Category: Technology

Adding member to MS Teams without admin rights or Graph API

# To run on Linux, you need the preview mode of AzureAD
# Register-PackageSource -Trusted -ProviderName ‘PowerShellGet’ -Name ‘Posh Test Gallery’ -Location https://www.poshtestgallery.com/api/v2/
# Install-Module -Name AzureAD.Standard.Preview

# Windows, the module is
# Install-Module -Name AzureAD

# I’m lazy and just typed my creds for a proof of concept; real implementation would use the SecureString thing in the connect-azuread. See:
# https://www.rushworth.us/lisa/?p=3294
connect-azuread

# Get the object ID for the group and the user
$objMyGroup = get-azureadgroup -SearchString “LJR Sandbox Team”
$objNewMember = get-azureaduser -searchstring “NewGuy”

# Add the user to the group
add-azureadgroupmember -ObjectID $objMyGroup.ObjectId -RefObjectID $objNewMember.ObjectId

Composer Hangs

I don’t use composer often, and it generally just works … so I don’t know much about it beyond “another package manager”. But every once in a while, it just hangs. Nothing happening, nothing instructive in strace. Fortunately, composer has several levels of verbosity on the output. While the default output is minimal and offers absolutely no clue that it’s doing something … adding -vvv is a nicely verbose output that lets me see that the package install isn’t actually hung. It’s just going to take a long time.

Excel – Setting a Cell Value Based on Background Color

I need to programmatically parse an Excel file where items are grouped with arbitrary group sizes. We don’t want the person filling out the spreadsheet to need to fill in a group # column … so I’m exploring ways to read cell formatting so something like color can be used to show the groups. Reading the formatting isn’t a straight-forward process, so I wondered if Excel could populate a group number cell based on the cell’s attributes.

While it is possible, it’s not a viable solution. The mechanism to access data about a cell cannot be accessed directly and, unfortunately, requires a macro-enabled workbook. The mechanism also requires the user to remember to update the spreadsheet calculations when they have finished colorizing the rows. While I won’t be using this approach in my current project … I thought I’d record what I did for future reference.

We need to define a ‘name’ for the function. On the “Formulas” tab, select “Name Manager”.

Select ‘New’

Provide a name – I am using getBackgroundColor – and put the following in the “refers to” section: =GET.CELL(63,INDIRECT(“rc”,FALSE))

Now we can use this name within the cell formula:

Select the rows for your first group and change the “fill color” of the row.

Repeat this process to colorize all of your groups – you can re-use a color as long as adjacent groups have different colors. Notice that the “ColorGroup” values do not change when you colorize your groups.

On the “Forumlas” tab, select “Calculate Now”

Now the colorized cells will have a non-zero value.

OpenHAB CalDav Personal Binding – Item Name Filtering

We use the CalDav Personal binding to select items from our Exchange calendar to populate date/time OpenHAB Items — when does Anya have her next gymnastics class, when is the next Trustee meeting, etc. When we had first set this up, we were using manually created appointments. The appointments were assigned unique categories so the binding could determine which appointment should be used to update the Item. I’ve since started creating calendar items based on published calendars (so far a Google calendar and a SchoolPointe calendar), but the Python module for interacting with Exchange cannot assign a category to the appointments it creates.

The binding allows you to filter on the appointment subject (‘name’) using a regex. The binding documentation says to use name-filter:’\<Some Filter\>’ which … well, doesn’t work. We tried omitting the back-slashes in case they were meant to be escape characters. We tried omitting the greater and less-than symbols in case those were meant in the way I often use them, to designate <the part you replace>. Still doesn’t work. We tried using forward-slashes instead of backslashes because that’s the normal regular expression syntax. Nope. We tried adding a ‘starts with’ ^, trailing .* to ensure it would match anything that started with what we wanted. Nope. We’d alternately match all of the appointments or none.

Consulting the source, there is a very restrictive character set available in your name filter regex. The binding uses Java’s Matcher with a regex to extract your regex from the item configuration. You need to have filter-name: then you may have a single quote (‘? means 0 or 1 of ‘). This is Followed by one or more characters from the class which is all upper and lower case letters A-Z, a full stop, an asterisk, a plus sign, a minus sign, a space, and a pipe bar. Then you may have another single quote. The bit with one or more characters from the restricted class is extracted — this is how the binding gets your regex from the item config.

private static final String REGEX_FILTER_NAME ="filter-name:'?([A-Za-z\\.\\*\\+\\- \\|]+)'?";

Using unsupported characters in your filter-name regex alternately match all appointments or none. Using filter-name:’\<test>\’ (as the documentation literally instructs me to do) doesn’t return a match with anything as + requires one or more matches from the character set. I have zero such characters after the opening single quote. Similarly filter-name:’^Beginning of string.*’ doesn’t return a match. It appears that, in cases where the name filter is null … all items are matched. Explains why we were getting the same appointment’s details posted into each item.

On the other extreme — a filter like filter-name:’Pick up dry-cleaning at 1 Main Street’ will truncate your regular expression at the number character. The extracted matched group is Pick up dry-cleaning at … which won’t match anything unless you actually have an appointment titled “Pick up dry-cleaning at ” with a trailing space. I’ve seen posts on the OpenHAB forum where individuals have non-English words in their match … filter-name:’Trip to Askøy’ which, again, match nothing since the actual regex used by the binding is Trip to Ask  The same thing happens when looking for character classes (i.e. I don’t know if this will be capitalized, so I want to match [Tt]est).

The solution, since a question mark isn’t an option, is to use a plus or splat to replace any character that isn’t supported by the binding. Using a plus ensures there’s something where you expect the character to occur, although the * is a broader match (we use “Township: Event Name”, but I don’t need the colon to successfully match my item. “Township Event Name” would match. I could even use a different delimiter as “Township, Event Name” would also match). Where you are unsure of the case, you need to use a pipebar (e.g. filter-name:’Test|test’)

The Items that are populated with the start time and event name for the next Township meeting look like this:

DateTime Calendar_Upcoming_Township "Upcoming Township meeting (start) [%1$tA, %1$tB %1$te, %1$tY at %1$tl:%1$tM%1$tp]" <calendar> (gCalendar) {caldavPersonal="calendar:ourcalendar type:UPCOMING eventNr:1 value:START filter-name:'Township. .*'"}
String Calendar_Upcoming_Township_Title "Upcoming Township meeting [%s]" <calendar> (gCalendar) {caldavPersonal="calendar:ourcalendar type:UPCOMING eventNr:1 value:NAME filter-name:'Township. .*'"}

And the calendar events titled “Township: Trustee Regular Meeting” or “Township: Craft Fair” are all identified by the filter.

Note: Scott submitted a PR to change the regex used to extract your filter-name regex. Once this change gets merged, you’ll be able to use character sets (e.g. [T|t]est), numbers, and ‘special’ characters excluding the single quote. Including the single quotes around the filter will be required.

Scraping Calendar Events

We’ve learned the value of engaging with local government — with few people involved in local proceedings, it’s pretty easy for a generally unpopular proposal to seem reasonable. And then we’re all stuck with the generally unpopular regulation. It is a pain, however, to keep manually adding the next Trustee meeting. And there’s no way I’m checking the website daily to find out about any emergency meetings.

Now I’m pulling the events from their Google calendar and creating new meeting items in my Exchange calendar:

  1. Register the app with Google to use the API
  2. Install exchangelib
  3. Copy config.sample to config.py and add personal information
  4. Create a ca.crt file with the CA signing key for your Exchange server (or remove the custom adapter if your server cert is signed by a public key)
  5. Run getCalendarEvents.py and follow the URL to authorize access to your calendar

I’ve tweaked the script to grab events from the school district’s calendar in SchoolPointe too. Now we know when there’s a school board meeting or dress-up day.