(Objective-C) curl with Variable Substitution in the Request Body

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Note: This example requires Chilkat v11.5.0 or greater.

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#import <CkoStringBuilder.h>
#import <CkoHttpCurl.h>

BOOL success = NO;

// Variables can also be used within the HTTP request body.
// Variable names are enclosed between {{ and }}

// Here is a curl command with two variables {{name}} and {{age}} located in the data.

// curl -X POST https://api.example.com/data \
//   -H "Content-Type: application/json" \
//   -d '{"name":"{{name}}","age":{{age}}}'

CkoStringBuilder *sbCurl = [[CkoStringBuilder alloc] init];
[sbCurl AppendLn: @"curl -X POST https://api.example.com/data \\"];
[sbCurl AppendLn: @"  -H \"Content-Type: application/json\" \\"];
[sbCurl AppendLn: @"  -d '{\"name\":\"{{name}}\",\"age\":{{age}}}'"];

CkoHttpCurl *curl = [[CkoHttpCurl alloc] init];

// Provide values for variables.
[curl SetVar: @"name" varValue: @"Alice"];
[curl SetVar: @"age" varValue: @"30"];

// To demonstrate how the variables are replaced, this example does not execute the curl command. 
// Instead, it generates the raw HTTP request that would be sent if the curl command were run.
CkoStringBuilder *sbRawRequest = [[CkoStringBuilder alloc] init];
success = [curl ToRawRequest: [sbCurl GetAsString] sb: sbRawRequest];
if (success == NO) {
    NSLog(@"%@",curl.LastErrorText);
    return;
}

NSLog(@"%@",[sbRawRequest GetAsString]);

// Output:

// POST /data HTTP/1.1
// Host: api.example.com
// Content-Type: application/json
// Content-Length: 25
// 
// {"name":"Alice","age":30}

// --------------------------------------------------------------------------------------------------
// Note: Variable substitution in the request body can be turned off by 
// setting the EnableBodyVars property equal to NO

curl.EnableBodyVars = NO;

success = [curl ToRawRequest: [sbCurl GetAsString] sb: sbRawRequest];
if (success == NO) {
    NSLog(@"%@",curl.LastErrorText);
    return;
}

NSLog(@"%@",[sbRawRequest GetAsString]);

// The raw request with body variable substitution disable:

// Host: api.example.com
// Content-Type: application/json
// Content-Length: 33
// 
// {"name":"{{name}}","age":{{age}}}