Ink Canvas v2 - Multiple Canvas (Grading table)

Multiple canvas — grading table

One row per participant, one small InkCanvas instance per criterion column - a grid of independent handwriting fields instead of a single free-form canvas.

Each grade cell uses recognition.type: 'MATH' (a handwritten number is a math expression), while the Comment column uses recognition.type: 'TEXT' - two recognition types mixed on the same page, one canvas instance per cell.

Grades are out of /20. Each grade cell's exported event is checked as soon as recognition completes: if the written value isn't a number or falls outside 0-20, the cell is cleared automatically and an error message is shown under it.

"Get summary" calls canvas.export() on every grade cell of a row, sums the parsed numbers into the Total column, and lists each participant's total plus their comment in the report below.

Canvas.load() is not used here: it keeps a single instance per canvas type and destroys the previous one on every call, which breaks with several concurrent INK_V2 instances (12 of them on this page). Constructing new InkCanvas(fieldEl, options) directly (still a public export) sidesteps that and gives each cell a fully independent instance.