## Some perceivable inconsistencies, about whether the embedded worksheets can be viewed.

One of the facts which I did mention in an earlier posting, concern worksheets which I sometimes embedded into my postings as ‘<iframe>s’. In reality, there could be two reasons, why such worksheets fail to display in any one person’s browser:

1. I could have embedded them, specifying (insecure) URLs that begin with ‘http://’, even though the reader may be visiting my blog, using a (secure) URL that begins with ‘httpS://’. Or,
2. The posting might suggest that the reader “may need to” enable JavaScript from the domain ‘mathjax.org’, but, in certain cases this is not needed, while in other cases, it is.

‘Problem 1′ above is harder for the reader to fix at their end. It can be solved by fetching my posting using the insecure ‘http://’ URL, or, as I’ve done in a very recent posting, I could decide to embed the ‘<iframe>’ using a URL, which does not specify my domain-name, and just assumes that it’s to be the same, as the domain-name of my site.

‘Problem 2′ above represents a contradiction which may confuse some readers. Sometimes, when I generated an HTML version of a worksheet, I did this by simply clicking on a button, in the GUI of my software. In such cases, the HTML will require that the JavaScript be enabled. But, in certain other cases, all I really did was, to output the worksheet as a LaTeX document, and then to run a custom script on it, to generate other types of documents, one of which would have been an HTML document.

If I ran my custom script on some generic LaTeX document, that generates ‘HTML with equations’, it will do so in the form of ‘a hybrid document’. The resulting document is hybrid, because it can then be viewed in one of two ways:

1. Using the built-in support for ‘MathML’, that some readers’ browsers have. This is less likely, because I only know of one browser that actually support it: ‘Firefox’. If the reader is using ‘MS Edge’ or the ‘Chrome’ browser to view my posting, I know that they do not support MathML as a built-in feature. But,
2. Such a hybrid HTML document can also be viewed, by enabling the JavaScript that gets referred to as ‘MathJax’, and which essentially allows other browsers, including ‘MS Edge’ and ‘Chrome’, to view the equations.

I try to accommodate as many possible configurations of the readers’ browsers as I can, but the unfortunate reality is, that merely pressing the GUI button within my application, may generate HTML which is highlighted more nicely, but which is not a hybrid HTML document.

Dirk

## An Observation About Chrome OS

There is a list of criticisms I could make about Chrome OS, but which I will simply skip for the moment.

I recently bought a new Chromebook.

I have an important piece of information – and praise – about Chrome OS. Its version of the Chrome Web browser – which is simply referred to as ‘Chrome’ – is capable of doing everything that full, desktop Web browsers can do, including, to install extensions from the Chrome Web store. This differs obviously from what the Chrome browser under Android did, which was only a small fraction of that.

Because of this, it’s unnecessary to install numerous Android apps, that just used to be front-ends of sorts, for services that were already available from Web-sites. Four apps which I did not need to install because I was just able to point Chrome to the relevant site, bookmark each site, and log in, are:

1. Skype
2. Netflix
3. Amazon Prime Video
4. Cineplex Store

And I’m writing this, even though there exist reports that the Android Netflix app runs fine under Chrome OS.

I’m sure my list will grow.

Dirk

## Finally getting my FB Messenger Notifications to be Quiet

One of the plans which I had told my contacts about, was that if they send me SMS messages – i.e. phone-texts – the understanding would be that my phone would shout at me, to implore me to answer at once – therefore, for them to use SMS in an emergency.

OTOH, It can happen that one of my friends might like to chat with me, but without causing me to become a distraction to people around me. My phone should notify me noticeably-to-me, but silently. For that purpose, I still recommend that people use Facebook Messenger.

For some time, it was working that way for me, but at some later time, this had stopped working, in that each time I received a FB Messenger Chat Head, my phone had started to give me an audible notification again, which I had some trouble suppressing, in spite of the improvements that Android 7 brought to my Phone!

However, since recent months, I’ve gotten FB Messenger notifications to behave again, exactly as I want them to. And here is how I fixed the problem:

One of the facts which I had observed about the Google Chrome browser version, which is meant for Linux, was that Google no longer provides a 32-bit version of its binaries. In keeping with this, Google has also removed the section in its code repository, which would make a 32-bit version available. Hence, I can only be subscribing to the 64-bit upgrades. Yet, my Linux computer ‘Phoenix’ has its package manager set up, to query a repository for both the 64-bit and the 32-bit versions of any package by default, and then to download and install the packages which are relevant.

In this earlier posting, I observed how this can lead to an error message when running ‘apt-get update‘. What I had done, was to make minor configuration changes like so, which I had needed to re-apply, after every upgrade to Chrome.

Well Google has caught up with the scenario which I was describing. As of their latest upgrade, their own ‘cron.daily‘ symlink will properly put the following source into ‘/etc/apt/sources.list.d/google-chrome.list‘ :




You may note, that the script from Google now includes the ‘[arch=amd64]‘ parameter, which means that I won’t have to make any manual adjustments to this configuration detail of my machine, every time the Chrome browser receives an upgrade.