FoxGet Package Manager

If you've worked with Visual Studio, you've likely used NuGet, which is a package manager for .NET. The idea is that you can search for libraries you'd like to add to your application, download and install them, and then have them managed (automatically download again if files are missing, update to a new version, etc.). FoxGet is the VFP equivalent of NuGet.

The idea is that you run FoxGet when you want to add a library to an application. You search for a library you're interested in and if one is found, you can download, install, and add it to your project with a single mouse click. Of course, you'll have to do the coding part such as calling the library yourself.

Note: in this documentation, "package" means a library you want to add to your application.

Using FoxGet

Open the project for your application and DO FoxGet.app in the FoxGet folder.

Select a package to see information about it at the right, including the version and date the package was installed in the project if it was installed. Click the link for Project URL to go to the home URL for the package.

You can search for a package by name, tag, or description by typing in the Search textbox. To show only packages installed in the current project, turn on Show only installed packages.

To install the selected package, click Install; that button is disabled if the package has already been installed. After a moment, you should see that some files were added to the project and there's a Packages subdirectory of the project folder containing Packages.dbf and the downloaded files in a subdirectory for the component. The package subdirectory also contains a file named PackageInstaller.prg, which is used to uninstall the package.

You may wonder why FoxGet puts the library into subdirectory of the Packages subdirectory of the project folder rather than in a common location other applications could reference. There are several reasons:

• That's the way NuGet works.

• If your application is in source control (such as Git), it isn't easy to include paths outside the application path in the repository.

• You may want to use different versions of a library in different applications, especially if how you call the library changes between versions.

Since packages go in their own folders, you'll need to set a path to those folders if you run the application in the VFP IDE.

To uninstall the selected package, click the Uninstall button. The files added to the project by the installer are removed from the project, the package folder in the Packages subdirectory is deleted, and Packages.dbf is updated.

If there's a newer version of the package available, the Update button is enabled. Clicking it uninstalls the package then installs the new version.

Dependencies

Some projects depend on other projects. For example, ErrorHandler uses SFMail, which itself uses wwDotNetBridge. FoxGetPackages.dbf, which contains information about each package, has a Dependent column containing the names of other packages a package is dependent on. When you install a package, all dependencies are also installed (any that are already installed are reinstalled). When you uninstall a package, dependencies may be uninstalled as well, as long as no other packages depend upon them and they weren't installed as a standalone package.

Note that dependencies go in their own package folders, so you'll need to set a path to those folders if you run the application in the VFP IDE.

How is FoxGet different from Thor Check for Updates

Thor has a Check for Updates (CFU) feature that can install and update projects. While this works very well for "tools", projects that are used within the VFP IDE like GoFish, it is less suitable for installing "components", projects that add features to your applications:

• Thor installs projects in a subdirectory of its own folder rather than under your application, making source code control and pathing trickier.

• Thor doesn't list all projects, only those the project manager has configured to work with Thor CFU. FoxGet doesn't list all projects either, but projects can be expanded without updating the repository of the project.

Creating an installer

If you interested in writing your own installer, check out the various installer PRGs in the Installers folder to see how little code there is, as FoxGet.prg takes care of most of the tasks. For some of them (e.g. CSVProcessor and DynamicForm), it's just specifying what files to download and which to add to the project. Others (e.g. ParallelFox and XLSXWorkbook) have more work to do, such as unzipping the download and copy some or all of the files to the package folder.

Here's a simple installer. It just downloads a single file and adds it to the project.

define class DPIAwareManagerInstaller as FoxGet of FoxGet.prg
    cBaseURL = 'https://raw.githubusercontent.com/atlopes/DPIAwareManager/master/source/'

* Define the file to download. Note that URLs are case-sensitive. Also, we'll
* download directly to the package folder since there's nothing to unzip, and
* we'll add the file to the project. Since FoxGet does all that, there are
* no custom tasks to perform.

    function Setup
        This.AddFile('dpiawaremanager.prg', .T., This.cPackagePath)
    endfunc
enddefine

Here are some notes:

• The installer program defines a subclass of FoxGet in FoxGet.prg.

• The installer class name and PRG must be the same and match the name in the Name column of FoxGetPackages.dbf with an "Installer" extension. For example, for the DPIAwareManager package, the installer name is DPIAwareManagerInstaller.prg and the class in that file is named DPIAwareManagerInstaller.

• Setup performs custom setup tasks and is normally used to define what files to download. The AddFile method called by Setup accepts three parameters:

  • The URL of the file to download. Note that URLs are case-sensitive. Also, if you're downloading more than one file from the same site, set the BaseURL property as this class does and then just specify the filename to download in AddFile. Note that for GitHub, the file isn't located at https://github.com/repository/branch/somefile but instead at https://raw.githubusercontent.com/repository/branch/somefile.

  • .T. to add this file to the project.

  • Optionally, a path to download this file to. If it isn't specified, the file is downloaded to a temporary path. In this case, since we don't have anything else to do with the file (such as extracting it if it's a ZIP file), we'll download directly to the folder for the package, specified in the cPackagePath property.

FoxGet creates the Packages folder if it doesn't already exists, creates a folder for the package in Packages, downloads all files you specified by calling AddFile, adds them to the project if the second parameter to AddFile is .T., and updates Packages\Packages.dbf. So, in this installer, there's nothing custom we have to do other than specifying the file to download.

Here's a more complicated installer.

define class XLSXWorkbookInstaller as FoxGet of FoxGet.prg
    cBaseURL = 'https://raw.githubusercontent.com/ggreen86/XLSX-Workbook-Class/master/'

* Define the file to download. Note that URLs are case-sensitive.

    function Setup
        This.AddFile('WorkbookXLSX%20R39.zip')
    endfunc

* Custom installation tasks: copy just the class library and include file from
* the extraction folder to the package folder and add the VCX to the project.

    function InstallPackage
        local llOK
        llOK = This.CopyExtractedFiles('vfpxworkbookxlsx.*')
        llOK = llOK and This.AddFileToProject('vfpxworkbookxlsx.vcx')
        return llOK
    endfunc

* Custom uninstallation tasks: remove the VCX from the project.

    function UninstallPackage
        local llOK
        llOK = This.RemoveFileFromProject('vfpxworkbookxlsx.vcx')
        return llOK
    endfunc
enddefine

Here are some notes:

• There's only one file to download: a ZIP file containing the project files.

• InstallPackage is a method where you can put custom installation tasks. FoxGet automatically extracts a ZIP file to a temporary folder so in this method we'll copy just certain files (vfpxworkbookxlsx.vcx, vct, and h) to the package folder; we'll skip the documentation and sample code. We'll also add the vcx to the project. Since each step could fail for some reason, we check the return value and only continue if it succeeded.

• UninstallPackage is a method where you can put custom uninstallation tasks. In this case, since we manually added the file to the project, we have to call RemoveFileFromProject to remove it.

To test your installer, create a record for it in MyPackages.dbf in the folder where FoxGet.app is located and specify the path to the installer PRG in the InstallURL field (for example, "C:\FoxGet\TestInstaller.prg"). Create a test project in a test folder, run FoxGet.app, and install your package. After testing is complete, you can delete the record in MyPackages.dbf (or not; see below).

To deploy your installer, do one of the following:

• Fork this repository, copy the installer PRG in the Installers folder, add a record for it to FoxGetPackages.dbf in the Installers folder, and create a pull request.

• Create the installer, create a new Feature Request (under Issues) in this repository, attach the PRG, and specify the values for the FoxGetPackages record.

• If you don't want to share your installer, just leave the record in MyPackages.dbf. The installer will only be available for you.

Helping with this project

See How to Contribute to FoxGet for details on how to help with this project.

Releases

See the change log for release information.