Can Web Apps take input arguments?

I am setting up a server to process data uploaded to it remotely. I'm using Matlab Web Apps to do the processing but I need to provide the app with the location of the files. I have this all working in AppDesigner by supplying the app with input arguments but there does not seem to be any information on how these work in Web Apps or whether it is supported at all (at least, not in the list in the Matlab help about what AppDesigner features that aren't supported in Web Apps).

Does anyone know if this is possible/impossible and, if possible, how it works?

Many thanks in advance.

Answer 1

[Chris Portal]

Currently, it’s a limitation, but there’s a workaround. This is what the doc says:

https://www.mathworks.com/help/compiler/webapps/unsupported-functionality.html

“Opening files and folders on the client, or loading and saving files on the client via uigetfile, uiputfile, and uigetdir is not supported. As a workaround, MATLAB file I/O functions such as readtable, load, and fread will work if the file or folder is on a network location accessible by both the client and server.”

[Huub Bakker]

Hi Chris,

My question isn't about whether I can access the files (they are on the server so there is no issue) but whether I can tell the app where the files are. In the AppDesigner I do that by calling the app with the path to the files as an input argument. My question relates to how to do that with a Web App. Where does it get its input arguments from? Intuitively, you would think that it was part of the URL; something like "http://localhost:9988/webapps/home/session.html?app=handleFilesApp?inputArg1?inputArg2" but I can't find anything on how to do this nor anything that says that you can't use input arguments with Web Apps.

Can you point me in the right direction here?

cheers

Huub

[Chris Portal]

Ah, thanks for clarifying. There isn't a way of invoking a web app with an input argument right now. It is an open enhancement request for the team to work on. The only workaround I can think of is to have a text field in the app where you can enter in the path to the files.

[Huub Bakker]

Many thanks. I will find a workaround. Just needed to be sure that it wasn't supported.

[Klemen Peter Kosovinc]

Dear Hubb, did you maybe find the workaround? Did anything change with new release of Matlab (R2018b)? Thanks, Klemen

[Huub Bakker]

Yes. Just hardwire the location of a configuration file into the Web App and then load the file with the location of the files you want to work on. A bit more roundabout, but still OK.

[Julian Krebs]

Any updates with R2019b/R2020b? Read url parameters with something like "?denomerator =3x+8x&numerator=8x^2" would be very helpful for WebApps. Actual best solution is to save preferences in configuration file and read it form other WebApp, right? Is there any example code for this?

Thanks!

[Amir Abedin]

I guess there is no update yet