Handling Data Operations in LWC: @wire, Promise, or async/await?

When building Lightning Web Components (LWC), one of the most important and often misunderstood topics is how to deal with asynchronous data fetching. Salesforce gives us multiple tools — namely @wire, Promise.then(), and async/await. Each comes with its strengths and caveats. In this post, we’ll dissect when to use what and how to avoid common pitfalls.

Understanding the Tools

Why @wire Isn’t Awaitable

You might be tempted to write this:

const objectInfo = await getObjectInfo({ objectApiName: 'Product2' });

But this results in:

LWC1503: "getObjectInfo" is a wire adapter and can only be used via the @wire decorator.

Wire adapters are reactive data providers. They are not traditional asynchronous functions and do not return Promises. You must either use them with the @wire decorator or the rare imperative pattern (if supported).

What is Declarative Programming?

Declarative programming is about stating your intent — the “what”. You describe what data you want, and the Salesforce framework (in this case) handles the how — fetching, updating, re-running, etc.

How @wire is Declarative:

• You declare a wire:
  @wire(getObjectInfo, { objectApiName: 'Product2' }) objectInfo;
• This line says: “Hey Salesforce, I want the object metadata for Product2.” But we don’t control when or how often it runs — the framework does.
• If the objectApiName changes, LWC reactively re-fetches the data.
• No manual await, .then(), or error catch logic is needed up front.

It’s similar to how formulas in Excel update when referenced cells change. You define what you want once — the system keeps it fresh.

In Contrast: Imperative Code (async/await or .then())

Imperative means telling the system how to do something, step-by-step.

const data = await getObjectInfo({ objectApiName: 'Product2' }); // Imperative

You’re telling the system: “Call this method, wait for the result, then continue.”

This is great when you need:

• Fine-grained control
• Error handling
• Sequencing (e.g., wait for recordTypeId, then fetch picklist values)

Declarative = less code, more magic. But it needs data dependencies to be right.

What are these Data Dependencies?

A data dependency tells Salesforce when to re-execute a wire function.

Example:

@track recordTypeId;

@wire(getPicklistValues, {
    recordTypeId: '$recordTypeId',
    fieldApiName: Status
}) picklistValues;

Here, recordTypeId is a reactive variable(@track). The $recordTypeId syntax makes it a dependency. So when recordTypeId changes, Salesforce re-runs the wire function automatically.

? If the dependency isn’t set correctly, the wire won’t run when it should. That’s a common source of bugs, especially when one wire depends on the output of another.

Common Pitfall: Chaining Wires Inside Promises

Here’s what not to do:

Promise.all([
    getDataRecords(),
    getObjectInfo({ objectApiName: PRODUCT_OBJECT }) // ❌ Invalid
])

getObjectInfo must be wired. It won’t work in Promise.all().

The Right Way: Reactive Wiring

@track recordTypeId;

@wire(getObjectInfo, { objectApiName: PRODUCT_OBJECT })
handleObjectInfo({ data, error }) {
    if (data) {
        this.recordTypeId = data.defaultRecordTypeId;
    } else {
        console.error('Error fetching object info', error);
    }
}

@wire(getPicklistValues, {
    recordTypeId: '$recordTypeId',
    fieldApiName: Status__c
})
handlePicklist({ data, error }) {
    if (data) {
        this.statusOptions = data.values;
    } else {
        console.error('Picklist fetch error', error);
    }
}

Notice the $recordTypeId. This creates a dependency so that getPicklistValues only fires when the recordTypeId becomes available.

When to Use async/await

When you’re calling custom Apex methods or performing logic that needs controlled sequencing:

async connectedCallback() {
    try {
        const [data, userBU] = await Promise.all([
            getDataRecords(),
            getCurrentUserBU()
        ]);
        this.processData(data, userBU);
    } catch (err) {
        console.error('Error loading metadata:', err);
    }
}

processData(data, userBU) {..processing}

This makes error handling cleaner and the logic easier to follow.

Smart Combo: Wire + Imperative

Use @wire for the reactive value, and trigger imperative logic based on that:

@wire(getObjectInfo, { objectApiName: PRODUCT_OBJECT })
handleObjectInfo({ data }) {
    if (data) {
        this.recordTypeId = data.defaultRecordTypeId;
        this.loadPicklist();
    }
}

loadPicklist() {
    getPicklistValues({
        recordTypeId: this.recordTypeId,
        fieldApiName: Status
    })
    .then(result => {
        this.statusOptions = result.values;
    })
    .catch(err => {
        console.error('Picklist fetch error:', err);
    });
}

Summary: When to Use What

Final Thoughts

In LWC, picking the right async strategy is more than just code style. It can mean the difference between a broken combobox and a smooth UX. Stick to @wire when you want reactive behavior. Use async/await for precision and control. Combine them smartly for real-world apps.

Have any questions or want a deep dive into picklist edge cases? Let us know in the comments.

Stay curious, stay declarative! ⚡