OO ALV Quick Reference

An

Easy Reference

for

ALV GRID CONTROL

Serdar SIMSEKLER

2004, Ankara TURKEY

© Copyright 2003 SAP AG. All rights reserved.

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Table of Contents

Purpose..........................................................................................................................1

Prerequisites .................................................................................................................1

A. Introduction .............................................................................................................1

B. Building Blocks ........................................................................................................1

B.1. General Scheme..................................................................................................2

B.2. Building Field Catalog .......................................................................................7

B.2.1. Structure of a Field Catalog ........................................................................7

B.2.2. Building Field Catalog Manually...............................................................9

B.2.3. Building Field Catalog Semi-Automatically............................................10

B.3. Layout Adjustments .........................................................................................12

B.4. Printing Adjustments........................................................................................14

B.5. Excluding Unwanted Standard Function Buttons ............................................15

C. Non-Event Based Additional Functionalities .....................................................16

C.1. Changing Field Catalog or Layout after First Display.....................................16

C.2. Setting Sort Conditions ....................................................................................16

C.3. Filtering ............................................................................................................17

C.4. Making Selections ............................................................................................18

C.5. Retrieving and Setting Scroll Status Info.........................................................19

C.6. Coloring ............................................................................................................19

C.6.1. Coloring an Entire Column .......................................................................20

C.6.2. Coloring an Entire Row.............................................................................20

C.6.3. Coloring Individual Cells ..........................................................................21

C.7. Inserting Hyperlinks .........................................................................................22

C.8. Making Fields as Dropdown Menus ................................................................23

C.9. Managing variants ............................................................................................24

D. Event Based Additional Functionalities ..............................................................25

D.1. General Scheme for the Event Handler Class ..................................................26

D.2. Hotspot Clicking ..............................................................................................28

D.3. Double Clicking ...............................................................................................29

D.4. Pushbuttons On The List..................................................................................29

D.5. Adding Your Own Functions ...........................................................................30

D.6. Overriding Standard Functions ........................................................................32

D.7. Context Menus .................................................................................................32

D.8. About printing..................................................................................................33

D.9. Making ALV Grid Editable .............................................................................34

D.10. Controlling Data Changes ..............................................................................35

D.11. Linking F1 Help to Fields ..............................................................................36

D.12. Linking F4 Help to Fields ..............................................................................37

E. A Piece of Troubleshooting...................................................................................38

TRADEMARKS .......................................................... Error! Bookmark not defined.

Purpose

The purpose of this tutorial is to provide an easy and quick reference that may

be used as a guide while coding to build lists using ALV Grid Control. Actually, there

is easy-to-reach information about implementing ALV Grid lists. However, it is

generally required to find the information sought in a quicker way. This tutorial

handles this, being a condensed source that can be used as a “guide.” It will not deal

with the technical infrastructure on which ALV lays. Some of the tables are taken

from the online SAP Library, which is the most trustable source about the topic.

Shortly, this will be a booklet summarizing major capabilities of the ALV Grid

Control.

To get deep into the ALV Grid control, you can refer to the standard SAP

course “BC412 – ABAP Dialog Programming Using EnjoySAP Controls” and the

book “Controls Technology”. Also you had better inspect demo programs.

Prerequisites

To use ALV Grid Control in a simple manner, it will be sufficient just having

experience on dialog programming. However, to make use of more capabilities, it is

required some knowledge on object-oriented perspective of ABAP programming. A

general knowledge on control framework is supposed to exist.

A. Introduction

Here is the definition for ALV from SAP Help:

“The ALV Grid control is a flexible tool for displaying lists. The tool provides

common list operations as generic functions and can be enhanced by self-defined

options.”

The ALV Grid control is used to build non-hierarchical, interactive, and

modern-design lists. As a control, it is a component that is installed on the local PC.

The ALV Grid control provides typical list functions as sorting, filtering,

summing, etc.,while also gives the opportunity to develop user functions where

needed. It presents numerous interfaces like Excel Inplace and Crystal Reports.

The wrapper class implemented to encapsulate ALV Grid functionality is

“CL_GUI_ALV_GRID”. There is another way to display lists with ALV utilizing

“REUSE_ALV...” functions. However, that way is not comprised in this tutorial.

B. Building Blocks

While preparing a list to be displayed via an ALV grid control, we have some

basic components to prepare. These are;

i. List data: Obviously, this is the data in an internal table to be listed. Standard

ALV functions except sorting makes just read access to the list data.

However, sorting changes state of the internal table. The internal table

holding list data may be of any flat type. Deep types are only allowed

when set for some functionalities of ALV Grid.

ii. Field Catalog: We use another internal table to define specifications on how

the fields of our list will be displayed. This internal table is called the

“field catalog”. The field catalog must comprise some technical and

additional information about display options for each column to be

displayed. There are three procedures to generate the field catalog as

“Automatic generation”, “Semi-automatic generation”, and “Manual

generation”. The internal table for the field catalog must be referenced to

the dictionary type “LVC_T_FCAT”.

iii. Layout Structure: We fill a structure to specify general layout options for the

grid. With this structure we can set general display options, grid

customizing, totals options, color adjustments etc... The layout structure

must be of type “LVC_S_LAYO”.

iv. Event Handler: We should define and implement an event handler class if

we want to handle events triggered by the ALV Grid instance. After

creating ALV Grid instance, we must register an instance of this event

handler class to handle ALV Grid events.

v. Additional Data: To trigger some additional features of ALV Grid we can

have some additional data to pass as parameters. For example, initial

sorting criteria, buttons to be deactivated, etc...

B.1. General Scheme

Now, we can figure out a primitive scheme to prepare our ALV Grid. As a

control object, ALV Grid instance requires a container to be linked to the screen.

Generally, an instance of the class “cl_gui_custom_container” is used for this

purpose. Instances of some other container classes such as

“cl_gui_docking_container”, “cl_gui_dialogbox_container” may also be

used. In our example we take a custom container. To create a custom container

instance, we need a custom control area on the screen.

Step 1 Add a custom control on the screen which will be related to the

custom container. Let’s give it the name ‘CC_ALV’.

Step 2 Declare global variables to be used for ALV Grid.

*-- Global data definitions for ALV

*--- ALV Grid instance reference

DATA gr_alvgrid TYPE REF TO cl_gui_alv_grid .

*--- Name of the custom control added on the screen

DATA gc_custom_control_name TYPE scrfname VALUE ‘CC_ALV’ .

*--- Custom container instance reference

DATA gr_ccontainer TYPE REF TO cl_gui_custom_container .

*--- Field catalog table

DATA gt_fieldcat TYPE lvc_t_fcat .

*--- Layout structure

DATA gs_layout TYPE lvc_s_layo .

Code Part 1 – Global data definitions for ALV

Step 3 Declare your internal table which is supposed to hold the list data.

Let’s name it “gt_list”. Here is an example declaration.