Are you aware that RStudio has its own Help resources at: https://community.rstudio.com/
As they created and maintain Shiny, perhaps you should post there. Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Tue, Dec 28, 2021 at 1:22 PM Grzegorz Smoliński <[email protected]> wrote: > > Thank you for all the comments. If this is not a problem, I would like > to continue this thread as for me a lot of questions are still open. > But if I should post other questions in different messages / topics, > please let me know. > > I didn’t answer Ivan’s question previously, but yes, my desired result > is indeed what debug() / debugonce() does and Ivan mentioned trace() > earlier also, so I have tried this. I thought that trace() will be > better in my case (than debug()) since I would like to be able to call > trace() from one environment and insert browser() (using trace()) to > the function defined in parent environment (still not sure if I > understand this concept of environments). > > Even if I would like to use it in an shiny app, I have started with > this example: > > ------------------------------ > > fun1 <- function() { > a <- 1 > a > } > > fun2 <- function() { > fun1 <- function(){ > b <- 2 > b > } > trace(fun1, browser, where = globalenv()) > } > > fun1() > fun2() > fun1() > > -------------------------------- > > So I was hoping to use trace inside child environment of global env, > i.e. set browser() using trace() to the body of function defined in > parent environment, but for sure I do not understand this since > trace() in my example above is putting the browser() function inside > fun1() function defined not in global environment, but in the body of > fun2(). I.e. I'm starting to browse the fun1() function with the local > variable 'b', not 'a' as I wanted. > > Can I ask for help with this? In other words, how can I refer to some > function from the parent environment (not necessarily defined in the > global environment) being in the child environment? > > Also, if I could ask - is the reversed operation possible? I mean - > can I refer to some function from the child environment being in the > parent environment? I guess not, because of ephemerality? > > As I mentioned, I'm thinking about all of this in the context of shiny > app and the shiny app which consists of multiple files, modules. I'm > thinking if I could refer to any function from any environment (or at > least to any function in any parent environment) from one place (one, > current environment) where I will call debug() or trace() to insert > browser() at the beginning of this chosen function. And by "any > function" I'm thinking about another thing problematic for me. If I > consider this example: > > ------------------------------- > mod.R inside R/ > --- > > mod_UI <- function(id) { > } > > name_mod <- function(input, output, session) { > fun1 <- reactive({ > a <- 1 > }) > } > > --- > app.R > --- > > library(shiny) > > ui <- fluidPage( > mod_UI("mod"), > textOutput("env") > ) > > server <- function(input, output, session) { > > name_mod("mod") > > output$env <- renderPrint({ > names(environment(name_mod)) > }) > > observe({ > #trace(fun1, browser, where = environment(name_mod)) > }) > } > > shinyApp(ui, server) > --------------------------------------- > I tried to refer to the fun1 in environment(name_mod) - if I'm not > wrong, this is my parent environment, where objects "mod_UI" and > "name_mod" exist, but obviously I'm doing this wrong, right? Because > here: "#trace(fun1, browser, where = environment(name_mod))" I have > tried to refer to the module environment, but I should refer to the > environment inside "name_mod". I don't know how to do this and here I > also would like to ask for help. > > I know this may not be the best place for questions regarding shiny, > but I think these questions are purely linked to environment topics. > > I also remember Bert's post about "body()" and yes, this seems to be a > better idea than my first try in my first post, but "trace()" and > "debug()" seem much easier as all I want is to insert browser(). But I > just can't get it, how to refer to functions in (any) other > environments. > > Thank you very much for all your help and I hope it is OK to keep asking :). > > pon., 27 gru 2021 o 18:28 Duncan Murdoch <[email protected]> > napisał(a): > > > > On 27/12/2021 8:25 a.m., Duncan Murdoch wrote: > > > On 27/12/2021 8:06 a.m., Grzegorz Smoliński wrote: > > >> Hi, > > >> > > >> I know it is possible to find the environment in which some object > > >> lives using the 'environment()' function and the name of this object, > > >> but how to modify code of this object after this? Below is MRE: > > > > > > You are misunderstanding the relation between environments and > > > functions. However, your understanding is also being messed up by a bug > > > in R, so it's not entirely your fault. > > > > Actually this isn't a bug in R, it is working as documented. For a > > detailed explanation, see the response to my bug report here: > > https://bugs.r-project.org/show_bug.cgi?id=18269 . > > > > For a quick idea: "complex assignments" are assignments where there is > > a complex expression on the left hand side, e.g. > > > > environment(test)$test <- ... > > > > The way these are documented to work (in the R Language Definition > > manual) makes intuitive sense when you are working with regular R > > objects, but environments are "mutable" objects: assigning them to a > > new name doesn't make a new copy, just a new reference. That causes the > > definition of the complex assignment above to work in an unintuitive way. > > > > Conclusion: you should avoid using calls like environment(f) on the > > left hand side of assignments, especially as part of a larger > > expression. Break up the statement into steps like I did below: > > > > > e <- environment(test) > > > e$test <- eval(parse(text = "function() 2")) > > > > The same advice would apply to a function that returned an R6 object or > > a mutable object from the methods package (which are really environments > > in disguise), as well as some other exotic objects. > > > > Duncan Murdoch > > ______________________________________________ > [email protected] mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ [email protected] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
