I’m working on developing a web UI in AngularJS & Bootstrap for an application whose backend processing is done in C++/ROOT. The C++ code draws histograms, formulas, etc. on TCanvas and saves those to .root files. I had hoped to use JSRootIO to display this TCanvas in the web UI.
I had a problem where if I scripted calls into JSRootIO to read the file and display a known TCanvas, the drawing would silently fail unless I added timeouts to wait for the file to load. However, I found this topic ( Design-time specifying hists to draw with ROOTjs class) that pointed me to creating a userCallback(file) function to use for calling showObject().