[annotator-dev] Anchoring tolerance to annotated content edits

[Cloutier, Philippe (DGARI-Consultant)]

Hi,
Tiki Wiki CMS Groupware has an experimental integration of annotator.js which I am testing. The basics are working. The big problem is we're annotating wiki pages which frequently change, so anchoring robustness needs to be reasonably good.

Apparently, after a change, annotations are not displayed somewhere they should not, which is great. Unfortunately, after a change, there is a high risk that an annotation "disappears" (stops being displayed). Annotator's anchoring strategy seems to be to record start and end offsets on the annotated text's containing elements and to record the annotated text. If the annotated text changes its position in its containing element or if the containing element's path changes, the annotation stops displaying. Which means that several common changes have a nearly 50% chance of breaking anchoring:
1. Fixing a typo in the annotated text's parent elements.
2. Adding, removing or moving a sibling (such as a paragraph) of the parent elements.

Am I missing a document on Annotator's anchoring robustness acknowledging this situation and/or suggesting ways to increase tolerance to modifications of the annotated content?

Philippe Cloutier
Développeur/configurateur Tiki
Service des systèmes d'information du Registre foncier 
Direction des systèmes d'information 
Direction générale adjointe des ressources informationnelles 
Ministère de l'Énergie et des Ressources naturelles
Ministère des Forêts, de la Faune et des Parcs
mern.gouv.qc.ca
mffp.gouv.qc.ca