Delphi ActiveX Requires Chilkat v11.5.0+

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.

Delphi ActiveX

var
success: Integer;
httpCurl: TChilkatHttpCurl;
targetCurl: WideString;
fnName: WideString;
planJson: TChilkatJsonObject;

begin
success := 0;

httpCurl := TChilkatHttpCurl.Create(Self);

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

//  Define a helper function that produces order_id from customer_id.
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.
planJson := TChilkatJsonObject.Create(Self);
planJson.EmitCompact := 0;

success := httpCurl.ExaminePlan(targetCurl,planJson.ControlInterface);

//  Success is expected to be 1.
Memo1.Lines.Add('success = ' + IntToStr(Ord(success)));

Memo1.Lines.Add(planJson.Emit());

//  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": []
//    }]
//  }