eValid™ -- Automated Web Quality Solution Browser-Based, Client-Side, Functional Testing & Validation, Load & Performance Tuning, Page Timing, Website Analysis, and Rich Internet Application Monitoring. © Copyright 2000-2008 by Software Research, Inc.

Introduction
The term Adaptive Playback refers to eValid's ability to modify its playback behavior to track changes made by the WebSite server in the pages delivered. This feature permits certain types of scripts, and certain actions within those scripts, to play back reliably even when there are small variations in the actual pages generated and delivered to eValid for processing.

Example
Suppose you are testing the ability of a user to search for a particular item on your site. When you make your eValid recording the WebSite server generates a page that has a certain number of possible responses, from which you pick one by name. Later, when more items are added to the possible selections, you want playback to pick the same item.

Examples of WebSites that dynamically update their HTML pages regularly are:

• Sites that provide Airline or other transport availability information.
• Sites that maintain and update a database of, for example, club membership names.
• Shopping sites where prices changes, items come into or go out of stock, etc..
• Stock Market sites were price quotations changes rapidly.

Adaptive Playback is intended for use specifically with dynamically HTML.

Description
Adaptive Playback works with recordings that involve link navigation (such as FollowLink, or GoToLink) or with such commands as InputImageClick, and InputValue.

During playback eValid, using Adaptive Playback technology, first attempts to match the requested element at the recorded page index. If that matches, then eValid sets the value as specified or clicks the button/image as required.

If the visible text for a link does not match [compared with what was recorded] then eValid will search the page for a link with the same visible text and the same base URL. If it finds a match, then eValid clicks on that URL and makes an appropriate note in the LogFiles.

If eValid does not find a match, it issues an ERROR message to the user and the playback then fails at that point (or until the next GoTo command).

The current HTML page does not have to be identical in structure to the one that was used during the recording process. With eValid's Adaptive Playback technology the page can be can be "close enough" so that the playback is reliable even with changes.

Technical Details
Below is when eValid performs an adaptive search, and what it looks for:

Applicable Commands
Not every eValid command has Adaptive Playback. This table shows the eValid commands that are endowed with Adaptive Playback capabilities.

Limitations and Restrictions
Each INPUT element on the page must have a unique name/value pair. If a name/pair is duplicated (i.e. if the name/value pair is not unique) then adaptive playback will not succeed.

Feature Architecture Comments
The proprietary adaptive playback features in eValid represent a careful compromise between doing what was originally intended and expected, and doing what makes sense to do even if the playback is not perfect.

The adaptive playback implementation and behavior varies on a case by case (object type by object type) basis. As a general rule preference in eValid adaptive playback actions is given to these factors, in the following decreasing priority:

1. The visible text on the screen.
2. The underlying case-sensitive URL or action type for the associated object.
3. The physical index/location of the object.
4. The actual properties of the object.

Remember, however, that a test playback that adapts too extensively to an altered page loses its value as an indicator of major change and possible failure.

If the adaptive playback feature fails to adapt enough for your situation or needs, you may wish to set up an OnWarningGoScript in your playback script to transfer playback control to a recovery script where appropriate corrective action can be taken.