Tags: php

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Monday, October 21st, 2019

Indy web

It was Indie Web Camp Brighton on the weekend. After a day of thought-provoking discussions, I thoroughly enjoyed spending the second day tinkering on my website.

For a while now, I’ve wanted to add maps to my monthly archive pages (to accompany the calendar heatmaps I added at a previous Indie Web Camp). Whenever I post anything to my site—a blog post, a note, a link—it’s timestamped and geotagged. I thought it would be fun to expose that in a glanceable way. A map seems like the right medium for that, but I wanted to avoid the obvious route of dropping a load of pins on a map. Instead I was looking for something more like the maps in Indiana Jones films—a line drawn from place to place to show the movement over time.

I talked to Aaron about this and his advice was that a client-side JavaScript embedded map would be the easiest option. But that seemed like overkill to me. This map didn’t need to be pannable or zoomable; just glanceable. So I decided to see if how far I could get with a static map. I timeboxed two hours for it.

After two hours, I admitted defeat.

I was able to find the kind of static maps I wanted from Mapbox—I’m already using them for my check-ins. I could even add a polyline, which is exactly what I wanted. But instead of passing latitude and longitude co-ordinates for the points on the polyline, the docs explain that I needed to provide …cur ominous thunder and lightning… The Encoded Polyline Algorithm Format.

Go to that link. I’ll wait.

Did you read through the eleven steps of instructions? Did you also think it was a piss take?

  1. Take the initial signed value.
  2. Multiply it by 1e5.
  3. Convert that decimal value to binary.
  4. Left-shift the binary value one bit.
  5. If the original decimal value is negative, invert this encoding.
  6. Break the binary value out into 5-bit chunks.
  7. Place the 5-bit chunks into reverse order.
  8. OR each value with 0x20 if another bit chunk follows.
  9. Convert each value to decimal.
  10. Add 63 to each value.
  11. Convert each value to its ASCII equivalent.

This was way beyond my brain’s pay grade. But surely someone else had written the code I needed? I did some Duck Duck Going and found a piece of PHP code to do the encoding. It didn’t work. I Ducked Ducked and Went some more. I found a different piece of PHP code. That didn’t work either.

At this point, my allotted time was up. If I wanted to have something to demo by the end of the day, I needed to switch gears. So I did.

I used Leaflet.js to create the maps I wanted using client-side JavaScript. Here’s the JavaScript code I wrote.

It waits until the page has finished loading, then it searches for any instances of the h-geo microformat (a way of encoding latitude and longitude coordinates in HTML). If there are three or more, it generates a script element to pull in the Leaflet library, and a corresponding style element. Then it draws the map with the polyline on it. I ended up using Stamen’s beautiful watercolour map tiles.

Had some fun at Indie Web Camp Brighton on the weekend messing around with @Stamen’s lovely watercolour map tiles. (I was trying to create Indiana Jones style travel maps for my site …a different kind of Indy web.)

That’s what I demoed at the end of the day.

But I wasn’t happy with it.

Sure, it looked good, but displaying the map required requests for a script, a style sheet, and multiple map tiles. I made sure that it didn’t hold up the loading of the rest of the page, but it still felt wasteful.

So after Indie Web Camp, I went back to investigate static maps again. This time I did finally manage to find some PHP code for encoding lat/lon coordinates into a polyline that worked. Finally I was able to construct URLs for a static map image that displays a line connecting multiple points with a line.

I’ve put this maps on any of the archive pages that also have calendar heat maps. Some examples:

If you go back much further than that, the maps start to trail off. That’s because I wasn’t geotagging everything from the start.

I’m pretty happy with the final results. It’s certainly far more responsible from a performance point of view. Oh, and I’ve also got the maps inside a picture element so that I can swap out the tiles if you switch to dark mode.

It’s a shame that I can’t use the lovely Stamen watercolour tiles for these static maps though.

Monday, June 24th, 2019

Am I cached or not?

When I was writing about the lie-fi strategy I’ve added to adactio.com, I finished with this thought:

What I’d really like is some way to know—on the client side—whether or not the currently-loaded page came from a cache or from a network. Then I could add some kind of interface element that says, “Hey, this page might be stale—click here if you want to check for a fresher version.”

Trys heard my plea, and came up with a very clever technique to alter the HTML of a page when it’s put into a cache.

It’s a function that reads the response body stream in, returning a new stream. Whilst reading the stream, it searches for the character codes that make up: <html. If it finds them, it tacks on a data-cached attribute.

Nice!

But then I was discussing this issue with Tantek and Aaron late one night after Indie Web Camp Düsseldorf. I realised that I might have another potential solution that doesn’t involve the service worker at all.

Caveat: this will only work for pages that have some kind of server-side generation. This won’t work for static sites.

In my case, pages are generated by PHP. I’m not doing a database lookup every time you request a page—I’ve got a server-side cache of posts, for example—but there is a little bit of assembly done for every request: get the header from here; get the main content from over there; get the footer; put them all together into a single page and serve that up.

This means I can add a timestamp to the page (using PHP). I can mark the moment that it was served up. Then I can use JavaScript on the client side to compare that timestamp to the current time.

I’ve published the code as a gist.

In a script element on each page, I have this bit of coducken:

var serverTimestamp = <?php echo time(); ?>;

Now the JavaScript variable serverTimestamp holds the timestamp that the page was generated. When the page is put in the cache, this won’t change. This number should be the number of seconds since January 1st, 1970 in the UTC timezone (that’s what my server’s timezone is set to).

Starting with JavaScript’s Date object, I use a caravan of methods like toUTCString() and getTime() to end up with a variable called clientTimestamp. This will give the current number of seconds since January 1st, 1970, regardless of whether the page is coming from the server or from the cache.

var localDate = new Date();
var localUTCString = localDate.toUTCString();
var UTCDate = new Date(localUTCString);
var clientTimestamp = UTCDate.getTime() / 1000;

Then I compare the two and see if there’s a discrepency greater than five minutes:

if (clientTimestamp - serverTimestamp > (60 * 5))

If there is, then I inject some markup into the page, telling the reader that this page might be stale:

document.querySelector('main').insertAdjacentHTML('afterbegin',`
  <p class="feedback">
    <button onclick="this.parentNode.remove()">dismiss</button>
    This page might be out of date. You can try <a href="javascript:window.location=window.location.href">refreshing</a>.
  </p>
`);

The reader has the option to refresh the page or dismiss the message.

This page might be out of date. You can try refreshing.

It’s not foolproof by any means. If the visitor’s computer has their clock set weirdly, then the comparison might return a false positive every time. Still, I thought that using UTC might be a safer bet.

All in all, I think this is a pretty good method for detecting if a page is being served from a cache. Remember, the goal here is not to determine if the user is offline—for that, there’s navigator.onLine.

The upshot is this: if you visit my site with a crappy internet connection (lie-fi), then after three seconds you may be served with a cached version of the page you’re requesting (if you visited that page previously). If that happens, you’ll now also be presented with a little message telling you that the page isn’t fresh. Then it’s up to you whether you want to have another go.

I like the way that this puts control back into the hands of the user.

Saturday, March 9th, 2019

Updating email addresses with Mailchimp’s API

I’ve been using Mailchimp for years now to send out a weekly newsletter from The Session. But I never visit the Mailchimp website. Instead, I use the API to create a campaign each week, and then send it out. I also use the API whenever a member of The Session updates their email preferences (or changes their details).

I got an email from Mailchimp that their old API was being deprecated and I’d need to update to their more recent one. The code I was using had been happily running for about seven years, but now I’d have to change it.

Luckily, Drew has written a really handy Mailchimp API wrapper for PHP, the language that The Session’s codebase is in. Thanks, Drew! I downloaded that wrapper and updated my code accordingly.

Everything went pretty smoothly. I was able to create campaigns, send campaigns, add new subscribers, and delete subscribers. But I ran into an issue when I wanted to update someone’s email address (on The Session, you can edit your details at any time, including your email address).

Here’s the set up:

use \DrewM\MailChimp\MailChimp;
$MailChimp = new MailChimp('abc123abc123abc123abc123abc123-us1');
$list_id = 'b1234346';
$subscriber_hash = $MailChimp -> subscriberHash('currentemail@example.com');
$endpoint = 'lists/'.$listID.'/members/'.$subscriber_hash;

Now to update details, according to the API, I can use the patch method on that endpoint:

$MailChimp -> patch($endpoint, [
    'email_address' => 'newemail@example.com'
]);

But that doesn’t work. Mailchimp effectively treats email addresses as unique IDs for subscribers. So the only way to change someone’s email address appears to be to delete them, and then subscribe them fresh with the new email address:

$MailChimp -> delete($endpoint);
$newendpoint = 'lists/'.$listID.'/members';
$MailChimp -> post($newendpoint, [
    'email_address' => 'newemail@example.com',
    'status' => 'subscribed'
]);

That’s somewhat annoying, as the previous version of the API allowed email addresses to be updated, but this workaround isn’t too arduous.

Anyway, I figured it share this just in case it was useful for anyone else migrating to the newer API.

Update: Belay that. Turns out that you can update email addresses, but you have to be sure to include the status value:

$MailChimp -> patch($endpoint, [
    'email_address' => 'newemail@example.com',
    'status' => 'subscribed'
]);

Okay, that’s a lot more straightforward. Ignore everything I said.

Sunday, November 25th, 2018

Quick Note: Setting up a localhost on a Mac | scottohara.me

Okay, I knew about the Python shortcut—I mentioned it in Going Offline—but I had no idea it was so easy to do the same thing for PHP. This is a bit of a revelation for me!

Once in the desired directory, run:

php -S localhost:2222

Now you can go to “localhost:2222” in your browser, and if you have an index.html or .php file in your root directory, you’re in business.

Tuesday, September 26th, 2017

Essential Vanilla JavaScript Functions

The title is overkill, but these functions ported from PHP to JavaScript could be useful (especially for dealing with arrays).

Tuesday, August 22nd, 2017

A few technical words about Upsideclown, and some thoughts about audiences and the web (17 Aug., 2017, at Interconnected)

Matt writes about the pleasure of independent publishing on the web today:

It feels transgressive to have a website in 2017. Something about having a domain name and about coding HTML which is against the grain now. It’s something big companies do, not small groups. We’re supposed to put our content on Facebook or Medium, or keep our publishing to an email newsletter. But a website?

But he points out a tension between the longevity that you get from hosting the canonical content yourself, and the lack of unified analytics when you syndicate that content elsewhere.

There’s no simple online tool that lets me add up how many people have read a particular story on Upsideclown via the website, the RSS feed, and the email newsletter. Why not? If I add syndication to Facebook, Google, and Apple, I’m even more at sea.

Thursday, January 19th, 2017

bastianallgeier/letter: Letter is a simple, highly customizable tool to create letters in your browser.

A nice little use of print (and screen) styles from Bastian—compose letters in a web browser.

Instead of messing around in Word, Pages or even Indesign, you can write your letters in the browser, export them as HTML or PDF (via Apple Preview).

Tuesday, January 12th, 2016

VerbalExpressions/JSVerbalExpressions

Regular expressions are my kryptonite so I can definitely imagine using the PHP port of this plain English syntax.

Sunday, June 28th, 2015

100 words 098

When I’m grilling outside, I cook on a gas barbecue. There are quite a few people who would take issue with this. Charcoal is clearly better, they claim. And they’re right. But the thing is, I can fire up my gas barbecue quickly and just get down to cooking.

When I’m programming on the server, I code in PHP. There are quite a few people who would take issue with this. Any other language is clearly better, they claim. And they’re right. But the thing is, I can fire up my text editor quickly and just get down to coding.

Saturday, June 13th, 2015

PHP is the right tool for the job (for all the wrong reasons) - Sam says you should read this

I think there’s a lot of truth to this. By any objective measurement, PHP is clearly inferior to just about every other programming language out there …but its preinstalled out-of-the-box nature means it’s the path of least resistance.

Friday, December 12th, 2014

bramus/mixed-content-scan

A really handy command-line tool that scans your site for mixed content — very useful if you’re making the switch from http to https.

Sunday, October 20th, 2013

Unfashionably profitable

Rachel talks about some of the old-fashioned technologies and business practices driving Perch.

This reminds of a talk by Marco Arment at Webstock a few years back when he described the advantages of not using cutting-edge technologies: most of the time, “boring” well-established technologies are simply more stable.

Tuesday, June 4th, 2013

Craft a better web.

A new PHP-based content management system. It uses Twig for the templating, which I like.

Saturday, November 19th, 2011

Pattern primer

I’m on a workshopping roll. Fresh from running my Responsive Enhancement workshop in Belfast, I’m now heading to Düsseldorf for Beyond Tellerand where I’ll be running the workshop on Sunday (and if you can’t make it, don’t forget that you can book the workshop for your own workplace too).

As part of the process of building a responsive site from the content out rather than the canvas in, I talk about beginning with the individual components divorced from any layout context. Or, as Mark puts it, “start with the bits.”

That’s the way I’ve been starting most of my projects lately: beginning with the atomic units of content and styling them first before even thinking about layout. This ensures that those styles are extremely robust—because they don’t depend on any particular context, they can be safely dropped into any part of a page.

I’ve been calling this initial collection of markup snippets a pattern primer. To help create the pattern primer, I’ve written a little bit of PHP to automatically generate a page of patterns from a folder of HTML snippets.

In my workshop I keep promising to put that script on Github. I finally got around to doing that and you can find it at github.com/adactio/Pattern-Primer.

Take a look at an example pattern primer to get an idea of what a handy deliverable this can be if you’re handing off to other developers. It also acts like a page of unit tests for CSS—whenever you’ve been messing around in the stylesheet you can refresh the page to quickly check to see if anything looks screwed up.

Grab the code; improve upon it; share your changes.

Thursday, August 25th, 2011

Responsive HTML images

If you’re trying to retrofit an existing desktop-centric site for small screens, this server-side image-resizing technique might be useful but is definitely not the right tool for a content-out, small-screen-first approach.

Thursday, June 23rd, 2011

Markdownify: The HTML to Markdown converter for PHP

This could be handy for the editing process in my home-grown blogging system: a PHP script to convert HTML back to Markdown.

Friday, August 21st, 2009

Amazon® AWS HMAC signed request using PHP

Since Amazon decided to require signed requests for its API, I'm going to have to use this code to keep Huffduffer and The Session working. Grrrr... cool APIs don't change.

Saturday, August 1st, 2009

Let's make the web faster - Google Code

A whole heap of optimisation techniques from Google for faster CSS, JavaScript, markup and PHP.

Monday, July 6th, 2009

PHP Typography 1.0 beta 3 • KINGdesk

A PHP script that adds nice typography to your markup.

Tuesday, June 30th, 2009

PHP: goto - Manual

Wait... I thought this was considered harmful?