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About Smart Client Script Player


Background

A Smart Client form can define a Launch Action to allow manually launching another form in the workspace.

For automated processes, Smart Client infrastructure provides three alternate actions which allow automating the selection of the next form to be launched;

  • Process Driven UI Action (PDUI)
       
  • Service Driven UI Action (SDUI)
         
  • Client Process Driven UI Action (CPDUI)

 

Process Driven UI Action (PDUI)

This action is used if the form launch is based on a process running on the server. This is typical to a Wizard Form which requires the process state to be maintained and communicated to either the launching form (or other forms subsequently posted) that might continue the process. The Order Management process is a good example for process driven UI.

 

Service Driven UI Action (SDUI)

This action is used if the next form to be posted depends on a UI driving service.

 

Client Process Driven UI Action (CPDUI) – Script Player

This action is used to drive a client side script player.  The process that maintains the state and drives the next form to be posted is a client side light weight process. The client who runs this light weight process is Amdocs Process Manager (APM) client.

Amdocs Process Manager (APM) Design tool is used to define the Script metadata. APM Client interacts with APM Server to get the metadata to the client and maintain the state.

The Client Process Driven UI (CPDUI) Action interacts with APM Client to launch Smart Client forms in the client workspace. These forms can be either dynamically constructed forms (E.g., Question and Answer script forms) or standard Smart Client forms already created at design time. These pre-designed Smart Client forms are invoked by a special script step known as Show page step)

The CPDUI Action communicates with APM client, to either start or proceed with a client process. Whenever the CPDUI needs user interaction, it yields back to itself and pass required inputs (process variables). The action processes the inputs and dynamically generates and posts a ‘script form’ for user response.

The target form can have another CPDUI action, which collects and validate user inputs associated with the action and submit the details back to the APM client.

To facilitate communication between the APM client and the CPDUI action, the process variables in the APM client are mapped (at design time) to the Data models in the next launched (target) form.

When APM client is running along with Smart Client, APM client interacts with APM server (via Smart Client and Smart Server) to get Light Weight Process metadata or to invoke a service (AIF service or any other service) as part of the process execution. In fact – The Smart Client acts as a host for running Light weight processes.

Smart Client normally uses a Submit Action to submit to the server and get the response back. This functionality is utilized for retrieving the metadata and invoking any server side service.

Similar to the PDUI action, the Client Process Driven UI Action launches a form based on the logical form name (LFN) input data section.  At script design time, the Script Designer refers the form’s input data section as show context area. At run time, any input retrieved from the process can overwrite the form’s default launch action properties.

 

Running Scripts from Smart Client form

Client Process Driven UI Action Can be added to any Smart Client form like any other action, and can be invoked by a user action or using application code.  The Client Process Driven UI Action defines various operations:

  • Get a lite process instance
        
  • Start running
        
  • Proceed
        
  • Abort
         
  • Go back (a process step)
        
  • Get log details

 

                                                                                                      Process Navigation

 

After getting response from the process, the Client Process Driven UI Action always invokes a launch action to launch a form based on inputs from the process, except when the process’ return status indicates abort/completed.

If the process returns with completed or aborted state, then it sends a message to its opener form indicating the new status. If this action is overloaded by a PDUI action, (in case the lite process was part of a server process), then, it invokes the dynamically created PDUI action and passes the ‘proceed context’ details (to allow the original server process continue).

The execution of the Client Process Driven UI Action is considered ‘done’ after the action launches the form or if the process is completed or cancelled and the action sends a message to its opener forms.

The action passes the Lite Process Instance (LPI) got from a “GetProcess” operation to all the launched forms. LPI is stored as a property of the launched Smart Client form to allow all CPDUI actions in that form access this Lite Process Instance.

While a Lite Process Instance is being executed, it may respond to one of the following UI steps:

  • Show page step
           
  • Prompt step

At runtime, the process might call for a UI step. This UI step can either a show page step or prompt step.

 

Show Page Step

A show page step dynamically invokes a Smart Client form by:

  • Creating a Launch action
          
  • Setting the launch action’s properties according to the properties provided by the process (in other words: it passes relevant process variables to the launch action properties)
         
  • Launching the target form (the target form is a standard Smart Client form which was previously set as a show page step in the process definition)
            
  • The show page can be invoked either in Synchronous orAsynchronous modes. In Synchronous mode, the Client action overloads existing actions in the form to return data back to Opener form (Script Player) which continues process. For example, clicking Save button in Show page form executes Save Actionand continues client process from Script Player form.An Asynchronous mode, returns data to Opener form right after the Initial Load Action of the Show page form is done and continues process

 

Prompt Page Step

A prompt step uses a dynamic form generator to create the prompt form.

  • The prompt form can be displayed either in the toolbox or workspace area (exact location is set at design time by the process designer
         
  • The prompt form is  based on the prompt info defined at design time in the process

 

 

                                                       Launch Script in Toolbox Area   

 

UifLiteProcessHost Class

The UifLiteProcessHost supports information storage (and retrieval) on the client’s disk. It also supports submitting server requests issued by the lite process instance.

The Smart Client RequestResponseManager is used to submit request to the server.

The UifLiteProcessHost provides the following functionality:

  • Get the required or latest version of lite process instance definition from the APM server and store it in the client
          
  • Submit an AIF operation request to the server based on the client host
         

To get a Lite process instance from the process definition, the Client Process Driven UI Action calls the static API getLiteProcInstFactory(), which returns a process instance factory which is used to create an instance of a Lite process instance.

For example, the action may use the following call to create an instance of the required process:

UifLiteProcessHost.getLiteProcInstFactory(procName, version, deployCount().create().

 

Lite process instance

A Lite process instance is an instance of a lite process definition downloaded from the APM server. The client can run multiple instance of the same process definition at the same time.

For example, when user runs ‘Script A’ once, an instance of Script A’s LiteProcInst is created and used until the script is done.

 

Types of Operations

GetProcess

The inputs to get a client lite weight process are Process Name (mandatory) and Process version – (optional); If not provided, the latest version of the process is used.

Accessing a client process involves getting the LiteProcInst (LPI) based on the lite process definition retrieved from the relevant APM client (CRM) database or from APM server.

After getting the LPI, the defaultLaunchAction specified in the action is invoked. The default Launch Action should give a valid Logical File Name with any required input data.

Additional input required for the process is information regarding the launched form; whether the form should be launched as a Main WORKAREA form or as a TOOLBOX form.

The action fires an event including this information to the application code before launching the defaultLaunchAction. This allows the application code to take advantage of both potentially adding a LaunchMapItem, and pass this as an input to the launched form and use form version selector, which could return the appropriate physical form name to be launched on the WORKAREA or TOOLBOX.

 

Single light process instance per form

When launching the form (executing the defaultLaunchAction), the LPI instance is passed internally through the launch action to the launched form and cached. Any other CPDUI action in the launched form will always use this LPI instance for any other operation involving the same process, which means only a single lite process instance can be used on a form.

Consider an example where the launching form is a Script listing form and the user selects a particular script and clicks play. The play button will be associated with the CPDUI action that has:

  • Operation:                                 “GetProcess”
         
  • DefaultLaunchAction:   launch action where LFN = “

The Client Process Driven UI Action retrieves the Lite process Instance and the target launch area (where to launch this form – WORKAREA or TOOLBOX).

The CPDUI pass this information to the defaultLaunchAction and executes the launch action. The launch action launches the script player form, and sets this Light Process Instance to scriptPlayerForm.LiteProcInst.

If the client process was part of a server process, then PDUI action would dynamically create this action with operation “GetProcess” and use the ShowContext details to get the process name version etc.

As already mention, the Launch action would pass the Show context data and Proceed Context data to the launched form, and if required, overload any existing action in the launched form as described by the Action descriptor. The Proceed Context can be passed back to the server after the client process is done.

 

Start, Proceed, Back, Abort, Restart, ShowLog

All operations other than “GetProcess” should not provide the process name, version as input. If the action’s operation type is set to one of Start, Proceed, Back, Abort, Restart or ShowLog, then the default Lite Process Instance which is already available in the Form (where the action is defined) is used.

LiteProcInst provides APIs to run, proceed, back, cancel the process, which is used to perform the operation.

Restart

Restarting the client process has to clear out the logs created so far, and initiates the process as if nothing happened in this process instance. A process can be restarted before it is complete. It can be done even after a child script is executed, in which case it goes back to the main process that was originally started by the user. Restarting is not possible, after a show page step.

Abort

Aborting a process also requires a Feedback message from the user. It’s up to the application to get this feedback and set it to the action if the operation = “Abort”

ShowLog

Calling the below API on the liteProcInst gets the log details.

LiteProcInst.getLiteProcInstHistory()

The output from the API can be set to a data model in the launched form and displayed as a list (See output processing below).

01/07/2011 Posted by | Amdocs, APM, CRM, CRM, Customer Interaction Management, Development, Front End, Smart Client, Technology | Leave a comment

Using Paths and Expressions in Smart Client


Smart Client Run-Time Focus Objects  

Smart Client Named Collections

Named Collection data path handler enables resolving an item by name within a named collection, such as

 $Form:Controlset:Controls:MyDateControl

 

Named Collection Data Paths

 A named element in a collection can be extracted from a java object by using two path items:

  • The first identifies the collection,
  • The second identifies the item’s name

 

 An example data path is as follows:

$Dataset:DataModel:myDataModel

The $Dataset context type contains a collection that can be accessed by:

getDataModelByName("myDataModel")

 

The followings Smart Client runtime elements are implemented as Named Collections:

 

Example:

The following path resolves to a Grid column control in the current Form using Named Collection:

 $Form:ControlSet:Control:caseOverviewGrid:GridColumn:caseTitleCol:ColumnControl

where:

  • Form                         is the starting context and it specifies a UifForm context type
  • ControlSet                 is a member in UifForm
  • Control                      is the accessor collection name for ControlSet
  • caseOverviewGrid       is the name of the Grid control
  • GridColumn                is the accessor collection name for the caseOverviewGrid object
  • caseTitleCol               is the name of GridColumn inside the caseOverviewGrid grid control
  • ColumnControl           is a property in GridColumn which specifies the contained UifControl for the     GridColumn control.

 

Example:

The following path resolves to a logical form called com.nextgen.GlobalUtils:

 $Workspace:Form:com.nextgen.GlobalUtils

where

  • Workspace                           is the starting context and it specifies a Workspace context type
  • Form                                   is the accessor collection name for Workspace
  • com.nextgen.GlobalUtils         is the name of the Form.

 

Data Path Contexts

Data Model,  Data Provider

 

Form,  Control,  Action

 

                               Create Data Request Map

 

                                Choice List Action Request Map

 

Input, Workspace, Locale, WorkspaceForm

 

 

 

 

ContainingFormDataModel,  OpenerFormDataModel,  TopLevelFormDataModel,  Form

 

  

ServiceInput, ServiceOutput,  Bindable, Control, DataModel, Input, Relative

 

13/05/2011 Posted by | Amdocs, APM, CRM, CRM, Development, Front End, OSS, Smart Client, Technology, Uncategorized | Leave a comment

Using Expressions (Part 3)


About Expressions

An expression is a single Boolean or arithmetic expression that can be evaluated by a special expression evaluation class. The operands in an expression are literals (numbers and strings), paths or functions.

An expression string is analogous to an Excel formula. It encapsules logic, data access, calculations etc

sub-expressions mechanism allows an expression to be defined once with a known name, and then re-used in other expressions.

Expression examples:

$Focus:site2contact_role(primary_site=1):role_name = ‘Employee’
dateAdd(‘d’, $Focus:required_date, 3)
If ($Var:Churn = ‘High’) then ‘Gold’ else ‘Silver’

 

Expressions are a generalisation of the path concept that has always been in Clarify. There are several places in the application where a Boolean expression is stored in the database in three fields – path, operator and value. Expressions are stored as a single text field, containing the expression. All string comparisons are case insensitive.

Expression use ‘contexts’ to read and write data. Its syntax includes functions, operators, operands, logical tests and  literals. They can be created dynamically at runtime.

 

Where Expressions are Used

  • Extensively used by Amdocs Process Manager
      
  • Input parameters for Services (Process Manager and Rule Manager)
     
  • Order Management Standard Edition Eligibility rules
      
  • Role Based Authorization
      
  • Flexible Attributes Templates
     

 

How Expressions are Used inby APM

  • Most places in APM that expose properties that are used directly at runtime
        
  • Operation inputs / outputs
       
  • Pre and post data assignment
       
  • Conditional junctions
      
  • Flows
       
  • Dynamic subprocess
      
  • Dynamic service
     

 

Why Use Expressions?

Expressions encapsulate business logic easily without implementing complex processes. The processes become easier to build, manage, understand and maintain.

Expressions provide improved runtime performance and ease of monitoring

Expressions overcome various Process Manager constraints. Business processes become easier to build, manage, understand and maintain by reducing need to extend code or datamodel.

Expression allow using user-friendly naming, easier implementation and testing

 

Expression Syntax

Expressions combine operands which take the form of paths, literals or other expressions.

Examples:

$Focus:subcase2case:casereporter2contact:first_name
‘Billing Dispute’
?Sales.GetLeadTime
$Var:ContactObjid

 

The following describes an expression. Uppercase and quoted elements are lexical constants.
Keywords are case-sensitive:

Examples:

not ($Var:Score > 0)
5 * ($Focus:score + 1)

 

Binary operators

The values for OP are supported, shown in order of precedence:

 

  • Strings are delimited by single quotes
       
  • String Concatenation ( + )
       
  • Escape ( \ ) characters: Newline ( \n ), Return ( \r ), Tab ( \t ), Single quote ( \’ )
       
  • Constants:  Boolean true ( true ), Boolean false ( false ), Null ( null )
      

 

Examples:

if ($Var:CaseType contains 'Sales')
then
‘Sales Queue’
else
‘Support Queue’

 

Unary operators

The values for UNARY are ‘-‘ and ‘NOT’.

Unary has a higher precedence than OP.

 

Functions

ANY, EVERY

any(<Collection-Path>, ‘$IterativeContextName’, exp)
every(<Collection-Path>, ‘$IterativeContextName’, exp)

Takes a Collection-path which returns an array of objects (i.e com.clarify.webframework.CdoCol), iterates through each element from the array and assigning the element from the array to the context named $IterativeContextName.

Then it evaluates the expression which may contain a DataPath with a context name of $IterativeContextName.

The any function iterates over the row, access a value from each row and evaluates the value against some rule specified in the any function. As soon as a row from the table whose values cause the rule to evaluate to true, any function will return immediately with a true.

The every function is the opposite of any function. As soon as a row from the table whose values cause the rule to evaluate to non-true, every function will return immediately with a false.

The countWhere function iterates through each element in the Collection and for each element, applies the element from the context to the Expression and increments the total count value by 1 if the Expression evaluates to a boolean true, else no increment. The result from countWhere is an Integer object.

any, countWhere and every take a Collection-path which returns an array of objects or a com.clarify.webframework.CdoCol, iterates through each element from the array and assigning the element from the array to the context named $IterativeContextName. Then it evaluates the expression which may contain a DataPath with a context name of $IterativeContextName. Multiple any/every functions are allowed in a single expression.

 

Return value

any and every returns a Boolean object

countWhere returns a Integer object.

If the Collection-path returns a CdoCol, then to address the individual Cdo within the expression, the Path must be prefixed as follows:

$IterativeContextName:CdoColName:<Path>

 

If the Collection-Path expression returns null or unknown is set as a result of evaluating the expression, then unknown will be set to true and a Boolean false with be returned.

The following rules determine the return value for any function:

 

The following rules determine the return value for every function:

any($Focus:case2subcase, ‘$subcase’, $subcase:status2gbst_elm = ‘Open’)

 

Count Functions

count( exp )

Takes an expression returning a row set, and returns the count of rows.

 

countFlex(exp)

Returns number of defined flexible attributes based on flags value.

Please see bellow for more details.

 

countWhere(<Collection-Path>, ‘IterativeContextName’, exp)

Iterates through each element in the Collection and for each element, applies the element from the context to the Expression and increments the total count value by 1 if the Expression evaluates to a boolean true, else no increment. 

 

Date Functions

currentDate()

Returns the current date/time, using Session.getCurrentDate().

 

dateAdd( units, date, interval )

Add a number of units to a Calendar. Default is seconds
Interval: y (years), m (months), d (days), h (hours), n (minutes), s (seconds)

Example:

dateAdd(‘d’, currentDate(), 3)
 

dateDiff( units, startdate, enddate )

Subtract two dates, returning a signed number of units, default is seconds.

  

 

Test Functions

isNumber( exp )

Returns true if the expression is numeric according to Session.fromString(cboTypeDecimal)

 

isNull(exp)

Returns true if the expression is null

 

isUnknown( exp )

Returns true if the expression is unknown (see below)

 

Conversion Functions

toNumber( exp )

Convert the expression to a number – expression should be a string or a number.

Uses Session.fromString(cboTypeDecimal)

 

toDate( exp )

Convert the expression to a Calendar.

Expression should be a string or a date. Uses Session.fromString(cbotypeDateTime)

 

toJavaDate( exp )

Convert the expression to a Date. Expression should be a string or a Calendar. Similar to toDate but returns value as a Date.

 

toDisplayString(exp1, exp2, exp3)

Converts the expression (exp1) to a localized string. Exp2 and exp3 are optional parameters.

If the object type for exp1 are: GregorianCalendar or Date Java class, then Session.toDateString is called.

Exp2 will be PictureString parameter. If Exp3 is specified, then it will be the MaskString parameter.

 

If the object type for exp1 is Money object, then Session.toCurrencyString is called.

If the object type for exp1 are BigDecimal, Float, Integer or Double, then Session.toNumberString is called.

Otherwise, the default toString() is returned

 

toFocusObject(exp1, exp2)

Convert arbitrary strings to Focus Object.

toFocusObject function can be used to convert arbitrary strings to Focus Object for passing to services.

Exp1: can be either a database Object Name or an expression. If it is expression then it should be given in such a way that the evaluated result value of this parameter should resolve to a DB Object Name.

Exp2: can be either a DB Objid or an expression.  If it is an expression then it should be given in such a way that the evaluated result value of this parameter should resolve to an Objid of the row in the corresponding table.  

toFocusObject function takes 2 parameters. These parameters can be either expressions or they may be just a table name and Objid. If the parameters are expressions then it will evaluate these expressions and constructs a new Focus Object based on the evaluated values of the input parameters.

Input expressions should be evaluated to the proper table name and corresponding Objid of the row. The return value of this function will be a FocusObject of type com.clarify.sam.FocusObjectImpl.  It returns null if there is any exception.

Examples

A:        toFocusObject ('user', $case:case_wip2wipbin:wipbin_owner2user:objid)

The above expression returns a focus object of type “user”

 

B:        toFocusObject ('con’ + ’tact', $case:case_reporter2contact:objid)

The above expression returns a focus object of type “contact”

 

     If we know the Objid of the focus object then we can also specify toFocusObject function like below:

C:        toFocusObject ('contact',  ‘268435501’)

The above expression returns a focus object of type “contact” which will have the table name as ‘contact’ and Objid as ‘268435501’

 

    Site which has an objid from CDO / XVO

D:         toFocusObject(‘site’, $Cdo:myCdoVariable:siteObjid)

                CDO to XVO type conversion is already supported, so a real bona-fide site CDO could be passed
                where an XVO parameter is needed.

 

toString( exp )

Convert an expression to a string. Uses Session.toString.

 

toInteger( exp )

Take the integer result of an expression, discarding the fractional part.

 

 

Date Intervals

The intervals for date calculations are one of the following:

y (years), m (months), d(days), h (hours), n(minutes), s (seconds = default)

 

 

Constants

Constants are defined as numeric, or string.

  1. All numeric constants must be represented in locale independent format.
     
  2. All string literal must be represented in locale independent format.
     
  3. String must be delimited single quotes (‘’). The following escape sequences may be embedded inside a string:  \n \r \t  \’
     
  4. #<nmToken> is identified as string literal whose value will be looked up in table_string_db in current locale using <nmToken>. Exception are thrown if lookup is failed.
     
  5. true is used to represent Boolean true value
     
  6. false is used to represent Boolean false value
     
  7. null is the null value
     

 

 

Null values

Experssion returns Java null in the following conditions:

If <operand1> then < operand2> else < operand3>
  • operand1 is not a Boolean class
     
  • operand1 is  a Boolean class and operand2 or operand3 is a null< operand1> AddOp < operand2>
    < operand1> MultOp < operand2>
  • operand1 is null and operator is Mul/Div/Mod.
      
  • operand1 is null and operator is Add/Sub and operand2 is null
       
  • operand1 is not null and operand2 is null and operator is Add/Sub/Div/Mod
       
  • operand1 is not null and operand2 is null and operator is Mul
     

 

Unary < operand >

Operand is NULL

 

Named Expression

Named Expression evaluates to NULL

 

Constant

Constant is a Null Literal

 

DataPath Value

A CboError from DataPath or DataPath returns a null as a value

  

Unknown values

There are some circumstances where a path cannot be evaluated. In these cases, the result of the expression is not known. For certain cases, it may be possible to default a value (for example Process Manager returns the first row when multiple rows are returned when a single row is expected).

  

Examples

  • A single row is called for, but multiple rows are returned. For example, a path traverses a one-to-many relation with no qualifier, and is not used in a Count() function.  The first value returned by the database read is returned – the value is known
  • No database row is returned         –      A relation is not set (Data path returns null value)
     
  • The field or item is not defined    –      A path tries to access a field (e.g. in a CDO or CBO),   property or attribute that is not defined.
      
  • Flexible attribute not defined      –     The path refers to a flexible attribute that does not exist
  • DataPath returns null value          –     A data path that returns a null value is also considered an  unknown value

 

When a path cannot be resolved, it will have the value unknown. Any expression involving an unknown value becomes unknown. Unknown is returned from the expression evaluator.

 

Exceptions

The followings list the exception type and conditions under which exceptions will be thrown by Expr.

 

Using Expressions – Examples

  1. The Collection-Path is a hashmap that points to an array of hashmap. ‘Tables’ is a key in the contextMap and the value of ‘Tables’ points to a HashMap called Tables.The TablesHashMap has a key called ‘Products’ whose the value is an array of hashmap.
         

       
         
    The following illustrates an example on how to setup the contextMap properly:
           

              
           
             
     The context “Tables” from above is setup similar to a database table as follows:
      

        
        
  2. The collection-path is a hashmapthat points to an array of Focus objects. ‘NewCases’ is a key in the ‘Row’ hashmap and the value of ‘NewCases’ is an array of Focus objects which points to a case object.The following illustrates an example on how to setup the contextMap properly:
          

      
         
             
  3. The collection-path is a rowset path that returns an array of Focus objects (which points to a site schema type).
    $Focus is set to a case object.
            

          
      
               
  4. The collection-path, $CdoCases:openCases, returns a CdoCol which constains a collection of Cdo objects. $CdoCases is set to a CdoManager in the contextMap.

        
      
     The following illustrates an example on how to setup the contextMap properly:
        

        
         
  5. The example illustrates how to use countWhere. Using the context “Tables” from example1, the following countWhere expressions returns:
               

  

  

countFlex Syntax:    countFlex(Path [, eflags [, enumType])

Path is a DataPath that returns a valid focus object (with valid DbObjectName and objid). If an array of focus objects are return, countFlex returns the count for the first element from the array.
If Path is the only parameter specified, then it returns the number of defined flexible attributes.

            

eflags is an optional parameter, if specified, returns the number of defined flexible attributes whose flexible definition flags value matches (bitwise) with eflags. eflags can be any expression.
If eflags < 0, then eflags is ignored.

    
       

enumType is an optional parameter and have one of the following values:

If enumType is not one of the above values, then the set should be the defined flexible attributes set.

If enumType and eflags are defined and have valid values, then the flexible attributes set defined by enumType should be used to match against the eflags value.

 

Return Value

If Path evaluates to a valid path and focus object returns a valid object, then a count value is returned, else a null is returned and Unknown is set to true.

The followings list the exception type and conditions under which exceptions will be thrown by Expr.

 

Examples:

1)    $Site points to a site Focus object. 

countFlex returns the number of defined flexible attributes.

countFlex($Site)

2)    $Focus points to an order_action Focus object. countFlex returns the number of defined flexible attributes
        with eflags bit 8 (External System) set.

countFlex($Focus, 08)

3)     The first element from the Focus array should be used to evalaute against the eflags value
         (pre and post set). The flexible attribute set is restricted to attributes which have Data.

countFlex( $OpenCase:case_reporter2subcase, 3, cboConstants.cboFieldSetHasData )
 

 

 

Named Expressions

In order to facilitate an easy to use end user interface, expressions are able to contain named-expressions, stored in the database.

A named-expression is denoted by a domain and a name.

Optional parameter(s) can be specified with named-expression. The domain is a logical grouping of named-expressions to enable different applications of the same name. Recursive Named Expression is not supported.

The syntax is:

? domain.name(<ParamName>:=expression,...)

 

Named expression is an expression that has been defined in the database. Use the CRM Administrator module to manage Named Expressions

 Syntax:

?[Domain].[Name]
  • Domain        – logical grouping
  • Name           – User-friendly name
  • Expression   – the actual expression itself

 

Example:

?Sales.TaskDueDate

   

Named Expression Parameters

 

Overview

The Named Expressions parameters mechanism addresses the following:

  1. Use multiple parameters syntactically
       
  2. Support parameter type checking during Expr evaluation phase
         
  3. Support UI design time type validation for parameters
       
  4. Support UI design time retrieval of parameter list for a given Named Expression
       

 

Parameterized Named Expression Syntax

?domain.name( <ParamName> :=expression, ...)

<ParamName> is the parameter name.

Multiple parameterized Named Expressions are allowed inside a single expression, but all ParamName must be unique within the Named Expression. Parameter name/value pairs are mandatory.

For basic Java type (java.*), Expression do type checking and conversion to the type as defined in TABLE_EXPR.Type and throws an error if type checking or conversion fails.

For non basic Java types, Expression just do type checking.

    

The followings list the exception type and conditions under which the exception is thrown by Expr during the prepare phase:

 

 

Parameter Binding Variable Syntax

To facilitate binding the identifiers from the Named Expression to the actual expression text defined in table_expr.Expr, parameter binding variables are created.

The syntax for parameter binding variable is:

$Param: ParamName
 
 

Database Schema Definition

Expression information is stored in table_expr as follows:

TABLE_EXPR

 

 

Parameter information is stored in table_expr_param as follows:

TABLE_EXPR_PARAM

 

 

 

Optional Parameters in Named Expressions

This feature allows named expressions to contain optional parameters, which means if any parameter is not specified in the named expression, then default value of the parameter will be substituted in the missing parameter. If the default value cannot be converted to the expected data type then the result of the expression will be unknown.

While parsing the sub expression, if parser finds any parameter is missing then it tries to get the specified default parameter value from table EXPR_PARAM.default_value. If it finds any default value for the missing parameter then it substitutes the default value in the missing parameter. If the default value cannot be converted to the expected data type then the result of the expression will be unknown. 

Suppose existing expression component handles named expression like:

?morder.isHandset(Territory:=’EastCoast’, DeptId:=12)
 

Optional parameter feature allows the above expression to be specified in the following ways:

?morder.isHandset(Territory:=’EastCoast’, DeptId:=12 )

The above expression is same as the expression without optional parameter.

 

?morder.isHandset(Territory:=’EastCoast’)

The above expression assumes the default value of parameter DeptId is specified in the database.

 

?morder.isHandset(DeptId:=12)

The above expression assumes the default value of parameter Territory is specified in the database.

   

?morder.isHandset

The above expression assumes the default values of parameters Territory and DeptId is specified in the database.

 

 

Dynamic Expressions

Dynamic path modifiers,  the Path modifier determined at runtime.

Usage:

A value assigned to the $Var.

Assign ‘C123’ to $Var:SubCaseId

 

The $Var is used in the iteration

$Focus:case2subcase:case(id=$Var:SubCaseId):title

 

Reference Path

An expression that points to a path

Build the path:

  • Set the process variable CasePath with the contents of Case title field.
  • Case record is identified by the variable CaseObjid:
Assign ‘$Db:case(objid=’ + $Var:CaseObjid + ‘):title’ to $Var:CasePath
 

Use the path:

$$Var:CasePath
$Db:case(objid=2435463534):title
 
 

Caching iterative data path values inside array functions

Expr object contains an array of objects which hold cached data path values.  Attempt to get data path value from cache, if not present, and then cache it. Incrementally cache data path array values as they are iterated over.

The cache is optimized — if data path values are not reused within the expression, then they are not cached.  However it may not be possible to predetermine if data path values will be reused (e.g. reference path) so must cache it those cases.

 

Background

Array functions like ‘any’ and ‘every’ are iterates over the row, access a value from each row and evaluates the value against some rule specified in the function.  When it iterates over the row the condition (rule) may have an expression and expression may refer to the same data path more than once. In these cases currently, when each time it encounters the same data path in the condition it calls Datapath.readItem API to read the path value.

By caching the data path value once it read, then the next time when it sees the same data path in the condition (rule) then it will get the path value from the cache instead of calling Datapath.readItem API, so the performance of expression evaluation can be improved while handling array functions.

 

Summary

While evaluating array function, when it first time encounters a data path in the condition it gets the path value by calling Datapath.readItem API and stores data path value in cache. It uses the key as a combination of Collection-Path plus column name of IterativeContextName plus iteration row number.

For example, in the following example ‘every’ function iterates through each row and executes the rule.  In this example data path  $eachcase:title is refereed twice, so while executing each row first time it gets the path value by calling readItem API and stores it in the cache, then from the second time onwards for the same data path  it gets the path value from cache.

every($Row:case, '$eachcase', ($eachcase:title = 'Test LAB') or ($eachcase:title+'-'+'LAB Test' = 'First case from thin client-LAB Test'))

Cache will be cleared once the expression is evaluated and its lifetime is only for the current expression.

 

 

Next Part:   Using Paths and Expressions in Smart Client

 
 
 

  

12/05/2011 Posted by | Amdocs, APM, Backend, CRM, Development, Front End, Smart Client, Technology | | Leave a comment

   

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