(PowerBuilder) 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.

Note: This example requires Chilkat v11.5.0 or greater.

For more information, see https://www.chilkatsoft.com/curl_dependency_engine.asp

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
integer li_Success
oleobject loo_HttpCurl
string ls_TargetCurl
string ls_FnName
oleobject loo_PlanJson

li_Success = 0

loo_HttpCurl = create oleobject
li_rc = loo_HttpCurl.ConnectToNewObject("Chilkat.HttpCurl")
if li_rc < 0 then
    destroy loo_HttpCurl
    MessageBox("Error","Connecting to COM object failed")
    return
end if

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

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

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

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

// Examine the execution plan without running any requests.
loo_PlanJson = create oleobject
li_rc = loo_PlanJson.ConnectToNewObject("Chilkat.JsonObject")

loo_PlanJson.EmitCompact = 0

li_Success = loo_HttpCurl.ExaminePlan(ls_TargetCurl,loo_PlanJson)

// Success is expected to be 1.
Write-Debug "success = " + string(li_Success)

Write-Debug loo_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": []
//   }]
// }


destroy loo_HttpCurl
destroy loo_PlanJson