RT #52662: Fix requirement specification for XML::LibXML.
A preponderance of Perl, an excess of XML, and additional alliterations.
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RT #52662: Fix requirement specification for XML::LibXML.
Today, a short one as I’m short on time. But I wasn’t able to do a PMM last week, and I’d hate to skip it two weeks in a row, so…
Say hello to File::Tail. A simple concept, but a very, very useful one. Ever run the *NIX “tail -f <file>” command? Yeah, it’s pretty much just like that. Only in Perl, so it’s actually more flexible. Much more.
You can use it in a very simple manner, to read from files that are continuously updating. You can control how often and to what degree it adjusts the wait-interval it uses when polling the underlying file to check for changes. You can also tie a file-handle to it. You can do things like select-polling across several such handles or objects, to read in a non-blocking way from multiple tail’d files at once. It even comes bundled with two sample scripts showing it in action.
Check it out!Tags: CPAN, module-monday, Perl
RT #49406: Make Base64 data-type allow zero-length data.
RT #50013: Restore backwards-compatibility for projects that use RPC::XML::Parser directly.
RT #50143: Incorrectly called server_fault() as if it were a coderef.
Perl seems to always lead the language-pack in terms of Advent Calendars each year. Here are a few that I know of, that I’m following daily:
Go forth and, errr, advent…Tags: Perl
I’ve been interested in the Chart::Clicker package for a while, and today it came up in a series of Twitter messages in my #perl search. So that seemed like a sign that it would be a good pick for this week’s feature.
Chart::Clicker is a mature, very feature-rich charting package that comes with a cookbook and many examples (the code for the examples is available on GitHub). There’s also a tutorial POD in the distribution. It does pie charts, line graphs, bar graphs, area graphs, stacked bar or area or line graphs, points, bubbles, or candlestick-style charts. In short, it makes pretty pictures in Perl:
The above is just one of the images shown as examples of what Chart::Clicker can do.
The module bases its rendering on Graphics::Primitive, specifically Graphics::Primitive::Driver::Cairo. This means it can render the chart in any format Cairo supports; PNG, PDF, even SVG among others. The internal object-model is based on Moose, which leads to keeping potentially-duplicate code to a minimum. Using the package is about as complex as you need your graph to be: a simple graph with a single set of data can be created in just 5 lines of code or so, while some of the examples are much more complicated scripts.
I’m surprised to see (according to CPANTS) that this module is not a component in any other packages’ lists of dependencies. It would seem to me to be a logical bit of functionality to integrate into a Catalyst view, or any stats package. I won’t be surprised if this changes in the near future, as (hopefully) more people start using the package.Tags: CPAN, module-monday, Perl
It looks as though I have some “competition” for my CPAN Twitter bot (@cpan_linked). The last few days I’ve been seeing posts from @cpanlive in my Perl search-column (I use Seesmic Desktop, with a permanent column for searches on “#perl“). This seems to be pretty much identical in intent to my bot, with some differences. I’ll cover those and what I think of them:
Where I do URL-shortening (currently through TinyURL due to some down-time with Metamark, though I think they’re back up now), @cpanlive doesn’t. I believe that if the status message were to exceed 140 characters, Twitter would notice this and scan the message for URLs to shorten automatically. In the end, I suppose it’s a matter of taste– with @cpanlive you’ll see the actual URL the majority of the time.
I usually provide two links, the second being to the “Changes” (Changes, ChangeLog, etc.) file, or the README if I can’t find a change-log. @cpanlive provides just the main link. I also include the author’s name. This goes back to the use of URL-shortening– I’m careful to keep my status under 140 characters, but having pre-shortened the links gives me more room to play with.
I don’t use any hash-tags, currently. @cpanlive uses both “#Perl” and “#CPAN”. On the one hand, I probably wouldn’t have even known about this if it weren’t for the tagging, as I wouldn’t have seen it otherwise. On the other hand, this puts a lot of data from a single bot into the #perl search-stream. Most people know to follow a given bot if they want CPAN stream updates, and would prefer to not have them cluttering up #perl.
That said, I am considering adding #CPAN to the updates that @cpan_linked puts out, as well as the re-write that I’m (slowly) working on. I think that such data is more useful to users searching on #CPAN than those searching on #Perl.
When @cpan_linked gets a cluster of several CPAN updates at once, it tries to spread them out over the next period between polls of search.cpan.org‘s RDF feed. Currently, I poll it every 15 minutes, so if I get 5 new items to post they get posted roughly 3 minutes apart. It looks like @cpanlive doesn’t do anything like this, as the updates seem be in “clumps”, which is what I was trying to avoid. Again, a matter of taste. I didn’t want the bot to suddenly spew 10-20 updates into my Twitter stream, pushing everything else “below the fold” as it were. Other followers might not care one way or the other.
Something I’ve noticed, though, is that @cpanlive seems to be about an hour or so behind @cpan_linked, on average. I assume that they’re polling the RDF source hourly, rather than the 15-minute interval I use.
Well, there’s no “conclusion” here, really. I mean, it’s not like I have an exclusive license to relay CPAN releases to Twitter. If such an exclusive right existed, it wouldn’t be mine in the first place! I do wonder about the reason for doing it over again, though it may just be someone’s project for learning how to use the Net::Twitter modules. It does push me to get cracking on my re-write, though, as I have other features planned that should make it even more useful.Tags: CPAN, Perl, Twitter
What I like most about this is that it scratches a particular itch I often have when writing long-lived DB code: I get tired of always pinging the database through the handle, to make sure the connection is still there before attempting any new operation. On this point alone, DBIx::Connector is worth installing.
Fortunately, that wasn’t the only itch he was scratching, when he wrote it, so it does a lot more than just simplify persistent connections. It’s fork- and thread-safe, handles transactions and save-points (nested, no less), and does it all while letting you choose when/if the database gets pinged, and what happens when the connection is no longer active.CPAN, databases, module-monday, Perl
For a while now, I have been having some health problems that have spilled over into my professional life. More to the point, a variety of issues ranging from thyroid to others have made it very hard to sleep well and killed a lot of my ability to concentrate. To make matters worse, some of the medications I take for these problems have been compounding the other problems.
I need desperately to break out of this cycle, and get myself back on track. It’s affecting $DAY_JOB, as well, and I happen to be rather fond of the current job and I’m not in any hurry to be moving on to things new.Tags: meta, Perl
While I am a devout and enthusiastic Perl proponent, there are things that I wish Perl had, or had done differently. One of these is the lack of a clearly-defined exception framework. It’s one of the (very) few things I think Java does better than Perl. Over the years, CPAN has been host to several variations on try/catch-style syntactic sugar. But I now have a favorite: Try::Tiny.
While I had noticed the module scroll by the CPAN Twitter feed, I hadn’t paid much attention to it at first. I like the idea of clean try/catch, but I haven’t used it in any of my modules because I didn’t want to make the lists of dependencies any longer than they have to be. TryCatch, for example, uses Moose, which is a lot to install simply to have a clean exception model.
Then I read this blog post about it, and became much more interested. First off, Tatsuhiko was showing a lot of enthusiasm for something for something that isn’t Plack or PSGI (just teasing!). But mostly, it was just the relief of having a nice try/catch pair with no dependencies.
Let me say that part again, just in case you’re skimming: NO DEPENDENCIES.
Well, aside from Test::More at build-time, but you have that lying around already, right?
This one is absolutely going into the toolbox for future use. I’m also going to look for places where it seems to be an especially-good fit with other modules. (More on that, later.)
Try::Tiny. Give it a, errrr, try…Tags: CPAN, module-monday, Perl