mfilename not working on Live Editor?

Hi. I'm using matlab 2016a. Inside a Live Editor script, I'm trying to get the script name, using the function mfilename, without any parameters, to get it. What matlab gives as an output is: MatlabEvaluationHelper.

I've tried to export this code to a classic matlab .m file, and seems to work fine. Any idea on what could be the problem? Thanks in advance

Answer 1

[Cam Salzberger]

Hello Jaime,

I am afraid that mfilename does not function inside live scripts or functions. Our developers are aware of this feature request, and are considering possible resolutions for future releases of MATLAB.

Can you describe what you are trying to accomplish with "mfilename"? There may be other ways to get a similar workflow to what you desire.

-Cam

[Jaime López]

Well. Even when I have only written the .mlx file, to share it with some coleagues I use the .m file, (just by saving the current file as a new .m one). In this new .m file, I want to arrange some figures in the screen, modifying both position and size, but I don't want that changes to affect the .mlx file, so I waas planning on adding an if clause, that checked the current file name (and extension if possible) to resize the figures only if it is a .m file.

[Jaime López]

Currently I'm doing the trick just based on that mfilename output, using: if strcmp(mfilename, 'MatlabEvaluationHelper') ... end

[Cam Salzberger]

Hmm, I'm not sure it would have worked either way. "mfilename" specifically does not include the file extension, so you couldn't just look for ".mlx" or ".m".

Your solution seems good for now, but there is an issue with consistency across releases. For example, on the latest release, the result mfilename is something like "LiveEditorEvaluationHelperE799522741". You could just check for if the result of mfilename matches the known name of the file, but in the future, mfilename's behavior in live scripts may change to match that in regular scripts.

One trick you can use, for now at least, is to check the visibility of the figure immediately after creation. In Live Editor, the figure 'Visible' property defaults to 'off', whereas it defaults to 'on' in regular scripts (assuming no defaults are set in the graphics root to contradict this). This should be a simple way to tell the environment, for at least R2016a through R2017b.

Hope that helps!

-Cam

[Jaime López]

Consistency across releases is a must, because my coleagues don't always use the same version I'm using, so I'll try your approach. Lots of thanks

[Sean de Wolski]

If you want to arrange figures, you could call figure('Visible', 'on') which opens Live Script figures outside of the live script canvas.

[Mate D]

Hello,

is there any update on the progress of this function in live script or any workaround ?

[Cam Salzberger]

This answer lists a workaround for Live Scripts that should work for most people. As far as I'm aware, it's still the best answer so far.

[Chris Jennings]

Ummm ... that workaround doesn't work.

Its very annoying that Live Editor doesn't support mfilename or an equivalent, and it's taking way to long for this to be fixed. I have many harc copy plots that I used to print filename on for traceability. Now I have to HAND ANNOTATE, which is error prone and time consuming.

[Jan Kappen]

This is the solution (from Get path from running script - (mathworks.com)):

filePath = matlab.desktop.editor.getActiveFilename;
fprintf('%s\n',filePath);

[Mike Alger]

hmm that doesn't seem to return anything in 2018b was this added later on?

running it in the script or on the command window with with a mlx file open in the editor yeilds the following:

matlab.desktop.editor.getActiveFilename
ans =
0×0 empty char array

[Ornit]

mfilename still does not work properly in live editor, R2022a. Returns some location on my C drive (while the script is in fact running on a network drive).

However, Jan Kappen idea (filePath = matlab.desktop.editor.getActiveFilename; from 13 Jan 2022) works perfectly. Thanks!

[Bradley Stiritz]

Thank you Jan Kappen for the workaround! and thanks Omit for the +1

After 5 years, it would be nice if the mfilename doc page could be updated to mention the limitation and workaround.

Answer 2

[John Brown]

General

mfilename() does not work because live scripts use a temporary "live editor evaluation helper file," so mfile is evaluated there. I too found myself wishing that mfilename() did work and so I went ahead and made myself a few helpers; among them is currentFile() which I'll go ahead and dropin the event you're.

Full warnings:

• dbstack() isn't great for performance and Mathworks documentation explicitly warns its best to be avoid programmatically because of this.
• Im using a simplistic string match to check for live script mode, this could break in the future.
• I have included the dependency dbstack_() and its internal functions; If you wrap up dbstack_() and the two function after it into a file then wrap currentFile() into another function file this should work just fine.
• In the event you want to debug this in any capacity, or are notice weird behavior, note that the method of gathering the current file in the event a live script is the caller, is checking the open file in the editor. This means if you put a breakpoint down in the function and step over the call that grabs the open file, you wont get the result you would in the standard case. This also applies if you were to run a live script file using this method and then change the open editor file before execution of the function. That said these seem unlikely and for most practical use cases this works wonderfully.

Usage

To use the function and return the filename, (which in the event the file is unsaved will return untitledN, I prefer this but you could easily modify that) you simple call:

filename = currentFile();

If you would prefer the absolute path of the file, you can call the function with "fullpath." In the event that the file is unsaved the path returned will be equivalent to fullfile(pwd(), "untitledN") ie the path youd see if you were to save it in the current workspace. Note that Ive not yet made the appropriate change to check user settings and append the .m vs .mlx so the returned filename of unsaved scripts will lack an extensions:

filename = currentFile("fullpath");

Function Definitions

currentFile() Function File Contents:

This function will return the file name of the caller. If the stackUpCount variable is specified the number of items to be removed from the stack can be specified. This function has be written to work with live script execution where mfilename() fails to provide the file name, this function determines if the caller is a live script and uses alternative functionality to return the path of the file that is being run as a live script.

Note: Because the function uses the matlab.desktop.editor.ActiveFilename() method, you must be in the caller file during execution of this script for it to work. This is normally not an issue unless you are stepping into this function; doing so makes this function the active file, thus producing incorrect output.

function [filePath, lineNumber] = currentFile(pathType, opts)
    arguments
        pathType (1, 1) string {mustBeMember(pathType, ["", "fullpath"])} = "";
        opts.StackCount (1, 1) double {mustBeInteger(opts.StackCount)} = 0;
        opts.IncludeExtension (1, 1) logical = true;
        opts.OutputFormat (1, 1) string {mustBeMember(opts.OutputFormat, ["Uniform", "Struct", "Table"])} = "Uniform";
    end
    
    % Calls dbstack to get information about the caller
    stack = dbstack_(pathType, "StackCount", opts.StackCount + 2, "IncludeExtension", opts.IncludeExtension);
    stack = stack(1);

    % Assigns the line number
    lineNumber = stack.line;

    % Handles conforming to desired output format
    switch(opts.OutputFormat)
        case "Uniform"
            filePath = stack.file;
        case "Struct"
            filePath = stack;
        case "Table"
            filePath = struct2table(stack);
    end
end

dbstack_() Function File Contents:

Similar to the built in dbstack but will replace instances of the live script helper file with the currently open editor file.

function stack = dbstack_(pathType, opts)
    arguments
        pathType (1, 1) string {mustBeMember(pathType, ["", "fullpath"])} = "";
        opts.StackCount (1, 1) double {mustBeInteger(opts.StackCount)} = 1;
        opts.IncludeExtension (1, 1) logical = true;
    end

    % Calls dbstack to get information about the caller
    stack = dbstack(opts.StackCount, "-completenames");

    % Gathers the stack info for live script substitution
    eStack = struct2table(editorStack());

    % Handles determination of output when caller is live script execution
    if(isempty(stack))
        stack = eStack;
    else
        % Normalize stack for modification
        stack = convertCharsToStrings(struct2table(stack));
        stack = convertvars(stack, ["file", "name"], "string");

        % Changes the files referencing a live script helper
        needsModified = referencesLivescript(stack.file);
        stack.file(needsModified) = strings([sum(needsModified), 1]) + eStack.file;

        % Changes the names referencing a live script helper
        needsModified = referencesLivescript(stack.name);
        stack.name(needsModified) = strings([sum(needsModified), 1]) + eStack.name;
    end

    % Separates the elements of the file path
    [folder, name, ext] = fileparts(stack.file);

    % Includes extension if desired
    if(opts.IncludeExtension)
        name = name + ext;
    end

    % Handles rebuilding file appropriately
    if(pathType == "fullpath")
        stack.file = fullfile(folder, name);
    else
        stack.file = name;
    end

    % Converts to struct to maintain consistency with dbstack()
    stack = table2struct(stack);
end

Returns a structure array compatible with the return of dbstack() using the active live script instead.

function stack = editorStack()
    % Gather the active file
    stack.file = string(matlab.desktop.editor.getActiveFilename);

    % Builds file path if file were saved in the current directory
    if(~isfile(stack.file))
        stack.file = fullfile(pwd(), stack.file);
    end

    % Gathers the name 
    [~, name] = fileparts(stack.file);
    stack.name = name;

    % Gathers currently selected line
    stack.line = matlab.desktop.editor.getActive().Selection(1);
end

Determines whether the string refers to a live script evaluator.

function b = referencesLivescript(str)
    arguments
        str string;
    end

    % Determines if the caller is a live script being run in the editor
    liveScriptStrCmp = "LiveEditorEvaluation";
    b = str.contains(liveScriptStrCmp, "IgnoreCase", true);
end

[John Brown]

For completions sake, here is the folder equivalent mirror of currentFile(), currentFolder(), that just strips the folder from the path as well:

currentFolder() Function File Contents:

Returns the folder of the currently running file. This function uses currentFile() so if you find weird behavior with this function the cause is likely from currentFile().

function folderPath = currentFolder(pathType, opts)
    arguments
        pathType (1, 1) string {mustBeMember(pathType, ["", "fullpath"])} = "";
        opts.StackCount (1, 1) double {mustBeInteger, mustBeGreaterThanOrEqual(opts.StackCount, 0)} = 0;
    end

    % Gathers the full folder path of the current running file
    [folderPath, ~] = fileparts(currentFile("fullpath", "StackCount", opts.StackCount + 1));

    % Removes the absolute path from the folder path
    if(pathType == "")
        [~, folderPath] = fileparts(folderPath);
    end
end