What if my wife and children is not in the U.S.?

Hello, I am new here and do not know a lot about the immigration law. I want to file an I-140 in the next year. I was told that you can include your wife and children in your I-140 petition so they will all be able to get a green card. But what if my family is not in the U.S.? Currently they live in China and my children go to school in China. They do have plans to relocate to U.S. in the near future. But will they be able to get the green cards if they are not here when I file the I-140?

to Phillip:

I asked my lawyer the same question and they said my wife and children can still get a green card by immigrant visa processing. I just need to file my I-140 and their process will begin after my I-140 approval.

to Megan:

Thank you!!
Who's your lawyer?

to Megan:

If so, will they be able to visit me on tourist visa during the application? I know that tourist visas are non-immigrant, so I'm a bit concerned that they'll get into trouble while traveling. Can some one reply?

to eugene.henderson498:

If they're going to do immigrant visa processing, they can travel however many times they want. It only becomes an issue if they're going to come to the US to file I-485 with you.