PHP/Javascript Asynchronous Lighthouses in Australia Tutorial

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PHP/Javascript Asynchronous Lighthouses in Australia Tutorial

PHP/Javascript Asynchronous Lighthouses in Australia Tutorial

Today we want to try two things …

  1. continuing on with our PHP code (you could call australian_lighthouses.php) for our Australian Lighthouses project
  2. talk about Javascript asynchronous script tag option

… so let’s talk about the second one first … it’s south … chortle, chortle.

Why should you be interested in the HTML’s script tag attributes …

  • asynch=”asynch”
  • defer=”defer”

? Well, we want our web pages to load as fast as possible. Yaaaaaa?! So if there was the mechanism to do more than one bit of ((client) Javascript) thinking at a time would you avail yourself of the opportunity … or would you pick what’s behind door 3?

Do you want to hear more on this theory wise? It seems to me, there are web application mission critical parts, and there are embellishments, quite often … “nice to haves” but not “mission critical” … well, if those “nice to haves” could be arranged not to hog all the web application designated CPU that would be good, wouldn’t it?! Yaaaaaaaaaaa?!

So, that, in theory, is y why.

Now back to the project at hand … Australian Lighthouses … don’t you think some geographical sorting options and place name sorting options might be useful? Yaaaaaaaaaaaaaaaaa?! But for us it doesn’t feel mission critical … so we …

  • place the logic in some external Javascript called australian_lighthouses.js
  • we load it from the PHP via
    <script type=”text/javascript” src=”australian_lighthouses.js” async=”async”></script>

    … and this amounts to the only change to today’s PHP code from yesterday as per this link

… and this becomes a way to modularize your thinking regarding a project … please don’t think there are not a myriad of other ways … this is just one idea here.

With regard to how we approached our external Javascript we did not demand anything (much) of our parent PHP and this may not be the fastest way to approach this. What we mean by that is that, perhaps, as a general rule, external Javascript can perform faster with the parent PHP or HTML leaving it with a lot more HTML element id=”[elementId]” to hang its hats on, so to speak … instead, here, we acted innocently with our Javascript and used lots of calls to the Javascript DOM method getElementsByTagName() (which results in an array return value). Perhaps calls to getElementById() via (parent) arranged id=”[elementId]” would be faster?! Today, as with the previous Static HTML Javascript Primer Tutorial we concentrated on the “modular” feel to additional external Javascript code ideas.

So try a live run to see what we mean.

Previous relevant PHP Lighthouses in Australia Primer Tutorial is shown below.

PHP Lighthouses in Australia Primer Tutorial

PHP Lighthouses in Australia Primer Tutorial

Today we examine some of the methodology behind a project idea.

Projects need …

  • an idea … ours came from listening to the radio and hearing about Lighthouses, and how the technologies had changed what they look like and how they function these days … to quote Wikipedia with respect to Australian Lighthouses (thanks) …

    The first lighthouse was Macquarie Lighthouse, which was lit in 1793 as a tripod mounted wood and coal fired beacon. The last manned lighthouse was Maatsuyker Island Lighthouse, off the south coast of Tasmania, which was automated in 1996.

  • a means to access information … much easier these days with the search engines … we went with a Google Search as per list of lighthouse positions … which led to …
  • the information source(s) … we settled, and were not surprised about the source, for Wikipedia’s List of lighthouses and lightvessels in Australia – Wikipedia … then, once happy about the quality of the source information, analyzed …
  • the source data format … initially, at least, via View->Page Source, relative to the webpage … to get ideas for how to parse the data … so that we can determine a …
  • programming language of choice … which is PHP … no surprise here … will need a server-side language … and a method like PHP’s file_get_contents() … from there …
  • PHP coding to parse the data and put it into another format that value adds … otherwise why do it, as the Wikipedia information is fine as is … that is where we determine that we should …
  • include an iframe that uses the Google Chart Map Chart to add that extra overall positional view of Lighthouses … a definite asset to the reader’s understanding of the subject … definitely a “where” web application … and in doing this we notice that …
  • Google Chart Map Chart map.php web application needed to be able to handle much larger input data streams than it could in its previous incarnation of only allowing PHP $_GET[] parameters … so we change it to allow $_POST[] parameters … maybe you noticed this with yesterday’s PHP/Javascript/HTML Google Chart Map Onclick Tutorial as shown below … as this meant that …
  • we need an HTML form that POSTs to the iframe with the Google Chart Map Chart map.php web application allowable because we are on the same domain with this thinking … and using an HTML textarea element to store the huge string of Lighthouse data that will be passed across via urldecode($_POST[‘data’]) at map.php … using PHP’s urldecode() and urlencode() methods and Javascript’s decodeURIComponent() method … as well as utilizing …
  • Google Chart Map Chart map.php web application onclick and tooltip functionality we’ve been working on lately … hence the talk about this below … working out what (component) tools could do with a “makeover” is an extremely important part of any project and can be a useful compartmentalizing of the project

… and so we end up with our live run behind which is the PHP programming source code you could call australian_lighthouses.php for your perusal.

Previous relevant PHP/Javascript/HTML Google Chart Map Onclick Tutorial is shown below.

PHP/Javascript/HTML Google Chart Map Onclick Tutorial

PHP/Javascript/HTML Google Chart Map Onclick Tutorial

They say “the knee bone’s connected to the thigh bone” then they say “the thigh bone’s connected to the … hip bone” then they say “let’s call the whole thing off” … sometimes.

Today we say “the onmouseover event is connected to the onclick event” then we say “the onclick event is connected to the online woooooorld” … “do … the hokey pokey” x3 … “that’s what the onclick event preceeded by the onmouseover event within the environs you are encountering … is all about”.

That news is pretty good actually, because it means mobile users are not missing out on much not having easy access to any onmouseover (ie. hover) functionality … they’ll still reach any onclick logic you present them, in the default case of events where onclick is a valid “touch” event as well.

So the data structure of arrangements to allow for this onclick functionality is intrinsically the same as allowed for yesterday with the PHP/Javascript/HTML Google Chart Map Tooltips Tutorial as shown below, but we just check for some more delimitation issue matters, and our updated prompting window logic gets quite “blurby” as per the Javascript (via PHP) …



echo " datalinesuffix = prompt('Enter decimal Latitude,Longitude ' + thisline + extra + ' (for no more hit Cancel button and append with ' + '\\n\\n' + ',\"A tooltip and clicking link for Google Map of <a target=_blank href=https://www.google.com.au/maps/place/' + encodeURIComponent(dlp2) + '>' + dlp2 + '</a>\" ' + '\\n\\n' + ' or maybe perhaps ' + '\\n\\n' + ',\"A tooltip and clicking link for Google Map based on latitude and longitude of <a target=_blank href=https://maps.google.com.au/maps?' + encodeURIComponent('z=15&t=m&q=loc:') + '{latitude}{longitude}>' + dlp2 + '</a>\"' + '\\n\\n' + ' optionally (as (just) two examples of what is possible with HTML included (activates with onclick bit not onmouseover))', thisdef); " . "\n";
echo ' if (datalinesuffix != null) { if (datalinesuffix.indexOf("{latitude}") != -1) { dlsa=datalinesuffix.split(","); if (dlsa[0].indexOf("-") == -1) { datalinesuffix=datalinesuffix.replace("{latitude}",encodeURIComponent("+" + dlsa[0])); } else { datalinesuffix=datalinesuffix.replace("{latitude}",encodeURIComponent(dlsa[0])); } } if (datalinesuffix.indexOf("{longitude}") != -1) { dlsa=datalinesuffix.split(","); if (dlsa.length > 1) { if (dlsa[1].indexOf("-") == -1) { datalinesuffix=datalinesuffix.replace("{longitude}",encodeURIComponent("+" + dlsa[1])); } else { datalinesuffix=datalinesuffix.replace("{longitude}",encodeURIComponent(dlsa[1])); } } } } ' . "\n";

… as again we are making use of $_GET[] parameters coming into the PHP at the server side.

The bigger picture plan for how this helps something else we are trying will become apparent over time … in the fullness of time … at the appropriate juncture of juxtapositions.

Let’s see some PHP code in live action for this tutorial where you define your map characteristics and data.

Link to Google Chart Tools “spiritual home” … via Google.
Link to Google Chart Tools Map information … via Google.
Link to Google Chart tooltips information … via Google.

Link to some downloadable PHP programming code … rename to map.php which changed from yesterday as per this link.

Previous relevant PHP/Javascript/HTML Google Chart Map Tooltips Tutorial is shown below.

PHP/Javascript/HTML Google Chart Map Tooltips Tutorial

PHP/Javascript/HTML Google Chart Map Tooltips Tutorial

Here is a tutorial that is revisiting Google Graphs API, or Google Chart Tools, and its Map functionality, which we first talked about with PHP/Javascript/HTML Google Chart Map Tutorial as shown below. Please read …

Google Chart Tools provide a perfect way to visualize data on your website. From simple line charts to complex hierarchical tree maps, the chart galley provides a large number of well-designed chart types. Populating your data is easy using the provided client- and server-side tools.

Why are we revisiting? Well, we are interested in the interactive side to this wonderful product. We are going to start with a look into “tooltips”. Tooltips are those optional informational features of some webpages that happen when hovering over an HTML element, principally through the filling out of an HTML element’s title global attribute.. Google Charts functionality amounts to the use of Javascript, and, these days, SVG HTML elements, so “tooltips” are very relevant to the “user experience” when using Google Charts. With the Map Chart, the latitude, laongitude set is combined with a title, which can be the default “tooltip” shown, as this is all fine for many usages, but we want to extend it so that that title doesn’t have to be the tooltip.

The integration of this added functionality into the Google Chart Map Chart involves adding an extra “string” column to the data table as per the bold bits of the new Javascript (via PHP) snippet …



if (isset($_GET['value']) && (isset($_GET['tooltip']) || strpos($GETdata, "'") !== false)) {
echo " var data = new google.visualization.DataTable(); /" . "/" . $GETlabel . $GETvalue . " \n";
echo " data.addColumn('number', '" . str_replace("'","",str_replace(",","",str_replace("['","",$GETlabel))) . "'); \n";
echo " data.addColumn('number', " . str_replace(",", "); data.addColumn({'type': 'string', 'role': 'tooltip', 'p': {'html': true}}); data.addColumn('string', ", str_replace("]","",$GETvalue)) . "); \n";
echo " data.addRows([ \n";
echo str_replace("''" . "''", "''", str_replace("~", "'", substr($GETdata,1)));
echo " ]); \n";
} else {

echo ' var data = google.visualization.arrayToDataTable([ ' . "\n";
echo " " . $GETlabel . $GETvalue . " \n";
echo str_replace("''" . "''", "''", str_replace("~", "'", $GETdata));
echo " ]);\n";
}

… making use of $_GET[] parameters coming into the PHP at the server side … you’ll find that Javascript loves to work with PHP as one of those Fred and Ginger relationships of the programming world … you’ll be happier writing Javascript from your PHP too … try it and you’ll see the advantages time and again and again and again … did we leave out one? … and again.

The bigger picture plan for how this helps something else we are trying will hopefully become apparent over time.

Let’s see some PHP code in live action for this tutorial where you define your map characteristics and data.

Link to Google Chart Tools “spiritual home” … via Google.
Link to Google Chart Tools Map information … via Google.
Link to Google Chart tooltips information … via Google.

Link to some downloadable PHP programming code … rename to map.php which changed from the days of Google Charts Emailing Primer Tutorial as per this link.

Previous relevant PHP/Javascript/HTML Google Chart Map Tutorial is shown below.

PHP/Javascript/HTML Google Chart Map Tutorial

PHP/Javascript/HTML Google Chart Map Tutorial

Here is a tutorial that introduces you to Google Graphs API, or Google Chart Tools, and its Map functionality.

Google Chart Tools provide a perfect way to visualize data on your website. From simple line charts to complex hierarchical tree maps, the chart galley provides a large number of well-designed chart types. Populating your data is easy using the provided client- and server-side tools.

Let’s see some PHP code in live action for this tutorial where you define your map characteristics and data.

Link to Google Chart Tools “spiritual home” … via Google.
Link to Google Chart Tools Map information … via Google.

Link to some downloadable PHP programming code … rename to map.php.

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