eValid™ -- Automated Web Quality Solution Browser-Based, Client-Side, Functional Testing & Validation, Load & Performance Tuning, Page Timing, Website Analysis, and Rich Internet Application Monitoring.

Summary
eValid performs parameter string substitutions within parameterized scripts in several modes:

• Functional Test Playbacks,
  using the GoScript $NAME=value [ $NAME=value] structure.
• Data Synthesis Mode,
  in which each line of $NAME=value [ $NAME=value] string substitution pairs is used for each instance of eValid playback of the parameterized script.
• LoadTest Scripts (see example below),
  in which individual _eValid sub-browser invocations can have scripts modified with "$NAME=value [ $NAME=value]" structures.

Example
The eValid string substitution process works both in regular scripts (via CallScript commands) AND in LoadTest scripts, where string substituion is also commonly applied.

In a typical LoadTest script such as shown below, you can see how the $Name=value feature is used to automatically modify playback scripts to account for minor variations between individual playbacks (Special Character Treatment).

   
    #
    #  Sample scenario script for eValid
    #
    ProjectID "Test"
    GroupID "Load"
    TestID "Scenario_01"

    _eValid "script1.evs" "Simplest"      60   "$LOGIN=jones $PASSWD=bill" "-pm 0.9"
    _eValid "script2.evs" "Not So Simple" 90   "$ACCT=Smith $PASSWD=Any"   ""
    _eValid "script3.evs" "Type A User"   50   "$USERID=Andrew"            ""
    _eValid "script3.evs" "Fast Type A"   1200 "$USERID=Jane"              "-pm 0.5"  
    _eValid "script3.evs" "Type A User"   80   "$USERID=Eddy"              ""

    _eValid "script3.evs" "Slow Type A"   40   ""                          "-pm 2.25"
    _eValid "script4.evs" "Type B User"   70   ""                          "-pm 1.0" 
    _eValid "script5.evs" "Type C Buyer"  100  "$ACCT=smith"               "-pm 1.0"
    _eValid "script5.evs" "Type C Buyer"  150  "$ACCT=jones"               "-pm 0.2"
    _eValid "script6.evs" "Background"    300  ""                          ""
  

In this example LoadTest scenario, the script script1.evs has the value jones substituted for instances of $LOGIN that have been included in it. Later on, the script script5.evs has the name smith substituted for all instances of the string parameter $ACCT.

Usage and Limitations
Here are the syntax and semantics rules for string/parameter substitution in eValid.

• Syntax Description. The general syntax for a string substitution is "$NAME=value [ $NAME=value]", where the [ ]'s indicate zero or more instances of string substitutions. String substitutions appear as blank-separated substrings.

  You can have any number of string substitutions, each $NAME=value [ $NAME=value] pair separated by blanks and all enclosed in "'s.

• Syntax is Not Checked. If there are errors in the syntax in the parameterized script then the substitutions are ignored without warning.

• Undefined Instances Not Checked. If you have $NAME's defined in a script and these parameters are not assigned a value they are not modified. Such names likely will result in failed playbacks. In other words, it's ok to have extra $NAME's in your script but caution is advised.

• String Substitution is Done Only Once. Name value pairs assign specific values to the parameters in this script. Assignment of specified values is made at the start of the test with string substitution of each instance of $NAME found in the script file with the value. The script file is not altered in this process.

• String Names, Values Case Sensitive. $LOGIN is not the same as $Login. Both names and values are case sensitive.

• Special Character Treatment. String values cannot have blanks or certain special characters, except as described as follows. To include a special character in a value string you must include the indicated %number.

  Symbol	Meaning
  %20	(Blank Space)
  %22	"
  %24	$
  %25	%
  %3D	= (Equal Sign)
  %3d	= (Equal Sign, Lower Case Version)
  %0D	\n (Newline)
  %0d	\n (Newline Lower Case Version)

• No Matches Found Means Nothing Is Changed. If $NAME is not found in the script, for whatever reason, no substitution is made. In other words $NAME=value assignments that aren't meaningful to the current script are ignored.

• Multiple Matches in Script are Permitted. If $NAME is found multiple times in the script, multiple substitutions are made. There is no limit on the number of $NAME=value pairs that can be used. $NAME=value

• Multiple Specifications are Permitted. The same $NAME may occur multiple times in the parameter list, but only the first value assigned to it has any effect.

• Improving Readability. Blank spaces can be used to separate the name value pairs to render the sequence of replacements more readable.

• Only One Pass Is Made, Top Down and from Left to Right. Only one pass through the target script file is made. The scan begins at the top and proceeds line by line left to right.

• Names Should Be Unique. If you have a parameterized script which includes both $NAME and $NAMEONE, and if you substitute $NAME=firstname then instances of $NAMEONE will be replaced with firstnameONE if the definition $NAME=firstname appears before an assignment of $NAMEONE=something. String substitutions are on a "first come first served" basis, and the possibility of one name being a subset of another name is not checked.

• Script Lines May Not Be Continued. Event though eValid inserts backslashes in some cases to improve readabilty in output script files, the string macro-substitution utility needs to have full, non-continued lines. Join continued lines before processing parametric scripts.