Iterator: Interface IF_HTMLB_TABLEVIEW_ITERATOR (SAP Library

Iterator: Interface IF_HTMLB_TABLEVIEW_ITERATOR

Overview

Definition

The iterator is an instance object that implements the interface IF_TABLEVIEW_ITERATOR. With the iterator, you can create complex logic for <htmlb:tableView> elements, for example for the evaluation of a TableView row and calculation of the value of another row.

This iterator interface makes it possible that a <htmlb:tableView> BSP element is not rendered in one step, but that there is a communication with the application after each field or column which enables the application to influence the rendering of a certain field, row or column.

As <htmlb:tableView> does not contain application logic itself, the iterator allows the TableView to handle data very flexibly.

The interface should be implemented by the corresponding application class of the BSP application, or – when controllers are used – by the controller class.

Process Flow

The interface IF_HTMLB_ITERTATORcontains 3 callback methods.

When processing its BSP (in which its own iterator object is embedded) with <htmlb:tableView iterator="<%= my_iterator %>" ... />, the iterator calls back the three interface methods every time it encounters an <htmlb:tableView/> element or an <htmlb:tableViewColumns/> element.

Use

...

1. In transaction SE24, you can create your own class that implements the interface IF_HTMLB_TABLEVIEW_ITERATOR.

2. Instantiate your iterator class.

Note that you execute the instantiation via the application class or the controller class.

3. Embed your iterator instance in the <htmlb:tableView iterator=<%= my_iterator %> ... /> element.

4. The three methods of IF_HTMLB_TABLEVIEW_ITERATOR are called, i.e., called back. You can implement them according to your needs.

Background documentation

Minimal example coding for the implementation of the method render_cell_start:

method if_htmlb_tableview_iterator~render_cell_start.

* html_bee object is responsible to modify HTML code
  data: html_bee type ref to cl_bsp_bee_html.
  data: col_value type string.
  data: html_str type string.

* <row> is a structure of table

field-symbols: <row> type any, <col> type any.

* p_column_key has a name of each table column
if p_column_key = 'COLUMN_NAME'.

*   conventional logic to extract column value
    assign p_row_data_ref->* to <row>.
    assign component p_column_key of structure <row> to <col>.
     col_value = <col>.
    create object html_bee.
    if col_value = 'CONDITION_YOU_WANT'.

* do something interesting

html_str = "<HTML_code_you_want_to_generate_dynamically />"
endif.

*   set HTML code you want...add() can have up to 10 params for concatenation
    html_bee->add( html = html_str ).
    p_replacement_bee = html_bee.

endif.

endmethod.

Inheritance Hierarchy/Interface Composition

Implementing Classes

Enhanced Interface

Specialized Interfaces

Attributes

Methods

Method get_column_definitions

Signature
Description	This method is called at the start of the rendering of the TableViews. This methode contains important import parameters which provide information about the current TableView. The row definitions of the TableViews are handed over. At this moment, the application can exert influence. Overwrite this methode, if you plan to make changes here.
Parameters	P_TABLEVIEW_ID	Import parameter for the ID
	P_COLUMN_DEFINITIONS	Changing parameter for columns in the TableView
	P_OVERWRITES	Changing parameter to overwrite certain cells in the TableView
Return values / Exceptions	-

Method render_row_start

Signature
Description	RENDER_ROW_START is called at the beginning of every row. This methode contains important import parameters which provide useful information about the current row. Use this method if you want to influence the rendering at the beginning of every row. You can filter rows or insert additional information to the rendering. This is especially convenient for tables that do not put out all rows. You can give the rendering information exactly to the rows that are rendered.
Parameters	P_TABLEVIEW_ID	Import parameter for the ID
	P_ROW_INDEX	Import parameter for the row index
	P_ROW_KEY	Import parameter for the row key
	P_ROW_DATA_REF	Import parameter for the reference to the data of a row
	P_EDIT_MODE	Import parameter for a checkbox
Return values / Exceptions	P_SKIP_ROW	checkbox

Method render_cell_start

Signature
Description	RENDER_CELL_START is called at the beginning of every column (cell), i.e., before the rendering of every single table field. You use this method to render columns dynamically. Via the import parameters, you obtain the row and column index, as well as a reference to the current row. Thus, you can define a custom rendering for a certain row as is shown in: Custom-Rendering for the Author column. To define a new rendering engine, use the parameter p_replacement_bee. Then, the <htmlb:tableView> element calls this application-specific renderer for this row.
Parameters	P_TABLEVIEW_ID	Import parameter for the ID
	P_CELL_ID	Import parameter for the cell ID
	P_CELL_BINDING	Importparameter for the binding name
	P_ROW_INDEX	Import parameter for the row index
	P_ROW_KEY	Import parameter for the row key
	P_COLUMN_INDEX	Import parameter for the column index
	P_COLUMN_KEY	Import parameter for the column key
	P_ROW_DATA_REF	Import parameter for the reference to the data of a row
	P_EDIT_MODE	Import parameter for a checkbox
	P_REPLACEMENT_BEE	Export parameter for a BSP extension expression (BEE)
	P_STYLE	Changing parameter for <td style="...">. When using Design2003, you can change the background color of a cell with predefined colors via P_STYLE (P_CLASS is no longer analyzed in Design2003). To do this, use the attribute cellDesign in P_STYLE (e.g. P_STYLE="cellDesign:STCD_STANDARD"). Possible values of cellDesign are STCD_STANDARD, STCD_ALTERNATING, STCD_TRANSPARENT, STCD_NEGATIVE, STCD_POSITIVE, STCD_TOTAL, STCD_SUBTOTAL, STCD_SUBTOTAL_LIGHT, STCD_BADVALUE_DARK, STCD_BADVALUE_MEDIUM, STCD_BADVALUE_LIGHT, STCD_CRITICALVALUE_DARK, STCD_CRITICALVALUE_MEDIUM, STCD_CRITICALVALUE_LIGHT, STCD_GOODVALUE_DARK, STCD_GOODVALUE_MEDIUM, STCD_GOODVALUE_LIGHT, STCD_GROUP_HIGHLIGHTED, STCD_GROUP_HIGHLIGHTED_LIGHT, STCD_KEY_MEDIUM, STCD_GROUP_LEVEL1, STCD_GROUP_LEVEL2, STCD_GROUP_LEVEL3, STCD_MARKED, STCD_FILTER and STCD_POPIN. You can find an example for the use of cellDesign in the BSP application sbspext_table, page TableViewIterator.bsp, iterator class CL_SBSPEXT_ITERATOR, method IF_HTMLB_TABLEVIEW_ITERATOR~RENDER_CELL_START, row 50: if design eq '2002'. p_style = 'background-color:#BBDDDD'. elseif design eq '2003'. p_style = 'celldesign:GROUP_HIGHLIGHTED_LIGHT'. endif. Note, that the specification of cellDesign does not have any effect in Design2002. If you want to change the background color there, you have to do this via CSS attributes. On the other hand, it is no longer possible to set specifications in Design2003 style for the cell, except via cellDesign itself.
	P_CLASS	Changing parameter for <td class="...">. Note, that P_CLASS is no longer anaylzed in Design2003.
	P_ISREADONLY	Changing parameter for <td readonly>.
Return values / Exceptions	-

Example

You find an example in the BSP tutorial: Our Little Online Bookshop using MVC and HTMLB and Custom-Rendering for the Author column.