Waiting for Object State Changes

Check object properties in a loop

Use the WaitProperty method

A loop can test conditions until they become true. In a keyword test, you implement a loop with the While Loop operation or the For Loop operation. In script tests, you use the for or while statements.

For example, to make a keyword test wait until a tested object is visible on screen:

1. Add a loop operation, for example, the While Loop operation, to your keyword test.

2. Specify the condition that will check that the object’s property has the expected value:

   • In the Value 1 column, click the ellipsis button.

   • In the resulting Edit Value dialog, set the mode to Object Property, and in the Value text box, specify the object property to check. You can type the property manually, or you can click the ellipsis button, select the object onscreen, and then select its property. The object must exist in the system.

     In our example, we select the VisibleOnScreen property.

   • In the Condition column, specify the condition that will validate the specified object’s property. In our example, we select Does not equal.

   • In the Value 2 column, click the ellipsis button and set the baseline value against which you want to validate the object’s property. In our case, we set the baseline value to False, so that our loop will go until the object’s VisibleOnScreen property turns True.

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Web (Cross-platform)

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Web (Cross-Platform)

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The script example below shows how to make a test to wait for an object to become visible on screen:

btn = Sys.Process("MyApp").Window("TMainFrm","MyApplication *").Child(2)
while not btn.VisibleOnScreen:
  pass

Browsers.Item[btChrome].Run("https://services.smartbear.com/samples/TestComplete14/smartstore/")
txtWelcome = Sys.Browser().Page("*").FindElement("//h1[.='Welcome to our store']")
while (txtWelcome.VisibleOnScreen != True):
  pass

Note, however, that using loops this way can slow down both the test’s performance and the performance of the application under test as the test engine will be constantly getting the object, retrieving its properties, and checking the condition. If you use the loop, make sure to add a delay command into it:

• In keyword tests, use the Delay operation:

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  Web (Cross-platform)

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  Click the image to enlarge it.

  Web (Cross-Platform)

  

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• In scripts, use the Delay method:

  Desktop

  Web (Cross-platform)

  Desktop

  JavaScript, JScript

  Python

  VBScript

  DelphiScript

  C++Script, C#Script

  Copy Code

  JavaScript, JScript

  btn = Sys.Process("MyApp").Window("TMainFrm","MyApplication*").Child(2);
  while(! btn.Enabled)
    Delay(1000); // 1 sec delay

  Python

  btn = Sys.Process("MyApp").Window("TMainFrm","MyApplication *").Child(2)
  while not btn.Enabled:
    Delay(1000) # 1 sec delay

  VBScript

  Set btn = Sys.Process("MyApp").Window("TMainFrm","MyApplication*").Child(2)
  While Not btn.Enabled
    Delay 1000 ' 1 sec delay
  WEnd

  DelphiScript

  btn := Sys.Process('MyApp').Window('TMainFrm','MyApplication *').Child(2);
  while not btn.Enabled do
    Delay(1000); // 1 sec delay

  C++Script, C#Script

  btn = Sys["Process"]("MyApp")["Window"]("TMainFrm","MyApplication *")["Child"](2);
  while(! Btn["Enabled"])
    Delay(1000); // 1 sec delay

  Web (Cross-Platform)

  JavaScript, JScript

  Python

  VBScript

  DelphiScript

  C++Script, C#Script

  Copy Code

  JavaScript, JScript

  Browsers.Item(btChrome).Run("https://services.smartbear.com/samples/TestComplete14/smartstore/");
  var txtWelcome = Sys.Browser().Page("*").FindElement("//h1[.='Welcome to our store']");
  while (txtWelcome.VisibleOnScreen != true)
    Delay(1000); // 1 sec delay

  Python

  Browsers.Item[btChrome].Run("https://services.smartbear.com/samples/TestComplete14/smartstore/")
  txtWelcome = Sys.Browser().Page("*").FindElement("//h1[.='Welcome to our store']")
  while (txtWelcome.VisibleOnScreen != True):
    Delay(1000) # 1 sec delay

  VBScript

  Browsers.Item(btChrome).Run("https://services.smartbear.com/samples/TestComplete14/smartstore/")
  Set txtWelcome = Sys.Browser().Page("*").FindElement("//h1[.='Welcome to our store']")
  While (txtWelcome.VisibleOnScreen <> True)
    Delay(1000) ' 1 sec delay
  WEnd

  DelphiScript

  var txtWelcome;
  …
  begin
  Browsers.Item(btChrome).Run('https://services.smartbear.com/samples/TestComplete14/smartstore/');
  txtWelcome := Sys.Browser().Page('*').FindElement('//h1[.="Welcome to our store"]');
  while txtWelcome.VisibleOnScreen <> true do
    Delay(1000); // 1 sec delay
  …
  end;

  C++Script, C#Script

  Browsers.Item(btChrome).Run("https://services.smartbear.com/samples/TestComplete14/smartstore/");
  var txtWelcome = Sys["Browser"]()["Page"]("*")["FindElement"]("//h1[.='Welcome to our store']");
  while (txtWelcome["VisibleOnScreen"] != true)
    Delay(1000); // 1 sec delay

To check whether a specific screen region is changed, use the Regions.Compare method. It compares two images and returns True if they are equal (see About Region Checkpoints).

The following example delays test execution until a specified screen region changes:

w = Sys.Desktop.ActiveWindow.Picture(20, 20, 50, 50)
while w.Compare(Sys.Desktop.ActiveWindow.Picture(20, 20, 50, 50)):
   aqUtils.Delay(500) # 0.5 sec delay

Another way to wait for a tested object to change its state is to use the WaitProperty method. It pauses the test run until the specified property equals the expected value or until the specified timeout expires. To check if the property gets the expected value, check if the WaitProperty method result is True.

Browsers.Item[btChrome].Run("https://services.smartbear.com/samples/TestComplete14/smartstore/")
txtWelcome = Sys.Browser().Page("*").FindElement("//h1[.='Welcome to our store']")
if (txtWelcome.WaitProperty("VisibleOnScreen", True, 2000)):
  # Element is visible
  pass
  # ...
else:
  # Element is not visible
  pass
  # ...

To call the method in keyword tests, use the Call Object Method operation:

1. Add the Call Object Method operation to your keyword test.

2. Specify the object whose state you want to check. You can type the object name manually or you can select the object onscreen.

3. Select the WaitProperty method of the object and specify the property to check, the expected value, and a timeout.

4. To check the WaitProperty method result, you can use the If…Then operation. Add the operation to your test right after the Call Object Method operation.

5. Configure the operation to compare the Last operation result to a boolean value.

Desktop

Web (Cross-platform)

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Click the image to enlarge it.

Web (Cross-Platform)

Click the image to enlarge it.

The benefit of the WaitProperty method is that it is more compact than the loop statement and it lets you easily limit the ”waiting“ time. However, the loop approach lets you detect changes in several object properties, while WaitProperty works for one property only.