I'm a seasoned SFDC Dev, but fairly new to JS. I've read several documentations (Trailhead, Mozilla, ES6, W3) on JS since yesterday, trying to figure this out.
Why is this line...
this.mandatedActivities.push(activity);
...failing with... "Cannot read property 'mandatedActivities' of undefined"
import {LightningElement, wire} from 'lwc';
import getAllEventActivities from '@salesforce/apex/EventActivities_Ctrl.getAllEventActivities';
export default class EventActivityChecklist extends LightningElement {
activities = [];
mandatedActivities = [];
@wire(getAllEventActivities) getAllEventActivitiesHandler({ data, error }) {
if (data) {
this.activities = data;
if(this.activities) {
this.activities.forEach(function(activity) {
if(activity.Type__c == "Mandated Activity") {
//Failing here: Cannot read property 'mandatedActivities' of undefined
this.mandatedActivities.push(activity);
}
})
}
} else if (error) {
console.log(error);
}
}
}
New Code, based on SFDC Fox's answer
<template>
<lightning-card title="Activities" icon-name="custom:custom14">
<ul>
<template for:each={mandatedActivities} for:item="activity">
<span key={activity.id}>
<div class="slds-col">
<lightning-input type="checkbox" label={activity.Title__c} ></lightning-input>
</div>
</span>
</template>
</ul>
</lightning-card>
</template>
import {LightningElement, wire} from 'lwc';
import getAllEventActivities from '@salesforce/apex/EventActivities_Ctrl.getAllEventActivities';
export default class EventActivityChecklist extends LightningElement {
activities = [];
mandatedActivities = [];
@wire(getAllEventActivities) getAllEventActivitiesHandler({ data, error }) {
if (data) {
this.activities = data;
if(this.activities) {
this.activities.forEach((activity) => {
if(activity.Type__c == "Mandated Activity") {
this.mandatedActivities.push(activity);
}
})
console.log("mandatedActivities: ",this.mandatedActivities);
}
} else if (error) {
console.log(error);
}
}
}
Console log shows here I now have an array of mandatedActivities. In the HTML, instead of looping through activities, I changed it to mandatedActivities. The prior displayed activities just fine. The latter does not display mandatedActivities in the view.
