e5e5;
}

/* Works - pass "my-custom-class" in cssClass to increase specificity */
.my-custom-class.alert-wrapper{
background:#e5e5e5;
}

Any of the defined CSS Custom Properties can be used to style the Alert without needing to target individual elements:

.my-custom-class{
--background:#e5e5e5;
}

Accessibility​

Ionic automatically sets the Alert's role to either alertdialog if there are any inputs or buttons included, or alert if there are none.

If the header property is defined for the Alert, the aria-labelledby attribute will be automatically set to the header's ID. The subHeader element will be used as a fallback if header is not defined. Similarly, the aria-describedby attribute will be automatically set to the ID of the message element if that property is defined.

It is strongly recommended that your Alert have a message, as well as either a header or subHeader, in order to align with the ARIA spec. If you choose not to include a header or subHeader, an alternative is to provide a descriptive aria-label using the htmlAttributes property.

All ARIA attributes can be manually overwritten by defining custom values in the htmlAttributes property of the Alert.

Interfaces​

AlertButton​

interfaceAlertButton{
 text:string;
 role?:'cancel'|'destructive'|string;
 cssClass?:string|string[];
 handler?:(value:any)=>boolean|void|{[key:string]:any};
}

AlertInput​

interfaceAlertInput{
 type?: TextFieldTypes |'checkbox'|'radio'|'textarea';
 name?:string;
 placeholder?:string;
 value?:any;
/**
 * The label text to display next to the input, if the input type is `radio` or `checkbox`.
 */
 label?:string;
 checked?:boolean;
 disabled?:boolean;
 id?:string;
 handler?:(input: AlertInput)=>void;
 min?:string|number;
 max?:string|number;
 cssClass?:string|string[];
 attributes?:{[key:string]:any};
 tabindex?:number;
}

AlertOptions​

interfaceAlertOptions{
 header?:string;
 subHeader?:string;
 message?:string| IonicSafeString;
 cssClass?:string|string[];
 inputs?: AlertInput[];
 buttons?:(AlertButton |string)[];
 backdropDismiss?:boolean;
 translucent?:boolean;
 animated?:boolean;
 htmlAttributes?:{[key:string]:any};

 mode?: Mode;
 keyboardClose?:boolean;
 id?:string;

 enterAnimation?: AnimationBuilder;
 leaveAnimation?: AnimationBuilder;
}

Properties​

animated​

backdropDismiss​

buttons​

cssClass​

enterAnimation​

header​

htmlAttributes​

inputs​

keyboardClose​

leaveAnimation​

message​

mode​

subHeader​

translucent​

Events​

Methods​

dismiss​

onDidDismiss​

onWillDismiss​

present​

CSS Shadow Parts​

No CSS shadow parts available for this component.

CSS Custom Properties​

Slots​

No slots available for this component.