ReCoding using Template Method Design Pattern

• Download TemplateMethodDesignPattern.zip - 8.0 KB

Introduction

I recently recognized the importance of design pattern so that started to change non-design-pattern-code to design-pattern-code in my project. In this part I introduce my example that adaptes Template Method Design Pattern but I don't know whether this is good or bad. I wish to listen your opinion honestly.

Background

Template Method Design Pattern defines the program skeleton of an algorithm on Template Method of abstract class. Child classe instantiates this algorithm by implementing their own logics on the skeleton that is abstract method provided by abstract class.

Coding without considering Design Pattern

Fuction InitCommonVariables() initializes two ArrayLists using filtering from datatable(dtMSTDLDTM) and repeats this work for other datatable(dtMEVENT). We can figure out two initialization processes have same algorithm.

       /// Initialize Current Activity        

        private void InitCommonVariables()
        {
            // Get Selected Activity

            currentActivity = (Progress.Model.ProgressActivity)this.Activity;
            if (currentActivity.BNodeLevel == (int)ActivityNodeLevel.Kojun)
            {
                // Ready to Set ComboBox Items from M_STDLDTM DataTable

                dtMSTDLDTM = ((ProgressGanttModel)(currentActivity.GanttModel)).dtMSTDLDTM;
                if (dtMSTDLDTM.Rows.Count > 0)
                {
                    // Set Primary Key of Table for Row Search

                    System.Data.DataColumn[] primaryKey = new System.Data.DataColumn[1];
                    primaryKey[0] = dtMSTDLDTM.Columns[0];
                    dtMSTDLDTM.PrimaryKey = primaryKey;
                    listWrkID = new ArrayList();
                    listWrkNM = new ArrayList();
                    // Set Filter

                    String filter = "";
                    if (initParams.scheduleType == EnumScheduleType.Mschedule)
                    {
                      filter = "SCH_TYP<>2";
                    }
                    else if (initParams.scheduleType == EnumScheduleType.Sschedule)
                    {
                      filter = "SCH_TYP=2";
                    }
                    filter = "(" + filter + ") AND (DEL_FLG<>1)";
                    // Initialize ArrayList

                    foreach (System.Data.DataRow row in dtMSTDLDTM.Select(filter))
                    {
                        listWrkID.Add(row["WRK_ID"].ToString());
                        listWrkNM.Add(row["WRK_NM"].ToString());
                    }
                }
                // If DataTable has no Column Add Columns for Error Handling

                if (dtMSTDLDTM.Columns.Count == 0)
                {
                    System.Data.DataColumn wrkIDColumn = new System.Data.DataColumn("WRK_ID");
                    System.Data.DataColumn wrkNMColumn = new System.Data.DataColumn("WRK_NM");
                    dtMSTDLDTM.Columns.Add(wrkIDColumn);
                    dtMSTDLDTM.Columns.Add(wrkNMColumn);
                }
                // Ready to Set ComboBox Items from M_EVENT DataTable

                if (currentActivity.BEventFlg == 1)
                {
                    dtMEVENT = ((ProgressGanttModel)(currentActivity.GanttModel)).dtMEVENT;
                    if (dtMEVENT.Rows.Count > 0)
                    {
                        // Set Primary Key of Table for Row Search

                        primaryKey = new System.Data.DataColumn[1];
                        primaryKey[0] = dtMEVENT.Columns[0];
                        dtMEVENT.PrimaryKey = primaryKey;
                        listEventID = new ArrayList();
                        listEventNM = new ArrayList();
                        // Initialize ArrayList

                        foreach (System.Data.DataRow row in dtMEVENT.Rows)
                        {
                            listEventID.Add(row["EVENT_ID"].ToString());
                            listEventNM.Add(row["EVENT_NM"].ToString());
                        }
                    }
                    // If DataTable has no Column Add Columns for Error Handling

                    if (dtMEVENT.Columns.Count == 0)
                    {
                        System.Data.DataColumn eventIDColumn = new System.Data.DataColumn("EVENT_ID");
                        System.Data.DataColumn eventNMColumn = new System.Data.DataColumn("EVENT_NM");
                        dtMEVENT.Columns.Add(eventIDColumn);
                        dtMEVENT.Columns.Add(eventNMColumn);
                    }
                }
            }
      } 

Using two ArrayList, I initialized a ComboBox.

        /// Set Work Name On KojunNameComboBox

        private void SetItemsonKojunNameCombo(ComboBox comboBox, System.Data.DataTable dataSource)
        {
            comboBox.DisplayMember = "WRK_NM";
            comboBox.ValueMember = "WRK_ID";
            System.Data.DataTable dataTable = getMStdLdTmFilterTbl(dataSource);
            // Set Value from DataTable

            comboBox.DataSource = dataTable;
            if (dataTable.Rows.Count > 0)
            {
                // Add Current Activty Item if not in M_STDLDTM Table

                int currentItemIndex = listWrkID.IndexOf(currentActivity.BWrkId);
                if (currentItemIndex >= 0)
                {
                    // Change Work Name

                    System.Data.DataTable displayTable = dataTable.Copy();
                    displayTable.Rows[currentItemIndex]["WRK_NM"] = currentActivity.Name;
                    comboBox.DataSource = displayTable;
                    comboBox.SelectedIndex = currentItemIndex;
                }
                else
                {
                    System.Data.DataTable displayTable = dataTable.Copy();
                    System.Data.DataRow row = displayTable.NewRow();
                    if (currentActivity.BWrkId != null)
                    {
                        row["WRK_ID"] = currentActivity.BWrkId;
                    }
                    else
                    {
                        row["WRK_ID"] = -1;
                    }
                    if (currentActivity.BWrkName != null)
                    {
                        row["WRK_NM"] = currentActivity.BWrkName;
                    }
                    else
                    {
                        // Set Empty

                        row["WRK_NM"] = "";
                    }
                    displayTable.Rows.InsertAt(row, 0);
                    comboBox.DataSource = displayTable;
                    comboBox.SelectedIndex = 0;
                }
            }
            else
            {
                System.Data.DataTable displayTable = dataTable.Copy();
                displayTable.Clear();
                if (currentActivity.BWrkId != null)
                {
                    System.Data.DataRow row = displayTable.NewRow();
                    row["WRK_ID"] = currentActivity.BWrkId;
                    row["WRK_NM"] = currentActivity.BWrkName;
                    displayTable.Rows.Add(row);
                }
                comboBox.DataSource = displayTable;
                if (currentActivity.BWrkId != null)
                {
                    comboBox.SelectedIndex = 0;
                }
            }
        }        
        /// Set Event Name On EventNameComboBox

        private void SetItemsonEventNameCombo(ComboBox comboBox, System.Data.DataTable dataSource)
        {
            comboBox.DisplayMember = "EVENT_NM";
            comboBox.ValueMember = "EVENT_ID";
            // Set Value from DataTable

            comboBox.DataSource = dataSource;
            if (dataSource.Rows.Count > 0)
            {
                // Add Current Event Item if not in M_EVENT Table

                int currentItemIndex = -1;
                if (currentActivity.Name != null)
                {
                    currentItemIndex = listEventNM.IndexOf(currentActivity.Name);
                }
                if (currentItemIndex >= 0)
                {
                    // Show Current Tree's Event Name if Tree has a same EventID

                    System.Data.DataTable displayTable = dataSource.Copy();
                    //displayTable.Rows[currentItemIndex]["EVENT_NM"] = currentActivity.Name;

                    comboBox.DataSource = displayTable;
                    comboBox.SelectedIndex = currentItemIndex;
                }
            }
            // Set Event Items ReadOnly

            comboBox.DropDownStyle = ComboBoxStyle.DropDownList;
        }

Lastly, I saved the selected item and selected value from ComboBox

        private void SaveKojunWorkNMandID()
        {
            // T_SCH_WRK's WRK_NM

            currentActivity.BWrkName = kojunNameCombo.Text;
            // T_SCH_TREE's WRK_NM

            currentActivity.Name = kojunNameCombo.Text;
            
            // T_SCH_WRK's WRK_ID

            if (listWrkID.Contains(kojunNameCombo.SelectedValue))
            {
                int selectedIndex = listWrkID.IndexOf(kojunNameCombo.SelectedValue);
                if (selectedIndex >= 0)
                {
                    // If not Changed

                    if (kojunNameCombo.Text == (string)listWrkNM[selectedIndex])
                    {
                        currentActivity.BWrkId = (string)kojunNameCombo.SelectedValue;
                    }
                    else
                    {
                        currentActivity.BWrkId = "";
                    }
                }
                else
                {
                    currentActivity.BWrkId = "";
                }
            }
            else
            {
                currentActivity.BWrkId = "";
            }
        }
        private void SetEventNMandID()
        {
            // T_SCH_WRK's WRK_NM

            currentActivity.BWrkName = eventNameCombo.Text;
            // T_SCH_TREE's WRK_NM

            currentActivity.Name = eventNameCombo.Text;
            // T_SCH_WRK's WRK_ID

            if ((eventNameCombo.SelectedIndex >= 0) && (eventNameCombo.SelectedIndex < listEventID.Count))
            {
                currentActivity.BWrkId = (string)listEventID[eventNameCombo.SelectedIndex];
            }
        }

ReCoding using Design Pattern

I designed two template methods: InitializeList() and InitializeItemsOnComboBox() and two child class: ConcreteTableToKojunComboBox and ConcreteTableToEventComboBox.

    class PADUtil
    {
        public abstract class AbstractTableToComboBox
        {
            public abstract void CreateList();
            public abstract bool CheckTable();
            public abstract bool HasColumnsandRows();
            public abstract void SetFilter();
            public void InitializeList()
            {
                SetFilter();
                if (CheckTable() && HasColumnsandRows())
                {
                    CreateList();
                }
            }
            public abstract void SetComboBoxMember();
            public abstract int HasCurrentItem();
            public abstract void JustSetCurrentItem(int index);
            public abstract void AddandSetCurrentItem();
            public void InitializeItemsOnComboBox()
            {
                SetComboBoxMember();
                int index = HasCurrentItem();
                if (index >= 0)
                {
                    JustSetCurrentItem(index);
                }
                else
                {
                    AddandSetCurrentItem();
                }
            }
            public abstract object GetValueOfCurrentItem(object dispaly);
        }
        public class ConcreteTableToKojunComboBox : AbstractTableToComboBox
        {
            private DataTable table;
            private ArrayList displayList;
            private ArrayList valueList;
            private string filter = "";
            private string displayMember = "";
            private string valueMember = "";
            private EnumScheduleType scheduleType;
            private ComboBox comboBox;
            public struct CurrentItem
            {
                public object display;
                public object value;
            }
            public CurrentItem currentItem = new CurrentItem();
            public ConcreteTableToKojunComboBox(DataTable table, ArrayList displayList, ArrayList valueList, DataColumn[] primaryKey, string displayMember, string valueMember, EnumScheduleType scheduleType, ComboBox comboBox)
            {
                this.table = table;
                this.displayList = displayList;
                this.valueList = valueList;
                this.table.PrimaryKey = primaryKey;
                this.displayMember = displayMember;
                this.valueMember = valueMember;
                this.scheduleType = scheduleType;
                this.comboBox = comboBox;
            }
            public override bool CheckTable()
            {
                if (table == null || displayList == null || valueList == null || displayMember == "" || valueMember == "")
                {
                    return false;
                }
                return true;
            }
            public override bool HasColumnsandRows()
            {
                if (table.Columns.Count == 0)
                {
                    table.Columns.Add(new DataColumn(displayMember));
                    table.Columns.Add(new DataColumn(valueMember));
                    return false;
                }
                else if (table.Rows.Count == 0)
                {
                    return false;
                }
                return true;
            }
            public override void SetFilter()
            {
                if (table.Columns.Contains("SCH_TYP") && table.Columns.Contains("DEL_FLG"))
                {
                    if (scheduleType == EnumScheduleType.Mschedule)
                    {
                        filter = "SCH_TYP<>2";
                    }
                    else if (scheduleType == EnumScheduleType.Sschedule)
                    {
                        filter = "SCH_TYP=2";
                    }
                    filter = "(" + filter + ") AND (DEL_FLG<>1)";
                }                
            }
            public override void CreateList()
            {
                foreach (System.Data.DataRow row in table.Select(filter))
                {
                    displayList.Add(row[displayMember].ToString());
                    valueList.Add(row[valueMember].ToString());
                }
            }
            public override void SetComboBoxMember()
            {
                this.comboBox.DisplayMember = this.displayMember;
                this.comboBox.ValueMember = this.valueMember;
            } 
            public override int HasCurrentItem()
            {
                if((currentItem.value == null))
                {
                    return -1;
                }
                int index = -1;
                foreach (System.Data.DataRow row in table.Select(filter))
                {
                    index++;
                    if (row[valueMember].ToString() == currentItem.value.ToString())
                    {
                        return index;
                    }
                }
                return -1;
            }
            private DataTable MakeComboBoxDataSource()
            {
                DataTable displayTable = table.Copy();
                displayTable.Clear();
                foreach (DataRow row in table.Select(filter))
                {
                    DataRow newRow = displayTable.NewRow();
                    foreach (DataColumn col in table.Columns)
                    {
                        newRow[col.ColumnName] = row[col.ColumnName];
                    }
                    displayTable.Rows.Add(newRow);
                }
                return displayTable;
            }
            public override void AddandSetCurrentItem()
            {
                DataTable displayTable = MakeComboBoxDataSource();
                System.Data.DataRow currentItemRow = displayTable.NewRow();
                currentItemRow[displayMember] = currentItem.display;
                if (currentItem.value != null)
                {
                    currentItemRow[valueMember] = currentItem.value;
                }
                else
                {
                    currentItemRow[valueMember] = "";
                }
                displayTable.Rows.Add(currentItemRow);
                comboBox.DataSource = displayTable;
                if (comboBox.Items.Count > 0)
                {
                    comboBox.SelectedIndex = comboBox.Items.Count - 1;
                }
            }
            public override void JustSetCurrentItem(int index)
            {
                DataTable displayTable = MakeComboBoxDataSource();
                displayTable.Rows[index][displayMember] = currentItem.display;
                comboBox.DataSource = displayTable;
                if ((comboBox.Items.Count > 0) && (index >= 0) && (index < comboBox.Items.Count))
                {
                    comboBox.SelectedIndex = index;
                }
            }
            public override object GetValueOfCurrentItem(object dispaly)
            {
                currentItem.display = dispaly;
                foreach (DataRow row in table.Select(filter))
                {
                    if (row[displayMember] == dispaly)
                    {
                        currentItem.value = row[valueMember];
                        return currentItem.value;
                    }
                }
                currentItem.value = "";
                return currentItem.value;
            }
        }
        public class ConcreteTableToEventComboBox : AbstractTableToComboBox
        {
            private DataTable table;
            private ArrayList displayList;
            private ArrayList valueList;
            private string filter = "";
            private string displayMember = "";
            private string valueMember = "";
            private EnumScheduleType scheduleType;
            private ComboBox comboBox;
            public struct CurrentItem
            {
                public object display;
                public object value;
            }
            public CurrentItem currentItem = new CurrentItem();
            public ConcreteTableToEventComboBox(DataTable table, ArrayList displayList, ArrayList valueList, DataColumn[] primaryKey, string displayMember, string valueMember, EnumScheduleType scheduleType, ComboBox comboBox)
            {
                this.table = table;
                this.displayList = displayList;
                this.valueList = valueList;
                this.table.PrimaryKey = primaryKey;
                this.displayMember = displayMember;
                this.valueMember = valueMember;
                this.scheduleType = scheduleType;
                this.comboBox = comboBox;
            }
            public override bool CheckTable()
            {
                if (table == null || displayList == null || valueList == null || displayMember == "" || valueMember == "")
                {
                    return false;
                }
                return true;
            }
            public override bool HasColumnsandRows()
            {
                if (table.Columns.Count == 0)
                {
                    table.Columns.Add(new DataColumn(displayMember));
                    table.Columns.Add(new DataColumn(valueMember));
                    return false;
                }
                else if (table.Rows.Count == 0)
                {
                    return false;
                }
                return true;
            }
            public override void SetFilter()
            {
                // Need not Filter

            }
            public override void CreateList()
            {
                foreach (System.Data.DataRow row in table.Select(filter))
                {
                    displayList.Add(row[displayMember].ToString());
                    valueList.Add(row[valueMember].ToString());
                }
            }
            public override void SetComboBoxMember()
            {
                this.comboBox.DisplayMember = this.displayMember;
                this.comboBox.ValueMember = this.valueMember;
            }
            public override int HasCurrentItem()
            {
                if ((currentItem.value == null))
                {
                    return -1;
                }
                int index = -1;
                foreach (System.Data.DataRow row in table.Select(filter))
                {
                    index++;
                    if (row[valueMember].ToString() == currentItem.value.ToString())
                    {
                        return index;
                    }
                }
                return -1;
            }
            private DataTable MakeComboBoxDataSource()
            {
                DataTable displayTable = table.Copy();
                displayTable.Clear();
                foreach (DataRow row in table.Select(filter))
                {
                    DataRow newRow = displayTable.NewRow();
                    foreach (DataColumn col in table.Columns)
                    {
                        newRow[col.ColumnName] = row[col.ColumnName];
                    }
                    displayTable.Rows.Add(newRow);
                }
                return displayTable;
            }
            public override void AddandSetCurrentItem()
            {
                DataTable displayTable = MakeComboBoxDataSource();
                System.Data.DataRow currentItemRow = displayTable.NewRow();
                currentItemRow[displayMember] = currentItem.display;
                if (currentItem.value != null)
                {
                    currentItemRow[valueMember] = currentItem.value;
                }
                else
                {
                    currentItemRow[valueMember] = -1;
                }
                displayTable.Rows.Add(currentItemRow);
                comboBox.DataSource = displayTable;
                if (comboBox.Items.Count > 0)
                {
                    comboBox.SelectedIndex = comboBox.Items.Count - 1;
                }
                // Set Items ReadOnly

                comboBox.DropDownStyle = ComboBoxStyle.DropDownList;
            }
            public override void JustSetCurrentItem(int index)
            {
                DataTable displayTable = MakeComboBoxDataSource();
                //displayTable.Rows[index][displayMember] = currentItem.display;

                comboBox.DataSource = displayTable;
                if ((comboBox.Items.Count > 0) && (index >= 0) && (index < comboBox.Items.Count))
                {
                    comboBox.SelectedIndex = index;
                }
                // Set Items ReadOnly

                comboBox.DropDownStyle = ComboBoxStyle.DropDownList;
            }
            public override object GetValueOfCurrentItem(object dispaly)
            {
                currentItem.display = dispaly;
                foreach (DataRow row in table.Select(filter))
                {
                    if (row[displayMember] == dispaly)
                    {
                        currentItem.value = row[valueMember];
                        return currentItem.value;
                    }
                }
                currentItem.value = "";
                return currentItem.value;
            }
        }
    } 
        
        PADUtil.AbstractTableToComboBox MStdLdtmToKojunComboBox;
        PADUtil.ConcreteTableToEventComboBox MEventToEventComboBox;
        /// Initialize Current Activity        

        private void InitCommonVariables()
        {
            // Get Selected Activity

            currentActivity = (Progress.Model.ProgressActivity)this.Activity;
            if (currentActivity.BNodeLevel == (int)ActivityNodeLevel.Kojun)
            {
                // Ready to Set ComboBox Items from M_STDLDTM DataTable

                dtMSTDLDTM = ((ProgressGanttModel)(currentActivity.GanttModel)).dtMSTDLDTM;
                listWrkID = new ArrayList();
                listWrkNM = new ArrayList();
                System.Data.DataColumn[] primaryKey = new System.Data.DataColumn[1];
                primaryKey[0] = dtMSTDLDTM.Columns[0];
                string displayMember = "WRK_NM";
                string vlaueMember = "WRK_ID";
                MStdLdtmToKojunComboBox = new PADUtil.ConcreteTableToKojunComboBox(dtMSTDLDTM, listWrkNM, listWrkID, primaryKey, displayMember, vlaueMember, initParams.scheduleType, kojunNameCombo);
                MStdLdtmToKojunComboBox.InitializeList();
                // Ready to Set ComboBox Items from M_EVENT DataTable

                if (currentActivity.BEventFlg == 1)
                {
                    dtMEVENT = ((ProgressGanttModel)(currentActivity.GanttModel)).dtMEVENT;
                    listEventID = new ArrayList();
                    listEventNM = new ArrayList();
                    primaryKey = new System.Data.DataColumn[1];
                    primaryKey[0] = dtMEVENT.Columns[0];
                    displayMember = "EVENT_NM";
                    vlaueMember = "EVENT_ID";
                    MEventToEventComboBox = new PADUtil.ConcreteTableToEventComboBox(dtMEVENT, listEventNM, listEventID, primaryKey, displayMember, vlaueMember, initParams.scheduleType, eventNameCombo);
                    MEventToEventComboBox.InitializeList();
            }
            }
      }
        /// Set Work Name On KojunNameComboBox

        private void SetItemsonKojunNameCombo()
        {
            ((PADUtil.ConcreteTableToKojunComboBox)MStdLdtmToKojunComboBox).currentItem.display = currentActivity.BWrkName;
            ((PADUtil.ConcreteTableToKojunComboBox)MStdLdtmToKojunComboBox).currentItem.value = currentActivity.BWrkId;
            MStdLdtmToKojunComboBox.InitializeItemsOnComboBox();
        } 
        /// Set Event Name On EventNameComboBox

        private void SetItemsonEventNameCombo()
        {
            ((PADUtil.ConcreteTableToEventComboBox)MEventToEventComboBox).currentItem.display = currentActivity.BWrkName;
            ((PADUtil.ConcreteTableToEventComboBox)MEventToEventComboBox).currentItem.value = currentActivity.BWrkId;
            MEventToEventComboBox.InitializeItemsOnComboBox();
        }
        private void SaveKojunWorkNMandID()
        {
            // T_SCH_WRK's WRK_NM

            currentActivity.BWrkName = kojunNameCombo.Text;
            // T_SCH_TREE's WRK_NM

            currentActivity.Name = kojunNameCombo.Text;            
            string value = (string)((PADUtil.ConcreteTableToKojunComboBox)MStdLdtmToKojunComboBox).GetValueOfCurrentItem(kojunNameCombo.Text);
            currentActivity.BWrkId = value;
        }
        private void SaveEventNMandID()
        {
            // T_SCH_WRK's WRK_NM

            currentActivity.BWrkName = eventNameCombo.Text;
            // T_SCH_TREE's WRK_NM

            currentActivity.Name = eventNameCombo.Text;
            // T_SCH_WRK's WRK_ID

            string value = (string)((PADUtil.ConcreteTableToEventComboBox)MEventToEventComboBox).GetValueOfCurrentItem(eventNameCombo.Text);
            currentActivity.BWrkId = value;
        }

I'm thinking......