Computer systems can process text and user interface elements left to right (as is the case in English) or right to left. Software that has support to handle these languages are said to have bi-di support.
Because existing 5250 applications are often already bi-di enabled, converting these applications requires some special steps to ensure that the WebFacing process interprets the direction of the input screens correctly.
Web technology like HTML and XHTML support bi-di with the common base direction attribute dir which can have a value of ltr (left-to-right) or rtl (right-to-left). This attribute can be applied to a number of different tags and the effect depends on the type of widget. Child elements inherit from the parent element. For example, to set the base direction of the entire HTML document to right-to-left, you would apply the attribute to the <html> tag: <html dir="rtl">.
Tabbable widgets (elements that should be accessible by using the Tab key like fields and hyperlinks) can be assigned a tab index. Most browsers assume a default tab index order that proceeds through all tabbable widgets from left-to-right and top-to-bottom.
On 5250 screens where the CHECK(RLTB) keyword is used, WebFacing assigns a tabindex to correctly implement right-to-left tabbing order within the left-to-right HTML page. These tabindices are assigned based on the DDS row and column position. To leave room for moving fields outside of their DDS positions that are constrained to 27 rows and 132 columns at most, WebFacing uses a grid that has 132 rows and 250 columns. (The maximum value for the tabindex attribute is 32767.)
In the case of new tabbable widgets added through Web settings, you can use the substitution variable &{TABINDEX}. This will calculate the correct tab index order of your widget at conversion time.
\ { } [ ]Therefore, the tab index substitution variable is not supported for members using the Arabic 420 code page, nor are other Javascript constructs, like arrays, that rely on these characters.
In addition, Arabic becomes unshaped because it is stored in logical format in the member which is visual format.