Support of base text direction for Bootstrap v4 JS widgets

Created by: ashensis

The important requirement to any program product from the Arabic/Hebrew customer's perspective is support for base text direction. For detailed explanation of what base text direction term means please see, for instance, pages 5-9 of the following reference document.

​https://docs.google.com/document/d/1dDrSwimrQbpbXybhMYDEiJXLeeqvelnY4cc8HeCP1Nk/edit?usp=sharing

Every platform (like MS Office or Open Office) or web based (like CKEditor, IBM Docs) text editor as well as large variety of program products and platforms (like dojo) allows the possibility to specify the base text direction that impacts the display of Arabic/Hebrew text. The current proposal is to introduce the base text direction into Bootstrap JS widgets. Possible candidates for support are Popover and Tooltip (these widgets create their HTML markup dynamically).

How to specify 'base text direction' for bootstrap widgets Bootstrap widgets would provide BTD basing on 'textdir' option been passed to widget constructor. Alternatively BTD may be specified decoratively as 'data-textdir' attribute of corresponding html element.

Allowed values are: "ltr" (left-to-right), "rtl" (right-to-left) and "contextual" (meaning that either 'ltr' or 'rtl' value is used depending on the first strong(Arabic/Hebrew or English) character of string been displayed.