Bulk export/scriptable SVG export for circuit

[johndoe31415]

Hi there,

hope this is the right place to open a discussion. Maybe someone has a good solution and/or idea as to how I could implement this. I'm using circuitjs for presentations in which I teach digital electronics. Right now my workflow is: build the circuit in circuitjs, export it (either via text or link), put it in my slide generator. Additionally, I export the SVG of the circuit to be able to easily embed the link into my presentation.

Sometimes I do make small changes to the presentation and forget to update the SVG. Sometimes I mis-place the circuit, so that it appears as one cirucit, but clicking on it opens an entirely different circuit.

The way I see it, the circuit definition is the authoritative definition file. I would like to have a way to bulk create SVGs from a circuit definition, e.g., an endpoint that I pass a link to ("ctz=foobar") and it just outputs the SVG. Possibly after simulating after a second or so to achieve a steady state.

Alternatively I've thought about parsing the circuit definition and writing my own renderer that outputs SVG, but I'd like to avoid that if possible (I want to have the same look & feel).

Do you have an idea where I could approach this to get it done?
Thanks,
Joe

[pfalstad]

Maybe there could be a script that the simulator folllows.

wait 5 seconds
load file xxx
wait 3 seconds
export svg
load file yyy
wait 3 seconds
...

[pfalstad]

I mean this interface: https://www.falstad.com/circuit/jsinterface.html

It can be used to start/stop the simulation and access circuit data, but can't be used to trigger menu items, yet.

The websocket interface could be built on top of that.

[johndoe31415]

That looks amazing, I'll take a peek!

[johndoe31415]

Did some work. The JS interface definitely is the way to go! This is awesome. Check it out: master...johndoe31415:circuitjs1:circuitws

Using this, a Python Websocket server starts up and waits for circuitjs to connect to it. Once it does, we can send all exposed commands to the JS interface as we like. I've exposed all functionality that you currently offer.

What is missing for my concrete use case:

• Load circuit (from "ctz" string or full circuit .txt definition)
• Save circuit
• Get circuit SVG

What could also be useful is to expose the elements that getInfo() offers not only in their textual representation, but as bare values (right now it's something like "V = 1.234µV", which means it would be cumersome to parse).

Do you think that could be doable easily? I'll try to see if I can get it done myself, but no promises ;-)

EDIT: I've now also pushed something for SVG export. It works nicely and wasn't too difficult, but I do think the solution is quite ugly, since it exposes the script injection to the external API. However, I'm not proficient enough in Java to implement some event/future/etc. mechanism to actually stop the call until the callback has returned (successfully or unsuccessfully). So that's what it is for now. I'll also look at implementing the other functionality that I'm interested in. This is going to make this so versatile when I can use everything from Python, I love it :-)

[johndoe31415]

OK, so this looks very promising. I got done everything that I need for my use case. Cleaned up the commit history so that each feature has its own commit and no mixing. Fixed whitespaces and so on. Would love to merged this as a PR, if you tell me what else you like to see changed, I'd do that before I create one.

One question is the location of the Python script, which you certainly don't want in the root directory -- but I didn't find a good spot tbh.

[pfalstad]

Looking great! Although I think the SVG stuff should take a callback to provide the result, rather than returning a result. I would not expose the SVG initialization (initializeSVG, isSVGInitialized). I can clean that up if you want.

The websocket stuff can go in a new directory, "websocket".

Well done!