Advice on basic design

I need to make a little piece of software that will take some other app’s text output, process it and return some more text.

The app that will supply the text data to me will be running in the same pc but it’s not written by me.

Now this is my first experience of this kind for me and I am not sure what is the best/easiest approach. What do you think of this ?

Given ProviderApp is the existing app and MyApp is what I will construct:

1.ProviderApp creates invoice.json and writes to defined folder
2.ProviderApp launch’s MyApp.exe
3.ProviderApp sets a timer to check for return.json in defined folder
4.MyApp reads invoice.json process it, delete it and writes return.json into defined folder
5.ProviderApp gets return.json and does its thing.

Do you guys see any problem with this file in / out + timer idea?
Could ProviderApp open/read return.json before its completly written by MyApp and cause data corruption?

Is there any alternative (easier/safer/cheaper) way to achieve this ?

Thanks!

How large are your json files? How much can you control ProvidingApp? Can you make ProvidingApp talk to your app with sockets?

@Beatrix Willius json files should be very small. A couple of kb.

I have zero control over providingapp.

I could talk to the developer, but not sure how much will he be willing to do.

With this size of file there shouldn’t be any problems. The file approach is the easiest way.

Thanks !!!