PowerShell 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. PowerShell

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

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

$curl = New-Object 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.
$sbRawRequest = New-Object Chilkat.StringBuilder
$success = $curl.ToRawRequest($sbCurl.GetAsString(),$sbRawRequest)
if ($success -eq $false) {
    $($curl.LastErrorText)
    exit
}

$($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
#    }
#  }