How to Dynamically Access Params in Hono + Zod-OpenAPI Route Validation

[pincman]

I am using Hono + Zod OpenAPI to build an API, and I would like to use function validation on request.body within the createRoute function. I found that I cannot access params during the body validation; I can only configure a static Zod validation schema, and cannot dynamically generate it like manual validation. Is there any solution for this? The code is as follows:

.openapi(
        createRoute({
            tags: postTags,
            method: 'patch',
            summary: 'Update article',
            path: '/:id',
            request: {
                params: postDetailByIdRequestParamsSchema,
                body: async (value, c) => {
                    const params = c.req.param();
                    const schema = getPostItemRequestSchema(
                        await isSlugUniqueForFrontend(params.id),
                    );
                    const parsed = await schema.safeParseAsync(value);
                    if (!parsed.success) {
                        return c.json(createErrorResult('validate error'), 400);
                    }
                    return parsed.data;
                },
            },
            responses: {
                200: {
                    description: 'Updated article data',
                    content: {
                        'application/json': { schema: postItemResponseSchema.or(z.null()) },
                    },
                },
                400: {
                    description: 'validate error',
                    content: { 'application/json': { schema: errorSchema } },
                },
                500: {
                    description: '',
                    content: { 'application/json': { schema: errorSchema } },
                },
            },
        }),
        async (c) => {
            try {
                const params = c.req.valid('param');
                const body = c.req.valid('json');
                const result = await updatePostItem(params.id, body);
                return c.json(result, 200);
            } catch (error) {
                return c.json(createErrorResult('', error), 500);
            }
        },
    )