Changes between Initial Version and Version 1 of MapGuideRfc176

Timestamp:

Aug 5, 2019, 9:46:49 AM (5 years ago)

Author:

jng

Comment:

--

MapGuideRfc176

@@ +1 @@
+
+= !MapGuide RFC 176 - Update QUERYMAPFEATURES to include selection key with feature attributes =
+
+This page contains a change request (RFC) for the !MapGuide Open Source project.
+More !MapGuide RFCs can be found on the [wiki:MapGuideRfcs RFCs] page.
+
+== Status ==
+
+||RFC Template Version||(1.0)||
+||Submission Date||6 Aug 2019||
+||Last Modified||6 Aug 2019||
+||Author||Jackie Ng||
+||RFC Status||ready for review||
+||Implementation Status||pending||
+||Proposed Milestone||3.0||
+||Assigned PSC guide(s)||(when determined)||
+||'''Voting History'''||(vote date)||
+||+1||||
+||+0||||
+||-0||||
+||-1||||
+||no vote|| ||
+
+== Overview ==
+
+This RFC proposes to introduce a new version of `QUERYMAPFEATURES` that includes selection key with feature attributes.
+
+== Motivation ==
+
+The current `QUERYMAPFEATURES` (v2.6.0) operation allows requesting an XML selection set along with feature attributes for this selection.
+
+The layout of this response is such that one might think that would be possible to implement viewer features like sub-selection highlighting by using the array index of the feature attributes collection to pick the corresponding selection key from the selection set XML.
+
+It turns out that, this approach is based on a fatally-flawed assumption that selection set XML is rendered out in the same order as the selected feature attributes. This is actually not the case.
+
+The result of this incorrect assumption results in bugs such as this one for [https://github.com/jumpinjackie/mapguide-react-layout/issues/804 mapguide-react-layout] where wrong features are being sub-selected with respect to the "current" feature's attributes being displayed on the property palette.
+
+== Proposed Solution ==
+
+Introduce a new `QUERYMAPFEATURES` v4.0.0 operation.
+
+This takes the same parameters as its v2.6.0 counterpart, except when requesting feature attributes, the operation will include a `<SelectionKey>` element along side every `<Feature>` element in the selection attribute set.
+
+This selection key can be used to construct a new selection XML by which a proper sub-selection highlighting can be done.
+
+Instead of trying to pick the matching selection key by (erroneous) array index lookup in the selection set XML, the selection key is included with every feature's attributes.
+
+== Implications ==
+
+This is a new operation.
+
+== Test Plan ==
+
+Verify proper sub-selection is possible with v4.0.0 `QUERYMAPFEATURES`
+
+== Funding / Resources ==
+
+Community