Variables, Buttons and Keys

Variables, Buttons and Keys

Introduction

 A Variable is a storage location or an entity. It is a value that can change, depending on the conditions or on the information passed to the program. The actions in TDL can be delivered in three ways: by activating a Menu Item, by pressing a Key or by activating a Button. The definitions of both Buttons and Keys are the same, but at the time of deployment, Keys differ from Buttons.

Variable

In TDL, a Variable is one of the important definitions, since it helps to control the behaviour of Reports and their contents. Variables assume different values during execution and these values affect the behaviour of the Reports. A Variable definition is similar to any other definition.

 Syntax [Variable : Variable Name]

Attribute : Value A Variable should be given a meaningful name which determines its purpose.

Attributes of a Variable

The attributes of a Variable determine its nature and behaviour. Some of the widely used attributes are discussed below: Type This attribute determines the Type of the value that will be held by the variable. The Types of values that a variable can handle are String, Logical, Date and Number. In the absence of this attribute, a variable assumes to be of the Type String, by default.

Syntax [Variable : Variable Name]

    Type : Data Type

Example: [Variable : ICFG Supplementary]

          Type : Logical

A logical variable ICFG Supplementary is defined and used to control the behaviour of certain reports, based on its logical value, as configured by the user.

Default

This attribute is used to assign a default value to a variable, based on the ‘Type’ defined.

 Syntax [Variable : Variable Name]

Default : Initial Value

Value of the variable should adhere to the data type specified with ‘Type’ Attribute.

 Example: [Variable : DSP HasColumnTotal]

Type : Logical Default : Yes

The Default Initial Value for the logical Variable DSP HasColumnTotal is set to YES. This variable will begin with an initial value YES in the Reports, unless overridden by the System Formula. We will learn about the System Formula in the coming sections.

 Persistent
This attribute decides the retention periodicity of the attribute. If the attribute ‘Persistent’ is set to YES, then the latest value of the variable will be retained across the sessions, provided the variable is not a local variable. We will learn about the concept of local and global variables shortly. Syntax [Variable : Variable Name]

 Persistent : Logical Value

 Example: [Variable : SV Backup Path]

Type : String Persistent : Yes

The attribute ‘Persistent’ of the variable SV Backup Path has been set to YES, which means that it retains the latest path given by the user even during the concurrent sessions of Tally.

Volatile

 In cases where the ‘Volatile’ attribute in the Variable definition is set to YES, the variable is capable of retaining multiple values, i.e., its original value with its subsequent values, are stored as a stack. The default value of this attribute is YES. In cases where a new report R2 is initiated, using a volatile variable V, from the current report R1, the current value of the volatile variable will be saved as in a stack, and the variable can assume a new value in the new report R2. Once the previous report R1 is returned back from the report R2, the previous value of the variable will be restored. A classic example of this is a drill-down Trial Balance.

SyntaxVariable,

[Variable : Variable Name]

Volatile : Logical Value

Example: [Variable : GroupName]

Type : String Volatile : Yes

The ‘Volatile’ attribute of Group Name Variable is set to YES, which means that the variable ‘Group Name’ can store multiple values, which have been received from multiple reports.

Repeat 
This attribute is mainly used to achieve the Auto Column behaviour in various Reports. Each Column is created with a subsequent Object in a Collection automatically, till all the columns required for Auto Columns exhaust. The ‘Repeat’ attribute has its value as a variable which has the collection of Objects, for which the columns need to be generated. Every time the Repeat is executed, the column for the subsequent Object is added.

Syntax [Variable : Variable Name]

 Repeat : Variable Value

 Example: [Variable : SV FromDate]

Type : Date Volatile : Yes

Repeat : ##DSPRepeatCollection

##DSPRepeatCollection Variable receives the Collection Name from a Child Report, which accepts inputs from the user regarding the columns required. Variable SVFromDate gets repeated over the subsequent period in the Collection each time the column repeats.

 The Scope of a Variable

The scope of a Variable can be broadly classified as follows:

p Local

p Global

p Field acting as a variable

Local

A Variable is termed as a local variable when it is associated to a Report. This means that the scope of the variable covers only the current report and its components. It is not mandatory for local variables to have an initial value. Syntax [Report : Report Name]

Variable : Variable Name

Example: [Report : Balance Sheet]

 Variable : Explode Flag

Explode Flag Variable is made local to the Report ‘Balance Sheet’ by associating it using the Report attribute ‘Variable’.This variable retains its value as long as we work with this Report. On exiting the Report, the original value if given, is returned and the value modified within this report is lost. For example, consider a situation where ‘Stock Summary’ Report is being viewed with Opening, Inwards, Outwards and Closing Columns enabled through Configuration settings. Once we quit this Report and re-enter the Report, the variables return to the default settings.

Global A variable is termed as Global variable when it is defined under System Variable section. It means that the scope of the variable covers all reports. An initial value is mandatory for global variables.

Syntax [System : Variable]

Variable : Initial Type Based Value

 Example: [System : Variable]

 BSVerticalFlag : No

The BSVerticalFlag Variable is made Global. Hence, this variable value being modified in a Report is retained, even after we quit and re-enter the Report. The retention of a Global Variable can be done on two levels, i.e., either within the current session or across the sessions. If the Variable attribute ‘Persistent’ is set to YES, then the modified variable value is retained across the sessions, else the value defaults back to initial value on re-entering another session of Tally.

Field Acting as a Variable 
The Variable attribute in a ‘Field’ Definition is used to make the Field behave as a Variable. when value is entered/altered in a Field, the variable assumes the same value with immediate effect. The Variable need not be defined previously, since it inherits its data type from the Field itself. For example, in a Trial Balance Report, which is a drill down report, there is a need to retain the Group Name which has been selected by the user. So, each time the user scrolls up and down, the field value changes and the current field value is passed on to the variable immediately, so that if the current group is selected and drilled down, the report begins with the sub groups and ledgers of the selected group.

Syntax

 [Field : Field Name]

 Variable : Variable Name

Example: [!Field : DSP Group Acc]

    Variable : Group Name

This is used in the ‘List of Accounts’ Report in Tally.ERP 9, wherein the optional Field DSP Group Acc is made to act as a variable by using the Field attribute ‘Variable’, and the value selected by the user is passed on to this variable for further use.

 Modifying the Variable Value

A Field attribute Modifies is used to modify the value of a variable.

Syntax [Field : Field Name]

 Modifies : Variable Name

Example: [Field : SLedger]

 Modifies : SLedger

The SLedger Variable is modified with the value stored/keyed in the Field SLedger.

 Buttons and Keys

The actions in TDL can be delivered in three ways - by activating a Menu Item, by pressing a Key or by activating a Button. The definition of both Buttons and Keys are the same, but at the time of deployment, Keys differ from Buttons. All the Buttons used within the attribute ‘Buttons’ are visible on the button bar, so that the user can either click it or press the unique key combination. All the Buttons used within the attribute ‘Keys’ are invisible entities and the key combination associated in the Key must be pressed to activate a key; whereas to activate a button, either it can be clicked or the key combination assigned for the button can be pressed

Attributes of Buttons/Keys

Title The ‘Title’ attribute can be used to give a meaningful Title to the Button being displayed on the Button Bar. This attribute is optional.

Syntax [Key/Button : Key/Button Name]

Title : Button Title

 Example: [Button : NonColumnar]

Title : “No Columns”

Action The Action attribute is used to associate an Action with the Button. Every Button or Key is defined for the purpose of executing certain predefined actions.

Syntax [Key/Button : Key/Button Name]

 Action : Required Action

 Example: [Button : NonColumnar]

Action : Set : ColumnarDayBook : NOT ##ColumnarDayBook

In case the Title is not specified, then by default, it assumes the Button Name as its title. In cases where it is used as a Key, the Title is ignored, since the Keys are hidden in a Menu or a Report.

Inactive The Inactive attribute is used to activate the Button, based on some condition. If the condition is FALSE, the button will be displayed, but it cannot be activated.

 Syntax [Key/Button : Key/Button Name]

Inactive :

Example: [Button : Close Company]

Inactive : $$SelectedCmps < 1