Callback functions

All router operations can accept functions as arguments.

Let’s say we have some mutation that will report its progress.

router.ts


import { createRouter, mutation } from "superbridge/main";
 
function wait(ms: number) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}
 
export const appRouter = createRouter({
  processFile: mutation(async (filePath: string, onProgress: (progress: number) => void) => {
    for (let i = 0; i < 10; i++) {
      const progress = i / 10;
      onProgress(progress);
      await wait(1000);
    }
 
    return {
      result: "success",
    };
  }),
});

Now, let’s call this mutation from the client.

example.ts


const result = await appClient.processFile("path/to/file", (progress) => {
  console.log(`Progress: ${progress * 100}%`);
});
 
console.log(result); // { result: "success" }

Note

Callback functions can return values (including another callback function).

However, the result is always returned as a promise, even if the callback itself is a synchronous function. Make sure to properly type your callback return value or always await the result.