Building Custom LWCs

Keelstone includes a managed LWC bundle — kstone/api — that gives your components direct access to Office operations. Extend one of its classes, call a method, and the result comes back as a normal JavaScript await.

Install

The kstone/api bundle ships with the Keelstone managed package. No additional installation required.

Import

import { KSExcel } from 'kstone/api';

To use multiple product classes in the same file:

import { KSExcel, KSWord, KSPDF, KSCharts } from 'kstone/api';

Class hierarchy

LightningElement (platform)
    └── DocumentAPI  (internal — not exported)
            ├── KSExcel       — Excel operations (requires Excel add-in)
            ├── KSWord        — Word operations (requires Word add-in, Pro plan)
            ├── KSPowerPoint  — PowerPoint operations (requires PowerPoint add-in, Pro plan)
            ├── KSPDF         — PDF generation (server-side, no add-in required)
            ├── KSCharts      — Chart image generation (server-side, no add-in required)
            └── KSSalesforce  — Bulk API, Tooling API, and sObject describe (server-side)

DocumentAPI handles authentication and the server connection. You never interact with it directly — extend whichever product class matches your use case.

Class	Add-in required	Plan
KSExcel	Excel	All plans
KSWord	Word	Pro
KSPowerPoint	PowerPoint	Pro
KSPDF	None (server-side)	All plans
KSCharts	None (server-side)	All plans
KSSalesforce	None (server-side)	All plans

Minimal example

import { KSExcel } from 'kstone/api';
import { api }     from 'lwc';

export default class MyReport extends KSExcel {
    @api keelstoneSessionId;  // required — see Flow Wiring

    async connectedCallback() {
        const records = await this.getMyData();
        await this.ksWriteTable(
            ['Name', 'Revenue', 'Region'],
            records,
            'Sheet1!A1'
        );
    }
}

Re-declaring @api keelstoneSessionId

Salesforce flow screen wiring only populates @api properties declared on the component class itself — not inherited ones. Every component that extends a Keelstone class must re-declare this property:

export default class MyComponent extends KSExcel {
    @api keelstoneSessionId;  // must be on this class, not just in KSExcel
}

Without this, the flow cannot inject the session and every ks* call will throw at runtime.

Error handling

All ks* methods throw on failure. Wrap them in try/catch and display errors with a toast:

import { ShowToastEvent } from 'lightning/platformShowToastEvent';

async handleRun() {
    try {
        await this.ksQuery('SELECT Id, Name FROM Account LIMIT 100');
    } catch (err) {
        this.dispatchEvent(new ShowToastEvent({
            title: 'Error',
            message: err.message,
            variant: 'error',
        }));
    }
}

Next steps

• Walkthrough: Building a Salesforce Data Editor — end-to-end example using ksQuery, ksSaveTables, and ksSaveRecords
• KSExcel method reference
• KSWord method reference
• Flow Wiring — wire KeelstoneSessionId to your component
• PowerPoint generation — generate full presentations from Apex or LWC