[SIS-163] Unsupported WKT 2 features

• Type: Task
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 0.4, 0.5, 0.6
• Component/s: Referencing
• Assignee: Unassigned
• Reporter: Martin Desruisseaux
• Created: 04/Feb/14 15:08
• Updated: 25/Feb/16 13:00

Description

This page summarizes the WKT 2 features which are currently not supported in Apache SIS. More details are provided in the sub-tasks for unsupported elements and restrictions. The third sections is about recommendations that are not mandatory, but that we do not yet follow.

Unsupported WKT elements

• ParametricCRS (we need an implementation in the rest of SIS first).
• Bearing element for polar coordinate systems having a "clockwise" or "counterClockwise" axis direction.
• BoundCRS element as the successor of the WKT 1 TOWGS84 element.
• Time extent with named eras (e.g.TIMEEXTENT["Jurassic", "Quaternary"])

Restrictions that we do not verify

• ISO 19162 restrictions on CompoundCRS: (geographic or projected or engineering) followed by (vertical or parametric) followed by temporal. (edit: fixed)
• ISO 19162 restrictions on axis name, abbreviation and directions (e.g. geographic CRS shall be ‘latitude’, ‘longitude’).
• Precedence of EPSG codes over names for Conversion objects.

Recommendations that we do not yet follow

• Formatter should be able to write the short WKT 2 keywords (currently we format only the long ones, because they match the type names). (edit: fixed)
• We do not check the recommended maximum string lengths (80 characters in names, 255 characters in other quoted texts, 4096 in total).

Issue Links

• is related to: SIS-10 Ability to create SIS data from WKT specs
• relates to: SIS-175 Omitted ISO 19109 attributes

Sub-Tasks

• Support explicit Order element in axes: Closed
• Support Bearing element in axes: Open
• Support BoundCRS element: Open
• Support parsing and formatting of ParametricCRS: Closed
• Parse and format TimeExtent with named eras: Open
• Enforce character encoding restriction at format time: Closed
• Verify axis name, abbreviation and direction constraints at format time: Open
• Verify CompoundCRS restrictions at format time: Closed
• Enforce precedence of EPSG codes over names at parsing time: Open