getRelatedListCount

1import { LightningElement, wire } from 'lwc';
2import { getRelatedListCount } from 'lightning/uiRelatedListApi';
3
4export default class LdsGetRelatedListCount extends LightningElement {
5  @wire(getRelatedListCount, {
6      parentRecordId: '001RM000003UNu6YAG',
7      relatedListId: 'Contacts',
8  })
9}

1GET /ui-api/related-list-count/${parentRecordId}/${relatedListId}

1<!-- wireGetRelatedListCount.html -->
2<template>
3  <lightning-card title="wireGetRelatedListCount">
4    <template lwc:if={responseData}>
5      <div class="slds-m-around_medium">
6        <p key={responseData.count}>{responseData.count} : {responseData.hasMore}</p>
7      </div>
8    </template>
9  </lightning-card>
10</template>

1// wireGetRelatedListCount.js
2import { LightningElement, wire } from "lwc";
3import { getRelatedListCount } from "lightning/uiRelatedListApi";
4export default class WireGetRelatedListCount extends LightningElement {
5  error;
6  responseData;
7  @wire(getRelatedListCount, {
8    parentRecordId: "001RM000003UNu6YAG",
9    relatedListId: "Contacts",
10  })
11  listInfo({ error, data }) {
12    if (data) {
13      this.responseData = data;
14      this.error = undefined;
15    } else if (error) {
16      this.error = error;
17      this.responseData = undefined;
18    }
19  }
20}