Create managable flowchart for documentation

Question

I would like to create a flowchart for complex codes (can be written in any language) and use it for documentation purposes. Do you know any open source solution?

The specifications I need are:

1. Flowchart generated from code (for instance XML) and not drawn by software (for instance Visio).

2. Being able to make a query from a complex flowchart (for instance find file name, variables etc.).

3. Being able to add/remove any part of code easily.

4. Being able to get different view for different usage (documentation, presentation).

Just to give you an idea what I am looking for: http://www.flowgorithm.org/ is very interesting, however the main problem is it is not open source.

Answer 1

Well, my go to when I want to draw anything at all from text input is GraphViz. See this page for samples for what it can do.

I was surprised not to see a flowchart in the gallery, but a quick Google found this page, which shows this code

digraph {
    label="How to make sure 'input' is valid"

    start[shape="box", style=rounded];
    end[shape="box", style=rounded];
    if_valid[shape="diamond", style=""];
    message[shape="parallelogram", style=""]
    input[shape="parallelogram", style=""]

    start -> input;
    input -> if_valid;
    if_valid -> message[label="no"];
    if_valid -> end[label="yes"];
    message -> input;
}

generating this diagram

is that good enough? If not, please give more info & we will try to help further. This is a very interesting question & I have starred it as favo(u)rite. I love generating diagrams, Message Sequence Charts, State/Event charts, etc from plain ascii text.