Announcing Virtual Fox Fest May 2021

We had so much fun at Virtual Fox Fest 2020 that we’ve decided to do more online conferences. They won’t all be three-day events; in fact, the next one (Thursday, May 6, 2021) is a one-day event. However, it’ll still have the same great features everyone loves about VFF: great speakers delivering great sessions, live chatting during presentations, and getting to hang out virtually with new and old friends. This event will feature classic sessions from Southwest Fox, updated for 2021. Registration is available now so sign up today! We’re still discussing whether to hold Southwest Fox in Arizona this fall. We expect to announce our plans for a fall conference by the end of March.

Changing Execution Priority on Demand

Recently, a friend asked me if it was possible to change the execution priority for some tasks on the fly. The issue was that when a user on a terminal server runs a report in Stonefield Query, which can be computing intensive as it retrieves and massages the data required for the report, other users may experience slower response. I did some research and it turned out to be easy to do, thanks to Rick Strahl's wwDotNetBridge.

The following code changes the priority for the running application to BelowNormal (see the documentation for the System.Diagnostics.ProcessPriorityClass enum for the different priority levels):

do wwDotNetBridge
loBridge = GetwwDotNetBridge()
loProcess = loBridge.InvokeStaticMethod('System.Diagnostics.Process', 'GetCurrentProcess')
loProcess.PriorityClass = loBridge.GetEnumValue('System.Diagnostics.ProcessPriorityClass.BelowNormal')

(This assumes you have wwDotNetBridge.prg included in your project and wwDotNetBridge.dll and ClrHost.dll in the current folder or VFP path.)

Use this code just before some process you want to run at a lower priority. Use similar code but a different value, such as Normal, to set the priority back again after the process is done.

As I have said many times, there's almost nothing we can't do in VFP with wwDotNetBridge.

Microsoft Office 365-like Ribbon Control

Merry Christmas! Every year between Christmas and New Year's, I like to work on a fun project, such as learning a new technique or writing some cool utility. Last year, I worked on the open source version of Hacker's Guide to Visual FoxPro. This year, I created an open source Microsoft Office 365-like ribbon control for VFP forms.

Here's a sample form containing the ribbon control that resembles Microsoft Outlook. It has two tabs: Home and Send / Receive. Clicking a tab displays the toolbar for that tab.

Here's the Send / Receive tab:

So far, I've included two themes: Colorful (above) and Dark Grey (below):

Themes are defined as RGB colors in an XML file so it's a simple matter to add another theme.

The ribbon control is 100% VFP code. Please try it out and let me know of any enhancements you'd like by creating issues in the GitHub repository for the project.

Help us plan the next Virtual Fox Fest

We have 11 quick questions to help us plan future Virtual Fox Fest conferences. We would really appreciate your input:

https://www.surveymonkey.com/r/F8ZLX9J

Happy Holidays and wishes for a healthy and prosperous 2021 to all.

Virtual Fox Fest 2020 Follow-up

Here are some follow-up notes about Virtual Fox Fest 2020, the first but likely not the last online event hosted by Geek Gatherings:

• Videos for all presentations are now available on YouTube for free to everyone, as our contribution to the VFP community. Be sure to subscribe to our channel.
• If you didn't attend Virtual Fox Fest and want materials (white papers and sample code) for the presentations, go to  https://geekgatherings.com/Registration and "register" for the conference. You're not really registering since it's over, but in the Registration Fees section of the registration page, you'll see "Virtual Fox Fest 2020 Session Materials (download)". The cost of the materials is $49. There's also an opportunity to sponsor Virtual Fox Fest, which means your name will be listed on our Sponsors page.
• We're planning on doing a survey soon. It'll be sent to all attendees but if you want to participate so you can help shape future events, email info@geekgatherings.com and ask to be included.
• We have tentative dates for an in-person Southwest Fox conference next year: October 14-17, 2021, at the same location as previous years: the SanTan Conference Center in Gilbert, Arizona. At this point, we don't know whether we'll be able to have an in-person event, but hope springs eternal!
• If you didn't attend Virtual Fox Fest, check out our Facebook page and see what you missed, then plan to attend a future one so you can join in the fun.

Default Git Message as a Pre-Commit Reminder

If you want a reminder when you commit in Git that you need to do something before committing, such as generating the text equivalents of binary files (something I occasionally forget to do if I working on something that doesn't use Project Explorer, which automatically does that for me), do the following:

• Create a text file anywhere you wish (named, for example, commit.txt) with the default message you want used in Git commits, such as “Remember to DO WHATEVER YOU NEED TO DO".
• Open a command window in the project folder (the one that has .git as a subdirectory).
• Type in a command window: git config commit.template “path\commit.txt”, where path is the full path for the text file you created.

Now, whenever you commit, the commit message defaults to “Remember to DO WHATEVER YOU NEED TO DO” (or whatever your message was), which of course you will then overwrite with the real commit message after you do what the reminder tells you to do.

Application Configuration using JSON

After watching Andrew MacNeill's Quasar and JSON: A Full Stack Experience for the DB Developer presentation at Virtual Fox Fest 2020, I was inspired to look at nfJSON, a VFX project by Marco Plaza. This cool project adds JSON support to VFP applications. The thing that tweaked my interest was the ability to convert a JSON string to a VFP object and vice versa with one line of code.

My first thought was using this for configuration settings. Just about every application needs configuration settings: it's better to read settings such as database connection information, file locations, email settings, etc. from a configuration source rather than hard-coding them into the app. I've used the Windows Registry, DBF files, INI, and XML files at various times but all of those require manually coding the reading and writing between the source and the VFP object(s) containing the settings. With nfJSON, it's one line of code.

I created a wrapper class called SFConfiguration. It only has three methods:

• Load returns an object with properties matching the name/value pairs in the JSON contained in the specified settings file. If the file doesn't exist or is empty (such as the first time the application is run), it calls GetDefaultSettings (described below) to get default settings.
• Save saves the properties of the specified settings object to the file specified in either the passed file name or the cSettingsFile property if a file name isn't passed.
• GetDefaultSettings returns JSON for default settings. You can use this one of two ways: subclass SFConfiguration and override GetDefaultSettings to return the desired JSON, or set the oSettings property to a settings object containing the default settings.

Here's an example of using this class to get email settings:

loConfig = createobject('SFConfiguration')
loConfig.cSettingsFile = 'email.json'
loConfig.oSettings     = createobject('EmailSettings')
loSettings = loConfig.Load()
* loSettings contains the email settings for the user;
* if email.json doesn't exist, the settings in the
* EmailSettings class below are used as defaults.
* After the user enters the desired settings in some dialog,
* save them using:
loConfig.Save(loSettings)

define class EmailSettings as Custom
    Email      = 'dhennig@stonefield.com'
    MailServer = 'mail.stonefield.com'
    Port       = 25
    UseSSL     = .F.
    UserName   = 'dhennig'
    Password   = 'mypw'
enddefine

Here's what the settings object looks like:

Here's what the saved JSON looks like:

Here's another example, this time using a subclass of SFConfiguration for the same thing:

loConfig = createobject('SFEmailConfiguration')

loConfig.cSettingsFile = 'email.json'

loSettings = loConfig.Load()
* loSettings contains the email settings for the user;
* if email.json doesn't exist, the settings in the
* SFEmailConfiguration class below are used as defaults.

define class SFEmailConfiguration as SFConfiguration
    function GetDefaultSettings

        text to lcSettings noshow

            {

                "email":"dhennig@stonefield.com",

                "mailserver":"mailserver.stonefield.com",

                "password":"mypw",

                "port":25,

                "username":"dhennig",

                "usessl":false

            }

            endtext

            return lcSettings

    endfunc

enddefine

Here's the code for SFConfiguration. It requires nfJSONRead.prg and nfJSONCreate.prg, which you can get from the nfJSON GitHub repository:

define class SFConfiguration as Custom
  cSettingsFile = ''
        && the name and path for the settings file
    cErrorMessage = ''
        && the text of any error that occurs
    oSettings     = ''
        && a settings object

* Load the settings from the file specified in the parameter
* or in This.cSettingsFile and return a settings object. If
* the file doesn't exist (such as the first time we're called),
* a settings object containing default settings is returned.

    function Load(tcSettingsFile)
        local lcSettingsFile, ;
            lcSettings, ;
            loSettings, ;
            loException as Exception
        try
            lcSettingsFile = evl(tcSettingsFile, This.cSettingsFile)
            if not empty(lcSettingsFile) and file(lcSettingsFile)
                lcSettings = filetostr(lcSettingsFile)
            endif not empty(lcSettingsFile) ...
            if empty(lcSettings)
                lcSettings = This.GetDefaultSettings()
            endif empty(lcSettings)
            loSettings = nfJSONRead(lcSettings)
            This.cErrorMessage = ''
        catch to loException
            This.cErrorMessage = loException.Message
            loSettings = NULL
        endtry
        This.oSettings = loSettings
        return loSettings
    endfunc

* Save the settings in the specified object to the file
* specified in the parameter or This.cSettingsFile.

    function Save(toSettings, tcSettingsFile)
        local lcSettingsFile, ;
            lcSettings, ;
            loException as Exception
        lcSettingsFile = evl(tcSettingsFile, This.cSettingsFile)
        if not empty(lcSettingsFile)
            try
                lcSettings = nfJSONCreate(toSettings, .T.)
                strtofile(lcSettings, lcSettingsFile)
                This.cErrorMessage = ''
            catch to loException
                This.cErrorMessage = loException.Message
            endtry
        else
            This.cErrorMessage = 'Settings file not specified.'
        endif not empty(lcSettingsFile)
        return empty(This.cErrorMessage)
    endfunc

* Gets the default set of settings as a JSON string; override
* this in a subclass if necessary.

    function GetDefaultSettings
        local lcSettings
        if vartype(This.oSettings) = 'O'
            lcSettings = nfJSONCreate(This.oSettings, .T.)
        else
            lcSettings = '{"text":"some text"}'
        endif vartype(This.oSettings) = 'O'
        return lcSettings
    endfunc
enddefine

Sending Email from VFP Applications: Supporting Newer SMTP Protocols

There are many libraries you can use to send emails from VFP applications. I created my own several years ago: a C# wrapper class using the .NET SMTPClient class, which I call using Rick Strahl's wwDotNetBridge. However, as discussed here, Microsoft no longer recommends using this class because it doesn't support modern protocols (which I can attest to, thanks to several support tickets from customers). As suggested in the article, I've rewritten my wrapper class to use the open source MailKit project.

Here's some code that shows how to use this wrapper class:

local loMail, ;
   llReturn
loMail = newobject('SFMail', 'SFMail.prg')
with loMail
   .cServer      = 'MyMailServer.com'
   .cUser        = 'MyUserName'
   .cPassword    = 'MyPassword'
   .nSMTPPort    = 25
   .cSenderEmail = .cUser
   .cSenderName  = 'My Name'
   .cRecipients  = 'someone@somewhere.com'
   .cSubject     = 'Test email'
   .cBody        = 'This is a test message. ' + ;
      '<strong>This is bold text</strong>. ' + ;
      '<font color="red">This is red text</font>'
   .cAttachments = 'koko.jpg'
   llReturn      = .SendMail()
   if llReturn
      messagebox('Message sent')
   else
      messagebox('Message not sent: ' + .cErrorMessage)
   endif llReturn
endwith

Here's what the received email looks like. Notice the attached image and the formatted text.

The class supports the following:

• Text or HTML body: simply include HTML tags in the cBody property and SFMail automatically handles it
• Attachments: cAttachments is a comma-separated list of file names
• Normal, CC (the cCCRecipients property), and BCC recipients (the cBCCRecipients property): separate multiple email addresses with commas or semi-colons
• SMTP or MAPI (using Craig Boyd's VFPExMAPI.fll): set lUseMAPI to .T. to use MAPI or .F. (the default) to use SMTP
• Adjustable timeout (the nTimeout property, which is in seconds)
• Adjustable security settings (the nSecurityOptions property; see the MailKit documentation for the values). I find the default setting of 1 (Auto) works best for most servers.
• Diagnostic logging: set cLogFile to the name and pass of a log file; it will contain the dialog between MailKit and the mail server so you can debug any problems.

You can download SFMail and the supporting files from the Technical Papers page of my web site or directly from here.

Regretting not registering for Virtual Fox Fest?

 

Virtual Fox Fest continues this week and next on October 21 and 27, 2020! The posts on social media about the first day of Virtual Fox Fest are very uplifting, the sessions were informative and inspiring, and the camaraderie during the social time after the sessions was a lot of fun. Does this make you wish you were part of the fun and learning? No worries, you can still register before our next conference day on October 21st, and have access to all the conference materials and to videos of the sessions you missed. Head over to our Registration site.

The Fox Show: Virtual FoxFest 2020

Listen to Rick, Tamar, and I discuss Virtual Fox Fest 2020 with Andrew MacNeill on The FoxShow.

Virtual Fox Fest starts next week. If you haven't registered, there's still time: http://geekgatherings.com/registration. Want to know who else is attending? See https://virtualfoxfest.com/whoscoming.aspx.