Create a policy

Intro

A policy is a class that implements the UCPolicy interface.

libmodulor provides policies that are commonly used. But some apps need specific policies.

Example

As an example, you can define a policy to allow some use cases only to "Pro" users.

src/lib/ProUCPolicy.ts

@injectable()
export class ProUCPolicy<
    I extends UCInput | undefined = undefined,
    OPI0 extends UCOPIBase | undefined = undefined,
    OPI1 extends UCOPIBase | undefined = undefined,
> implements UCPolicy<I, OPI0, OPI1>
{
    constructor(
        @inject('UserDataStore') private userDataStore: UserDataStore,
    ) {}

    public async canBeExecutedPreAuth(): Promise<boolean> {
        return false;
    }

    public async exec({
        uc,
    }: UCPolicyInput<I, OPI0, OPI1>): Promise<UCPolicyOutput> {
        const out = defaultUCPolicyOutput();

        const user = await this.userDataStore.get(uc.auth.user.id);
        if (!user) {
            return out;
        }

        out.allowed = user.plan === 'Pro';

        return out;
    }
}

In this example, we get the information from a hypothetical UserDataStore but you are free to inject anything you need in here.

Create a policy

Intro

Example

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