Add annotations

[BeritJanssen]

Next to tagging documents, it is also conceivable that users may want to annotate them.

[lukavdplas]

Question: making annotation is possible in ontraqh, would it be possible to transfer this to I-analyer? @JeltevanBoheemen @ar-jan

[JeltevanBoheemen]

I would call the Ontraqh implementation rickety at best.
The code for selecting text works fine, can reuse some of it.
The code for rendering annotations (and links between annotations) is a mess of ngZone, setTimeout and events going up and down 4 levels of Input/Output.

So it could be transfered, with a whole lot of refactoring.

[ar-jan]

We also experienced poor rendering performance in some situations which we didn't fully resolve.

[lukavdplas]

Out of curiosity, how did you save annotations in the backend? In the SQL database or elasticsearch?

[ar-jan]

In the SQL database. We did consider ES, but that would've involved working around the lack of standard MySQL features, mainly referential integrity for storing links between annotations, and user account creating the annotation.

[lukavdplas]

For the record: we're currently looking into adding integration with the scholarly web annotation client