1. Open the Cargo.toml file that has been generated for you
2. Under [dependencies], if you didn't do so in the last recipe, add the following lines:

reqwest = "0.8.5"
serde = "1.0.30"
serde_derive = "1.0.30"

3. If you want, you can go to request's (https://crates.io/crates/reqwest), serde's (https://crates.io/crates/serde), and serde_derive's (https://crates.io/crates/serde_derive) crates.io pages to check for the newest versions and use those ones instead
4. In the folder src/bin, create a file called making_requests.rs
5. Add the following code and run it with cargo run --bin making_requests:

1   extern crate reqwest;
2   #[macro_use]
3   extern crate serde_derive;
4   
5   use std::fmt;
6   
7   #[derive(Serialize, Deserialize, Debug)]
8   // The JSON returned by the web service that hands posts out
9   // it written in camelCase, so we need to tell serde about that
10  #[serde(rename_all = "camelCase")]
11  struct Post {
12    user_id: u32,
13    id: u32,
14    title: String,
15    body: String,
16  }
17  
18  #[derive(Serialize, Deserialize, Debug)]
19  #[serde(rename_all = "camelCase")]
20  struct NewPost {
21    user_id: u32,
22    title: String,
23    body: String,
24  }
25  
26  #[derive(Serialize, Deserialize, Debug)]
27  #[serde(rename_all = "camelCase")]
28  // The following struct could be rewritten with a builder
29  struct UpdatedPost {
30    #[serde(skip_serializing_if = "Option::is_none")]
31    user_id: Option,
32    #[serde(skip_serializing_if = "Option::is_none")]
33    title: Option,
34    #[serde(skip_serializing_if = "Option::is_none")]
35    body: Option,
36  }
37  
38  struct PostCrud {
39    client: reqwest::Client,
40    endpoint: String,
41  }
42  
43  impl fmt::Display for Post {
44    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
45      write!(
46        f,
47        "User ID: {}
ID: {}
Title: {}
Body: {}
",
48        self.user_id, self.id, self.title, self.body
49      )
50    }
51  }

The following code shows the requests being implemented:

53  impl PostCrud {
54    fn new() -> Self {
55      PostCrud {
56        // Build an HTTP client. It's reusable!
57        client: reqwest::Client::new(),
58        // This is a link to a fake REST API service
59        endpoint: 
          "https://jsonplaceholder.typicode.com/posts".to_string(),
60      }
61    }
62  
63    fn create(&self, post: &NewPost) -> Result<Post, 
      reqwest::Error> {
64      let response = 
        self.client.post(&self.endpoint).json(post).send()?.json()?;
65      Ok(response)
66    }
67  
68    fn read(&self, id: u32) -> Result<Post, reqwest::Error> {
69      let url = format!("{}/{}", self.endpoint, id);
70      let response = self.client.get(&url).send()?.json()?;
71      Ok(response)
72    }
73  
74    fn update(&self, id: u32, post: &UpdatedPost) -> Result<Post, 
      reqwest::Error> {
75      let url = format!("{}/{}", self.endpoint, id);
76      let response = 
        self.client.patch(&url).json(post).send()?.json()?;
77      Ok(response)
78    }
79  
80    fn delete(&self, id: u32) -> Result<(), reqwest::Error> {
81      let url = format!("{}/{}", self.endpoint, id);
82      self.client.delete(&url).send()?;
83      Ok(())
84    }
85  }

The following code shows us using our CRUD client:

87  fn main() {
88    let post_crud = PostCrud::new();
89    let post = post_crud.read(1).expect("Failed to read post");
90    println!("Read a post:
{}", post);
91  
92    let new_post = NewPost {
93      user_id: 2,
94      title: "Hello World!".to_string(),
95      body: "This is a new post, sent to a fake JSON API 
        server.
".to_string(),
96    };
97    let post = post_crud.create(&new_post).expect("Failed to  
      create post");
98    println!("Created a post:
{}", post);
99  
100   let updated_post = UpdatedPost {
101     user_id: None,
102     title: Some("New title".to_string()),
103     body: None,
104   };
105   let post = post_crud
106     .update(4, &updated_post)
107     .expect("Failed to update post");
108   println!("Updated a post:
{}", post);
109 
110   post_crud.delete(51).expect("Failed to delete post");
111 }