ExtractionRule Class
Base class used to define rules for obtaining data from a Web response that is generated by a Web test.
Namespace: Microsoft.VisualStudio.TestTools.WebTesting
Assembly: Microsoft.VisualStudio.QualityTools.WebTestFramework (in Microsoft.VisualStudio.QualityTools.WebTestFramework.dll)
Syntax
'Declaration
Public MustInherit Class ExtractionRule
'Usage
Dim instance As ExtractionRule
public abstract class ExtractionRule
public ref class ExtractionRule abstract
public abstract class ExtractionRule
Remarks
The ExtractionRule class must be inherited by any extraction rule whether it is user-written or built-in. Extraction rules that are associated with the request definition are run after a response has been received, and the results of the extraction are added to the WebTestContext.
Notes to Inheritors:
When you inherit from ExtractionRule, you must override the following members: Extract, RuleDescription, and RuleName.
Examples
The following custom extraction rule extracts checkboxes from the HtmlDocument and places the status of the found checkboxes into the context.
using System;
using Microsoft.VisualStudio.TestTools.WebTesting;
namespace ClassLibrary2
{
public class ExtractCheckBoxes : ExtractionRule
{
private string myContextParameter = "ExtractCBoxParam";
private bool isChecked = true;
public override string ContextParameterName
{
get { return myContextParameter; }
set
{
if (value != string.Empty)
myContextParameter = value;
}
}
public bool FindCheckedBoxes
{
get { return isChecked; }
set { isChecked = value; }
}
public override string RuleName
{
get { return "Extract Check Boxes"; }
}
public override string RuleDescription
{
get { return "Extract check boxes based on whether they are" +
" checked or not."; }
}
public override void Extract(object sender, ExtractionEventArgs e)
{
e.Success = false;
if (e.Response.HtmlDocument != null)
{ // Gets all input tags
foreach (HtmlTag tag in e.Response.HtmlDocument
.GetFilteredHtmlTags(new string[] { "input" }))
{ // Verify that current tag is a checkbox
if (tag.GetAttributeValueAsString("type") == "checkbox")
{ // Is the checkbox checked
if (tag.GetAttributeValueAsString("checked") == "CHECKED")
{ // Add checked checkboxes to context
if (isChecked)
{
e.WebTest.Context.Add(myContextParameter + "_" +
tag.GetAttributeValueAsString("id"),
"Is Checked");
e.Success = true;
}
}
else // The checkbox is not checked
{ // Add non-checked boxes to context
if (!isChecked)
{
e.WebTest.Context.Add(myContextParameter + "_" +
tag.GetAttributeValueAsString("id"),
"Is Not Checked");
e.Success = true;
}
}
}
}
}
if (e.Success)
e.Message = "Extracted checkboxes.";
else
e.Message = "No checkboxes extracted.";
}
}
}
Imports System
Imports Microsoft.VisualStudio.TestTools.WebTesting
Namespace ClassLibrary2
Public Class ExtractCheckBoxes
Inherits ExtractionRule
Private myContextParameter As String = "ExtractCBoxParam"
Private isChecked As Boolean = True
Public Overrides Property ContextParameterName() As String
Get
Return myContextParameter
End Get
Set(ByVal value As String)
If (value <> String.Empty) Then
myContextParameter = value
End If
End Set
End Property
Public Property FindCheckedBoxes() As Boolean
Get
Return isChecked
End Get
Set(ByVal value As Boolean)
isChecked = value
End Set
End Property
Public Overrides ReadOnly Property RuleName() As String
Get
Return "Extract Check Boxes"
End Get
End Property
Public Overrides ReadOnly Property RuleDescription() As String
Get
Return "Extract check boxes based on whether they are" + _
" checked or not."
End Get
End Property
Public Overrides Sub Extract(ByVal sender As Object, ByVal e As ExtractionEventArgs)
e.Success = False
If Not e.Response.HtmlDocument Is Nothing Then
' Gets all input tags
Dim tag As HtmlTag
For Each tag In e.Response.HtmlDocument.GetFilteredHtmlTags(New String() {"input"})
' Verify if current tag is a checkbox
If tag.GetAttributeValueAsString("type") = "checkbox" Then
' Is the check box checked
If tag.GetAttributeValueAsString("checked") = "CHECKED" Then
' Add checked checkbox to context
If isChecked = True Then
e.WebTest.Context.Add(myContextParameter + "_" + _
tag.GetAttributeValueAsString("id"), "Is Checked")
e.Success = True
End If
Else ' The check box is not checked
If isChecked = False Then
' Add non-checked boxes to context
e.WebTest.Context.Add(myContextParameter + "_" + _
tag.GetAttributeValueAsString("id"), "Is Not Checked")
e.Success = True
End If
End If
End If
Next
End If
If e.Success = True Then
e.Message = "Extracted check boxes."
Else
e.Message = "No check boxes extracted."
End If
End Sub
End Class
End Namespace
Inheritance Hierarchy
System.Object
Microsoft.VisualStudio.TestTools.WebTesting.ExtractionRule
Microsoft.VisualStudio.TestTools.WebTesting.Rules.ExtractAttributeValue
Microsoft.VisualStudio.TestTools.WebTesting.Rules.ExtractFormField
Microsoft.VisualStudio.TestTools.WebTesting.Rules.ExtractHiddenFields
Microsoft.VisualStudio.TestTools.WebTesting.Rules.ExtractHttpHeader
Microsoft.VisualStudio.TestTools.WebTesting.Rules.ExtractRegularExpression
Microsoft.VisualStudio.TestTools.WebTesting.Rules.ExtractText
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
See Also
Reference
Microsoft.VisualStudio.TestTools.WebTesting Namespace