Building JSON dynamically

When a JSON API is designed with a poorly-thought-out schema and inconsistent objects, you might end up with giant structures where most members are an Option. If you find yourself only sending data to such a service, it might be a bit easier to dynamically build your JSON property by property.

How to do it...

1. Open the Cargo.toml file that was generated earlier for you

2. Under [dependencies], if you haven't done so already, add the following line:

serde_json = "1.0.8"

3. If you want, you can go to the serde_json crates.io web page (https://crates.io/crates/serde_json) to check for the newest version and use that one instead

4. In the bin folder, create a file called dynamic_json.rs

5. Add the following code and run it with cargo run --bin dynamic_json:

1    #[macro_use] 
2    extern crate serde_json;
3 
4    use std::io::{self, BufRead};
5    use std::collections::HashMap;
6 
7    fn main() {
8      // A HashMap is the same as a JSON without any schema
9      let mut key_value_map...