QTP: Creating Object Descriptions “On The Fly”

photo credit: h.koppdelaney

This article is a follow-up to the Descriptive Programming Series and will discuss a simple way of creating Object Descriptions on the fly. There are several reasons for using this approach, such as overcoming the need to write extra code and having the ability to make the change in only a single place while performing maintenance. This article includes the concepts and working examples of how and when we can must use this approach.

There are instances where object descriptions are incremented in a numerical context. In other words, a part of the object description stays the same, but these descriptions increment starting at a number, generally 0.

To illustrate, consider the below HTML_IDs for 4 list boxes in a Web Application:

List Box 1 HTML ID -> lstBox0
List Box 1 HTML ID -> lstBox1
List Box 1 HTML ID -> lstBox2
List Box 1 HTML ID -> lstBox3

Notice how the descriptions above increment. lstBox is common in all 4 descriptions, but there is a numerical increment after each, starting at 0. When creating an object description in such a scenario, you may tend to do the following:

Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstBox0").Select "Item"
Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstBox1").Select "Item"
Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstBox2").Select "Item"
Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstBox3").Select "Item"

The above is a common usage, and completely acceptable. But in practice, we may have more than 4 Objects with such descriptions and creating the same line of code over and over again, and maintaining everything can be quite a task. In such situations, the concept in this article can be quite beneficial. For example, the above code snippet can be condensed into:

'use a variable to increment from 0 to 3
For x = 0 to 3
	Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstBox" & x).Select "Item"
Next

Now, if the HTML_ID of this object changes, we have to make the change only once as opposed to several times. For example, if the HTML_ID of the list box above was to change from lstBox to lstObject, we would simply update our code like this:

For x = 1 to 4
	'lstBox becomes lstObject
	Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstObject" & x).Select "Item"
Next

Instead of updating it 4 times:

Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstObject0").Select "Item"
Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstObject1").Select "Item"
Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstObject2").Select "Item"
Browser("SomeBrowser").Page("SomePage").WebList("html id:=lstObject3").Select "Item"

Numeric Increments

Let’s see a working example. Please open a new IE browser and navigate to the following Page: Demo 1. You can simply set values in all of the text boxes using the following snippet:

With Browser("name:=SimpleDemo1.*").Page("micclass:=Page")
	For x = 1 to 6
		.WebEdit("html id:=txtDemo" & x ).Set "Text Box " & x
	Next
End With

Alphabetic Increments

Now imagine a similar situation where numeric increments are replaced with alphabets. There are several ways of working with such scenarios, but what I generally do is create an array with all the alphabets and increment elements of that array to work with runtime objects:

Dim arrAlphabets: ReDim arrAlphabets(25)
 
arrAlphabets = Array("a", "b", "c", "d", "e", "f", "g", "h", _
		"i", "j", "k", "l", "m", "n", "o", "p", "q", "r", _
		"s", "t", "u", "v", "w", "x", "y", "z")

Now, we can use the array of alphabets using the exact same approach we used for numeric descriptions on Demo Page 2.

With Browser("name:=SimpleDemo2.*").Page("micclass:=Page")
    For x = 1 to 6
        .WebEdit("html id:=txtDemo_" & arrAlphabets(x-1)).Set "Text Box " & UCase(arrAlphabets(x-1))
    Next
End With

If you are starting off with Descriptive Programming and VBScript Arrays, and would like to learn how the above approach works, please ask your questions in the comments section and I will try my best to help you.

Complex Increments

The above 2 uses of this technique are quite basic, and chances are that in your environment, you may not see such simple instances. Let’s create another scenario then, with a little complex description. Please open a new browser, and navigate to Demo Page 3.

When you spy on the WebEdits on this page, you will see a long description for the ‘name’ property. The name property of the six WebEdits are:

txt_applicant[0]BuyProductBox_answerString_A
txt_applicant[1]BuyProductItem_answerString_B
txt_applicant[2]BuyProductBall_answerString_C
txt_applicant[3]BuyProductBat_answerString_D
txt_applicant[4]BuyProductSpoon_answerString_E
txt_applicant[5]BuyProductFork_answerString_F

How can the description for this object be created such that, we can get our work done through a single line of code, instead of creating 6 different statements to set a value in each text box? Notice the descriptions closely, not only are the applicant numbers incrementing in numerical and alphabetical context, but the product lines are changing as well (Box, Item, Ball etc).

The trick here is to use RegularExpressions/WildCards to make the description generic so it becomes available to all 6 WebEdits. There are several ways this generic description can be created, and if you solved this using a different description, please feel free to share it.

Below is one possible solution for our complex scenario:

Dim arrAlphabets: ReDim arrAlphabets(25)
Dim sName
 
arrAlphabets = Array("a", "b", "c", "d", "e", "f", "g", "h", _
		"i", "j", "k", "l", "m", "n", "o", "p", "q", "r", _
		"s", "t", "u", "v", "w", "x", "y", "z")
 
With Browser("name:=SimpleDemo3.*").Page("micclass:=Page")
    For x = 0 to 5
        sName = "txt_applicant\[" & x & "\].*_" & arrAlphabets(x)
        .WebEdit("name:=" & sName).Set "Text Box " & UCase(arrAlphabets(x))
    Next
End With

Summary

This article summarized how working with objects with similar descriptions can be achieved in a simple manner. This approach may not be feasible for all environments, and should only be used when possible. You’re most likely to see Approach#3 in this article used most often, and at times, it does get a little tricky to write descriptions to work with all objects having similar properties.

This article is the last in the Introductory DP series, and future articles will cover advanced concepts and techniques of working with real-life applications.

I hope you guys find this article useful. Thanks for reading :)

Tagged as: Descriptive Programming, DP, RunTime Descriptions