state-machine

I have a problem at hand and I am not getting which design pattern to use. The problem goes as such: I have to build a system which has 'N' states and my system has to do a transition from any state to any other state depending on some conditions. Ex: On condition 1, movement from State 1 to 3 and on condition 2 from state 1 to 4. Even the transition from one state to other state can be done on 2 or more different conditions. For example, transition from State 1 to state 3 can be done when: condition 1 : "Its a Sunday" condition 2: "Its Raining" condition 3: "Its Raining and Sunday" In each

Does anybody know a workflow engine (such as Spring WebFlow) for Javascript? We have a home-made framework that allows us to guide site navigation using JSON, but its quality is far from good. Edit based on given answers: the engine must run on the browser and reduce to minimum the number of requests to the server. eabait As suggested by katspaugh I'm posting the libraries I found as the answer. List of workflow libraries that I've found until now: XState - https://github.com/davidkpiano/xstate Workflow.js for Backbone.js https://github.com/kendagriff/workflow.js Sprout Workflow Engine https:/

We are using state_machine ( https://github.com/pluginaweek/state_machine ) in a project and would like to offer a form with a select that lets us choose a state. (this is for searching, not for setting). I can't seem to find a way to list out all the possible states? Surely there should be an automatic way of doing this, not having to hard-code a list of text somewhere. Thanks! Something like: User.state_machine.states.map &:name Just to add to this (because I'm constantly searching for this answer, and I always come back to this page), if you are trying to list the states for a giving state

I am attempting to build an FSM to control a timer in (iphone sdk) objective c. I felt it was a necessary step, because I was otherwise ending up with nasty spaghetti code containing pages of if-then statements. The complexity, non-readability, and difficulty of adding/changing features lead me to attempt a more formal solution like this. In the context of the application, the state of the timer determines some complex interactions with NSManagedObjects, Core Data, and so forth. I have left all that functionality out for now, in an attempt to get a clear view of the FSM code. The trouble is, I

I'd like to know about specific problems you - the SO reader - have solved using Workflow Engines and what libraries/frameworks you used if you didn't roll your own. I'd also like to know when a Workflow Engine wasn't the best choice and if/how you chose something simpler, like a TaskList/WorkList/Task-Management type application using state machines. Questions: What problems have you used workflow engines to solve? What libraries/frameworks did you use? When did a simpler State Machine/Task Management like system suffice? Bonus: How did/do you make the distinction between Task Management and

I need to match certain URLs in web application, i.e. /123,456,789 , and wrote this regex to match the pattern: r'(\d+(,)?)+/$' I noticed that it does not seem to evaluate, even after several minutes when testing the pattern: re.findall(r'(\d+(,)?)+/$', '12345121,223456,123123,3234,4523,523523') The expected result would be that there were no matches. This expression, however, executes almost immediately (note the trailing slash): re.findall(r'(\d+(,)?)+/$', '12345121,223456,123123,3234,4523,523523/') Is this a bug? There is some catastrophic backtracking going on that will cause an

In what areas of programming would I use state machines ? Why ? How could I implement one ? EDIT: please provide a practical example , if it's not too much to ask . In what areas of programming would I use a state machine? Use a state machine to represent a (real or logical) object that can exist in a limited number of conditions (" states ") and progresses from one state to the next according to a fixed set of rules. Why would I use a state machine? A state machine is often a very compact way to represent a set of complex rules and conditions, and to process various inputs. You'll see state