C++

Viewing a Simple Three-Step Execution Plan

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This example demonstrates a straightforward, valid dependency chain that results in a three-step execution plan. The goal is not to execute the requests, but to inspect how the plan is constructed using ExaminePlan.

The target curl command requires {{order_id}}. A helper function is defined to produce order_id, but it depends on customer_id. Another helper function produces customer_id, which depends on account_name.

Because account_name is provided as a known input, the dependency chain can be fully resolved:

• customer_id is obtained from account_name
• order_id is obtained from customer_id
• The target curl command uses order_id

When ExaminePlan is called, it builds and returns a three-step execution plan showing the order in which each function would be executed.

C++

#include <CkHttpCurl.h>
#include <CkJsonObject.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkHttpCurl httpCurl;

    // The target curl command requires {{order_id}}.
    const char *targetCurl = "curl -X GET https://api.example.com/orders/{{order_id}}";

    // Define a helper function that produces order_id from customer_id.
    const char *fnName = "getOrderId";
    httpCurl.AddFunction(fnName,"curl -X GET https://api.example.com/order-id?customer={{customer_id}}");
    httpCurl.AddOutput(fnName,"order.id","order_id");

    // Define a helper function that produces customer_id from account_name.
    fnName = "getCustomerId";
    httpCurl.AddFunction(fnName,"curl -X GET https://api.example.com/customer-id?account={{account_name}}");
    httpCurl.AddOutput(fnName,"customer.id","customer_id");

    // Provide the starting known input.
    httpCurl.SetVar("account_name","acme");

    // Examine the execution plan without running any requests.
    CkJsonObject planJson;
    planJson.put_EmitCompact(false);

    success = httpCurl.ExaminePlan(targetCurl,planJson);

    // Success is expected to be true.
    std::cout << "success = " << success << "\r\n";

    std::cout << planJson.emit() << "\r\n";

    // Expected result:
    // 
    // {
    //   "plan": [{
    //     "function": "getCustomerId",
    //     "inputs": ["account_name"],
    //     "outputs": ["customer_id"]
    //   },{
    //     "function": "getOrderId",
    //     "inputs": ["customer_id"],
    //     "outputs": ["order_id"]
    //   },{
    //     "function": "targetCurl",
    //     "inputs": ["order_id"],
    //     "outputs": []
    //   }]
    // }
    }