This repository is deprecated

Caution

This repository is no longer needed, as a function rpgm.open() has been added in RPGM. More info: https://docs.pgm-solutions.com/rpgm/latest/api/r/rpgm/#rpgmopenfile

File Download for RPGM Server

This repository is literally a hack for allowing RPGM Server to download files without using rpgm.addToEndScreen() and waiting for the final step. Typically, the user will press a button for initiating the download. In desktop RPGM, it will simply open the file with shell.exec.

In future RPGM versions, downloading a file in RPGM Server will be a native feature with new R functions. This is just a temporary fix.

Please also note that executing custom Javascript is an upcoming feature in RPGM, so injecting Javascript code is not considered as a security issue. You are supposed to execute PGM files the same way you execute binary or exe files: by trusting the developper.

Usage

Add this CSS code in your project settings, "CSS" tab:

.downloaderURL {
    display: none;
}

This will hide the widget which will make the download working.

Then include in your sequence the file-utils.R file in the beginning of the project. Before entering the GUI which will trigger the download, call download.init(rpgm.step(...)) with the correct step. Lastly, in the callback of your button, call download.go(rpgm.outputFile(...)) or download.go(rpgm.pgmFilePath(...)).

How it works

• download.init() adds two widgets: a hidden text field and a hidden label with a fake image which will load a javascript code. This JS code will put the current URL address in the hidden text field.
• The user will click on a button or another R callback which will populate the variable downloaderURL in R with the current URL address.
• download.go will execute shell.exec if no URL is found, or will craft the final URL of the file for the browser.
• With the final file URL, the invisible label is updated again with a fake image with a JS payload for opening the URL in another window or tab.