As a developer，I want to use the interface to search this information: which can get the validator detail information like the count of nominators and the commission and others information,
Everything that can be read onchain is listed here.
For example, to read the commission:
Which is a
Perbill, fixed point parts per billion, and
11uMPbeaEDJhUxzU4ZfWW9VQEsryP9XqFcNRfPdYda6aFWJ is a totally arbitrary validator of Polkadot today.
You can directly paste this into https://polkadot.js.org/apps/#/js.
To get the count of active nominator who end up backing a validator in era:
const lastEra = (await api.query.staking.currentEra()).unwrap(); const exposures = await api.query.staking.erasStakers(lastEra, "11uMPbeaEDJhUxzU4ZfWW9VQEsryP9XqFcNRfPdYda6aFWJ"); console.log(exposures.others.length)
To get the list of all the nominators who casted a vote for
11uMPbeaEDJhUxzU4ZfWW9VQEsryP9XqFcNRfPdYda6aFWJ, you have to iterate the
nominators map, but I will leave that up to you to figure out.