Xojo Plugin Requires Chilkat v11.5.0+

curl with Variable Substitution in a GraphQL Request Body

See more CURL Examples

This example shows how to use variables inside a graphql request body using the {{variable_name}} syntax. When the HTTP request’s Content-Type indicates graphql, Chilkat automatically applies proper escaping to each substituted value, ensuring the resulting graphql remains valid. Xojo Plugin

Dim success As Boolean
success = False

success = False

//  Variable names are enclosed between {{ and }}
//  Important: Variables should be placed inside the quotes.

//  curl -X POST https://api.example.com/graphql \
//    -H "Content-Type: application/graphql; charset=utf-8" \
//    -H "Accept: application/json" \
//    --data-binary "mutation {
//    createUser(
//      input: {
//        name: \"{{name}}\"
//        city: \"{{city}}\"
//        note: \"{{note}}\"
//        bio: \"{{bio}}\"
//      }
//    ) {
//      id
//      name
//    }
//  }"

//  Build the above curl command.
Dim sbCurl As New Chilkat.StringBuilder
success = sbCurl.AppendLn("curl -X POST https://api.example.com/graphql \")
success = sbCurl.AppendLn("  -H ""Content-Type: application/graphql; charset=utf-8"" \")
success = sbCurl.AppendLn("  -H ""Accept: application/json"" \")
success = sbCurl.AppendLn("  -d ""mutation {")
success = sbCurl.AppendLn("  createUser(")
success = sbCurl.AppendLn("    input: {")
success = sbCurl.AppendLn("      name: \""{{name}}\""")
success = sbCurl.AppendLn("      city: \""{{city}}\""")
success = sbCurl.AppendLn("      note: \""{{note}}\""")
success = sbCurl.AppendLn("      bio: \""{{bio}}\""")
success = sbCurl.AppendLn("    }")
success = sbCurl.AppendLn("  ) {")
success = sbCurl.AppendLn("    id")
success = sbCurl.AppendLn("    name")
success = sbCurl.AppendLn("  }")
success = sbCurl.AppendLn("}""")

Dim curl As New Chilkat.HttpCurl

//  Provide values for variables
curl.SetVar "name","José O'Connor"
curl.SetVar "city","München"
curl.SetVar "note","He said ""Hello, world!"" — and left…"
curl.SetVar "bio","Loves sushi, café visits, and π ≈ 3.14159"

//  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.
Dim sbRawRequest As New Chilkat.StringBuilder
success = curl.ToRawRequest(sbCurl.GetAsString(),sbRawRequest)
If (success = False) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

System.DebugLog(sbRawRequest.GetAsString())

//  The output is shown below.
//  Notice the quote chars around "Hello, world!" are properly escaped.

//  POST /graphql HTTP/1.1
//  Accept: application/json
//  Host: api.example.com
//  Content-Type: application/graphql; charset=utf-8
//  Content-Length: 250
//  
//  mutation {
//    createUser(
//      input: {
//        name: "José O'Connor"
//        city: "München"
//        note: "He said \"Hello, world!\" — and left…"
//        bio: "Loves sushi, café visits, and π ≈ 3.14159"
//      }
//    ) {
//      id
//      name
//    }
//  }