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Build 881
Hands-on tutorial · Extensions

Consume a reusable visual control

Set public properties and handle an event from an installed control package.

1 Form / control designs1 complete BASIC filesGuided sample project

A package reference is a contract and a dependency, not a pasted copy of the control’s source. Resolve the declared package before Check. In the consumer, respond to OpenRequested and access only the public properties exposed by the control.

Step 1Prepare a safe practice project#

Extract the archive into a new writable folder, separate from your own application. Open CustomerCardConsumer.mcproj in McBasic™. Keep every declared source, layout, resource and migration file together.

To reconstruct it yourself, create a DesktopApp project and add the files declared below. In the complete project, follow these steps as a guided rebuild: replace each named source file once and Check after all its procedures are present.

Exact project configuration
CustomerCardConsumer.mcproj
{
  "schemaVersion": 1,
  "projectId": "d70b2ed0-0e63-4bb9-8f2a-0d7dcb7a2d2a",
  "name": "CustomerCardConsumer",
  "kind": "DesktopApp",
  "language": {
    "dialect": "McBasic1",
    "requireExplicit": true,
    "compare": "Binary",
    "defaultArrayBase": 0
  },
  "application": {
    "bundleIdentifier": "com.mcbasic.samples.customercardconsumer",
    "version": "0.1.0",
    "buildNumber": "1",
    "startupFormId": "form-main",
    "shutdownMode": "OnStartupFormClosed"
  },
  "packages": [
    {
      "id": "com.mcbasic.samples.customercard",
      "version": "1.0.0"
    }
  ],
  "forms": [
    {
      "id": "form-main",
      "typeName": "frmMain",
      "layout": "Forms/frmMain.form.json",
      "code": "Forms/frmMain.bas"
    }
  ],
  "modules": [],
  "classes": [],
  "tests": [],
  "references": [],
  "resources": [],
  "targets": [
    "osx-arm64"
  ],
  "capabilities": []
}

Step 2Build the Form and set its properties#

frmMain

Select the Form first and set its properties. Add containers before their children. These are initial Designer values, not statements to paste into a procedure.

Form propertyValue
Caption"CustomerCard package consumer"
Width520
Height260
MinWidth460
MinHeight220
TypeNameParent
CustomerCard (package)customerCard1Form
LabellblStatusForm
customerCard1 · exact Inspector values
PropertyValue
Left24
Top28
Width360
Height120
CustomerId"C-1843"
CustomerName"Ada Lovelace"
lblStatus · exact Inspector values
PropertyValue
Left24
Top172
Width450
Height36
Caption"The trusted package control is ready."

Step 3Connect the events explicitly#

frmMain

ObjectEventProcedureParameters
customerCard1OpenRequestedcustomerCard1_OpenRequestedOpenRequested()
FormShownForm_Shown()

Step 4Enter the complete behavior#

Open the named source file. Enter declarations first, then every procedure. Expand a procedure for its full body, or copy the complete file. Helpers are required: do not stop after entering the first Click handler.

Forms/frmMain.bas

Enter these declarations at file scope, before the procedures.

Forms/frmMain.bas · declarations
Option Explicit
Private Sub Form_Shown()

Initialize state before enabling dependent actions. Keep the shared declarations and startup dependencies with this procedure.

Forms/frmMain.bas · Form_Shown
Private Sub Form_Shown()
    customerCard1.CustomerId = "C-1843"
    customerCard1.CustomerName = "Ada Lovelace"
End Sub
Private Sub customerCard1_OpenRequested()

Enter this helper in the named source file, outside every other procedure. Its callers are included in the same project.

Forms/frmMain.bas · customerCard1_OpenRequested
Private Sub customerCard1_OpenRequested()
    lblStatus.Caption = "Open " & customerCard1.CustomerId & ": " & customerCard1.CustomerName
End Sub
Copy the complete Forms/frmMain.bas file

Replace the file once; do not append duplicate procedures.

Forms/frmMain.bas
Option Explicit

Private Sub Form_Shown()
    customerCard1.CustomerId = "C-1843"
    customerCard1.CustomerName = "Ada Lovelace"
End Sub

Private Sub customerCard1_OpenRequested()
    lblStatus.Caption = "Open " & customerCard1.CustomerId & ": " & customerCard1.CustomerName
End Sub

Step 5Keep resources and storage reproducible#

No external resource or migration files are declared. Any inline migration, seed data or local JSON is present in the code above. Runtime application data and private preferences are not included in the archive.

Step 6Check, run and test the result#

Save all files and run Check. Resolve diagnostics before Run. Supply the resolved package inputs described in the SDK guide. Developer CLI users can work from the extracted folder:

Use the complete consumer command sequence, including its package options.

Acceptance checklist

  • Build and admit the CustomerCard package using the SDK instructions.
  • Resolve the consumer’s package reference and run Check.
  • Run and verify the initial property values.
  • Activate the control’s command and inspect the consumer event.

Step 7Make one change and repeat the tests#

Use a second instance and confirm the two instances keep independent state.

Save a working Git checkpoint first. Change one behavior, Check again and repeat the acceptance checklist. Compare with the downloaded solution if a regression appears.

Source baseline 20f4bfed6b · Build manifest