v2 to v3 state converter

[ailon]

marker.js 3 includes some 180° changes, particularly in the text-based marker realm (Text, Callout, Caption, etc.) This makes backward compatibility for state challenging. Having said that, there's a non-zero chance of making v2 annotations load (or convert) to v3 compatible state. However, given the challenges, I decided to postpone working on this until I can gauge the demand.

If you really care about upgrading an existing project from marker.js 2 to 3 but need to be able to open the old states you have saved, please comment, and provide some context, so I can understand the real needs and prioritize this work accordingly.

[jalipert]

I am excited for the changes in v3, but we've used the v2 library extensively to allow users to mark up images in our application, and the states are stored to a database so they can be recalled and loaded back to the images, and edited as needed. We would really benefit from having a way to convert v2 states to v3 states, even if it is a separate script to do the conversion perhaps.

[ailon]

Thank you for the feedback, @jalipert!

Do you use (expose to users) the full set of marker types or just a subset that makes sense in your project?

[jalipert]

We use most of the marker types, here's the full list we use in our project from v2:

Frame
Ellipse frame
Highlight
Callout
Arrow
Freehand
Line
Ellipse
Cover
Text
Measurement
Curve

I can run some stats on the database to find out the frequency of each. It's possible some are not used frequently.

[ailon]

@jalipert thanks! No need for stats. In any case Text would be the most challenging part.

[jalipert]

@ailon Text and Callout is used frequently in our case, and always configured with the wrapText = true setting