C

curl with Variable Substitution in the Request Body

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This example demonstrates using variables located in the request body with the {{variable_name}} syntax. C

#include <C_CkStringBuilder.h>
#include <C_CkHttpCurl.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkStringBuilder sbCurl;
    HCkHttpCurl curl;
    HCkStringBuilder sbRawRequest;

    success = FALSE;

    //  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}}}'

    sbCurl = CkStringBuilder_Create();
    CkStringBuilder_AppendLn(sbCurl,"curl -X POST https://api.example.com/data \\");
    CkStringBuilder_AppendLn(sbCurl,"  -H \"Content-Type: application/json\" \\");
    CkStringBuilder_AppendLn(sbCurl,"  -d '{\"name\":\"{{name}}\",\"age\":{{age}}}'");

    curl = CkHttpCurl_Create();

    //  Provide values for variables.
    CkHttpCurl_SetVar(curl,"name","Alice");
    CkHttpCurl_SetVar(curl,"age","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.
    sbRawRequest = CkStringBuilder_Create();
    success = CkHttpCurl_ToRawRequest(curl,CkStringBuilder_getAsString(sbCurl),sbRawRequest);
    if (success == FALSE) {
        printf("%s\n",CkHttpCurl_lastErrorText(curl));
        CkStringBuilder_Dispose(sbCurl);
        CkHttpCurl_Dispose(curl);
        CkStringBuilder_Dispose(sbRawRequest);
        return;
    }

    printf("%s\n",CkStringBuilder_getAsString(sbRawRequest));

    //  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 FALSE

    CkHttpCurl_putEnableBodyVars(curl,FALSE);

    success = CkHttpCurl_ToRawRequest(curl,CkStringBuilder_getAsString(sbCurl),sbRawRequest);
    if (success == FALSE) {
        printf("%s\n",CkHttpCurl_lastErrorText(curl));
        CkStringBuilder_Dispose(sbCurl);
        CkHttpCurl_Dispose(curl);
        CkStringBuilder_Dispose(sbRawRequest);
        return;
    }

    printf("%s\n",CkStringBuilder_getAsString(sbRawRequest));

    //  The raw request with body variable substitution disable:

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


    CkStringBuilder_Dispose(sbCurl);
    CkHttpCurl_Dispose(curl);
    CkStringBuilder_Dispose(sbRawRequest);

    }