What Is Whitespace?

In some Java work I needed to scrub some NO-BREAK SPACE characters from some import data. In looking for a command in Java to trim the leading and trailing whitespace, I fell down a Rabbit Hole.

Turns out that the Java String class offers a trim command. But that command has a strange definition of whitespace. Read this blog post by Mike Kaufman for details. The upshot: 'trim' only deletes characters numbered 32 (U+0020, SPACE) and lower.

Then I find an interesting spreadsheet, whitespace? what's that?, listing the various definitions of whitespace in Java and Unicode. There is a lot going on in the nothingness of whitespace!

CharMatcher – Google Guava

Eventually I found a modern, flexible, easy-to-use solution: `CharMatcher` in Google Guava. See their brief guide. By making clever use of Predicate syntax, they make it easy to mix and match various groups of whitespace, invisible, and control characters. You can trim from the front and/or back of a string, replace, and more.

Example usage:

someText = CharMatcher.WHITESPACE.trimFrom( someText );


Just use 'TEXT' type in Postgres

Sometimes it is the little things that trip you up, especially when learning a new tool. Like which data type to choose when creating a new database in a SQL system. But not so simple.

Here are two posts that make a strong case for just using TEXT in Postgres while avoiding VARCHAR and CHAR. I agree. Wish I'd seen this long ago.

And for more info, experimentation, and discussion, see the post CHAR(X) VS. VARCHAR(X) VS. VARCHAR VS. TEXT by depesz.

The upshot is:
  • Use the TEXT type for all your textual needs.
  • If constraining the maximum, minimum, and content is important then define a CONSTRAINT. (No need to depend on the max length feature of varchar.)
As counter argument, see IN DEFENSE OF VARCHAR(X) by Leo Hsu and Regina Obe.


Chores In TestFlightApp

The TestFlightApp.com people provide an amazing service with relatively good documentation. Unfortunately they fail to provide the most simple doc for the regular chores. I only perform these chores only on occasion, and always forget the required steps.

So here’s a blog post to help remind myself. This information is for the old site before Apple acquired this company. Apple has begun pushing this service explicitly through Apple, but I continue to use the old web site; not sure if the new Apple way is different.

Add A New User

Someone wants to join my team of testers. They have no account on TestFlightApp.com.
  1. I login to TestFlightApp.com.
  2. I click the "Dashboard" tab in their web site.
  3. I click the third and last big green button, "Invite People".
  4. I enter their email address, and send an invitation.
  5. Wait for tester to do their part. Email goes out within minutes. If unreceived, remind tester to check their junk filters & folders.
The prospective tester takes their turn.
  1. Tester picks up the iOS device on which they want to test.
  2. On that iOS device tester receives email from TestFlightApp.com, with subject line: "Basil Bourque has invited you to join…".
  3. Tester clicks big green "Accept" button.
    I'm not sure exactly what happens next. I think the button opens a web page to the TestFlightApp.com site which then tries to open a URL for their iOS app called "TestFlight". The user does not have such an app, so the App Store appears with an offer to purchase this app at no cost. 
  4. User proceeds with purchase of "TestFlight" app.
  5. App opens and prompts user to create a personal account on TestFlight, with the user providing their email and inventing a password.
  6. During this process, TestFlight logs this particular device's unique identifier with the TestFlightApp.com web site.
After the user has their device’ identifier logged, TestFlightApp.com sends me an email with Subject line: "So-And-So accepted your invitation". The message includes the device’s identifier. 

Register Device Identifiers

A later goal is building a fresh "Provisioning Profile". To that we must register with Apple a lilt of device identifiers to be authorized to run our app. Our new user's device identifier must be added to our list registered with Apple.

The email mentioned above contains that identifier.

If you lose that email providing the identifier, or you want to look up some other testers’ device identifiers, use the TestFlightApp.com website. Click the main tab for "People". Select the checkboxes of those testers with device(s) that Apple has not yet been made aware. Over in the upper-right of the TestFlightApp.com web page find the grey "Actions" pop-up menu. Choose the menu item "Export iOS devices". Your web browser then downloads a plain text file of the identifiers of the devices owned by those checkmarked testers.

At this point, I need to let Apple know this device(s) is going to be added to my list of authorized testing devices. Remember that Apple limits that list to 100, revised per annum.
  1. I log into http://developer.apple.com.
  2. Click the "Member Center" area of Apple's Developer site.
  3. In the "Developer Program Resources" group box, click the link labeled "Certificates, Identifiers & Profiles – Manage your certificates, App IDs, devices, and provisioning profiles".
    The next page appears with a group box "Certificates, Identifiers & Profiles".
  4. Click "Devices" link. In the side-bar, you should have "Devices" > "All" selected.
  5. I use the web browser's text search feature ("Edit" > "Find" in Safari) to see if the desired device identifier is in the list or not.
  6. Click the "+" button in upper-right to add the identifier. Copy-paste values from the email (or the plain text file as mentioned above). TIP: Include a description of the particular device as part of the tester's name to differentiate when they own multiple devices, such as "Jane Doe – iPad Air".
As a shortcut to manually entering each of several user name + device identifiers, you can import a plain text file such as the one you downloaded early in this page. The catch is that the entire file is rejected if it contains even a single device identifier already registered. I often find it easier to do one at a time.

Provisioning Profile

Now it is time to build that fresh "Provisioning Profile". This encrypted security document lists our registered devices identifiers Apple is granting permission to run my app without that app being delivered through the App Store. This Provisioning Profile will eventually be integrated into a future build of my app intended for distribution to testers.

To create a fresh Provisioning Profile, use that same "Certificates, Identifiers & Profiles" group box page at the Apple Developer site. 

  1. In the side bar, choose "iOS Apps" > "Provisioning Profiles" > "Distribution". 
  2. Select the "Distribution" > "Ad Hoc" radio button.
  3. Follow the Wizard-like steps.
  4. On the step for "Select devices.", click the checkbox labeled "Select All" and continue.
  5. On the step for "Name this profile and generate.", enter a name similar to "Ad Hoc test distrib 2014-11-01".
  6. On that same step, click the "Generate" button.
  7. On a following step, click the "Download" button to download the newly generated Provisioning Profile to your local Mac.
    That file will be named something like "Ad_Hoc_test_distrib_20141101.mobileprovision".
  8. Locate that local file on your Mac.
  9. Open your app’s project in Xcode.
  10. Double-click on the .mobileprovision file causing it to be opened by Xcode.
Now I rebuild the project to incorporate that fresh Provisioning Profile. I am using Xcode 5 (not 6).
  1. Hold down the OPTION key while choosing the menu item "Product" > "Clean Build Folder" and confirm.
  2. Set the "Active Scheme" pop-up in far upper-left corner to "iOS Device".
  3. Choose menu item "Product" > "Archive".
    The Organizer window appears.
  4. In the Organizer, click "Distribute" button.
  5. In Wizard-like window, choose radio button for "Save for Enterprise or Ad Hoc Distribution" (Ad Hoc is what I'm doing).
  6. IMPORTANT – In next step of the Wizard, "Choose a profile to sign with", change the "Provisioning Profile" pop-up menu to your fresh one rather the default old one you used previously. This pop-up is why we named the .mobileprovision file with a date and the words "Ad Hoc", to make selection easier here.
  7. Click "Export" button.
    Wait a couple minutes for a Save As dialog to appear suggesting a ".ipa" file name extension.
  8. In that Export save dialog, I create a new folder named with the date and purpose. Save into that staging folder.
Done with the build process. Now it is time to upload to TestFlight for distribution to our users.

Upload To TestFlight
  1. Login to TestFlightApp.com.
  2. Click the main tab for "Dashboard".
  3. Click the first large green button, "Upload a Build".
  4. In the page that appears, write your Release Notes, indicating a focus for your testers’ work.
  5. Drag-and-drop the .ipa file from your staging folder to the dashed-line box on the same web page, and click green "Upload" button.
  6. Wait patiently for your app to upload.