目录

Overview

Summary

Use Cases for Interacting with Salesforce Data

Handling Server Errors

Sample Code

Reference

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Overview

Summary

Use Cases for Interacting with Salesforce Data

Handling Server Errors

Sample Code

Prerequisite: 

1. Copy the ldsUtils folder from LWC recipes and include it in the force-app/main/default/lwc directory in your project. This component contains the reduceErrors function.

2. Import the reduceErrors function in your lwc js file.

1. Wire Property

import { LightningElement, api, wire } from "lwc";
// import reduceErrors method
import { reduceErrors } from "c/ldsUtils";
import getContactsBornAfter from "@salesforce/apex/ContactController.getContactsBornAfter";
export default class WireApexProperty extends LightningElement {
  @api minBirthDate;
  @wire(getContactsBornAfter, { birthDate: "$minBirthDate" })
  contacts;
  // handle server error with wire property
  get errors() {
    return (this.contacts.error) ?
      reduceErrors(this.contacts.error) : [];
  }
}

2. Wire Function

import { LightningElement, api, wire } from "lwc";
// import reduceErrors method
import { reduceErrors } from "c/ldsUtils";
import getContactsBornAfter from "@salesforce/apex/AccountController.getContactsBornAfter";
export default class WireApexFunction extends LightningElement {
  @api minBirthDate;
  errors;
  @wire(getContactsBornAfter, { birthDate: "$minBirthDate" })
  wiredContacts({ data, error }) {
    // handle server error with wire function
    if (error) this.errors = reduceErrors(error);
  }
}

3. Call LDS Function / Apex Imperatively

import { LightningElement, api, wire } from "lwc";
import { reduceErrors } from "c/ldsUtils";
import getContactsBornAfter from "@salesforce/apex/AccountController.getContactsBornAfter";
export default class CallApexImperative extends LightningElement {
  @api minBirthDate;
  errors;
  handleButtonClick() {
    getContactsBornAfter({
      birthDate: this.minBirthDate,
    })
      .then((contacts) => {
        // code to execute if the promise is resolved
      })
      .catch((error) => {
        this.errors = reduceErrors(error); // code to execute if the promise is rejected
      });
  }
}

Note:

1. Display error in pannel. Of course, you can also display via toast message.

<template>
    <lightning-card>
        <template if:true={contacts.data}>
            <lightning-datatable
                key-field="Id"
                data={contacts.data}
                columns={columns}
            >
           </lightning-datatable>
        </template>
        <template if:true={errors}>
            <p>{errors}</p>
        </template>
    </lightning-card>
</template>

2. To force error, include following code in you apex controller.

throw new AuraHandledException('Forced error');

Reference

Handle Server Errors Unit | Salesforce Trailhead