Switching Active Tabs Programattically: Jquery/Bootstrap

There are lots of different ways to control visibility of different types of web elements.

I’m working on the web front end of what will eventually become an HL7 message inspection tool.

I’ve set it up so that when the user pastes an HL7 message into the textarea on the #omsg pane,  the results will be pasted into the #parsedmsg pane.  I then want the latter pane to become visible.

I set all this up using bootstrap tabs.

The tab controls are anchors wrapped in list elements.  To show what tab is visible, Bootstrap relies on the class “active” to be added to the parent li tag.

I don’t know if I’m having an off day but I couldn’t figure out how to have that happen when I switched visibility programmatically.

The panes would switch visibility just fine, but I naturally wanted the active tab button to be highlighted.

Instead of toggling visibility of various elements,  I decided to write a function using DOM traversal to simulate clicking the desired button.

I’ll go into more detail below, but this is the function itself.

function activeTab(newtabid) {
$('#lpane > ul > li > a[href="'+newtabid+'"]').trigger('click');

The tab controls are contained in a div with the id of “lpane”.  As Bootstrap tabs rely on the href attribute, its easy enough to find which element to click using that particular parameter.

Here is the HTML

<div id="wrapper" class="col-lg-12">
<div id="header" class="col-lg-12">
<h3>HL7 Tool</h3>
<div id="lpane" class="col-lg-12 centered">
<ul class="nav nav-pills " style="text-align:center;">
	<li role="presentation"><a data-toggle="tab" href="#omsg">Original Message</a></li>
	<li role="presentation" id="lpmsg"><a class="btn" data-toggle="tab" href="#pmsg" href="#">Parsed Message</a></li>
	<li role="presentation"><a class="btn" data-toggle="tab" href="#redset" href="#">Redaction Settings</a></li>
	<li role="presentation"><a class="btn" data-toggle="tab" href="#redmsg" href="#">Redacted Message</a></li>
<div id="cpane" class="tab-content col-lg-12">
<div id="omsg" class="tab-pane active">
<label for="#omsg">Original Message</label><textarea id="msg" class="form-control" placeholder="Paste Msg Here"></textarea>
<input type="button" class="btn" value="Parse" id="parsemsg"/><input type="button" class="btn" value="Clear" id="clearomsg" />
<div id="pmsg" class="tab-pane">
<div class="col-md-6" id="parsedmsg"></div>
<div id="redset" class="tab-pane">
<div id="redmsg" class="tab-pane">

and finally…the actual script


 }); //parsemsg
 }); //document ready





CSS Calc Function


Have you ever had a problem getting a div to center?   There are times that for some reason the margin: auto;  just doesn’t work.

Its situations like this that get old timers like me poking around Google where we discover new and cool things.   (the whole having a job, and being expected to produce results thing can make that difficult at times).

This led to the discovery of the calc()  function!

Calc allows you to use math to size elements without having to resort to scripting.

In the example below,  I set up a lightbox div with a width that is 100 pixels less than half the width of the parent div  (calc(50% – 100px);).

In order to center this (because margin:auto wasn’t working for some reason),  I used (calc((100% – (50% – 100px))/2);)


.lightbox {
 width:calc(50% - 100px);
 left: calc((100% - (50% - 100px))/2);
 margin-right: auto;
 border: #110ef3 solid 2px;
 border-radius: 5px;
 background-color: #FFF;


Database Result Set to HTML Table Function in PHP

Hi All;

I’m looking at a situation where I need to have several database tables view-able on a web front end without a lot of time to do it.

I created a quick and dirty function to accomplish this.  I thought others might find it useful.

function resultset2html($tblclass,$tblid,$headers,$resultset,$title = null,$titleclass = null) {

//$tblclass:  The html class for the table
//$tblid:  The html id for the table
//$headers:  An array of column headers
//$resultset:  The resultset from the PDO query
//$title: Optional table title
//$titleclass: Optional table title class
$output = "<table class='$tblclass' id='$tblid'>";   //sets up the output.

//creates a table title if specified
if ($title != null) {
if ($titleclass == null) {
$titleclass = '';
} else {
$titleclass = "class='$titleclass'";
$output .= "<tr $titleclass>";
$colcount = count($headers);
$output .= "<th colspan='$colcount'>".$title."</th>";
$output .= '</tr>';

//header row
$output .= "<tr>";
foreach($headers as $colh) {

$output .= "<th>".$colh."</th>";  //creates header row


$output .= '</tr>';

foreach($resultset as $row) {   //iterates through result set

$output .= '<tr>';

foreach ($row as $line) {  //iterates through each column of result set

$output .= "<td >".$line.'</td>';


$output .= '</tr>';


$output .= '</table>';

return $output;


Here is the code where I retrieve the result set from a PDO connection ($dbh) and send it to the function.

I’m using Bootstrap for most of my formatting.

$sql = "SELECT rsndmsg,odatetime,lresenddt,attempts,discard,discardreason,notes FROM hrm_resends WHERE sent = 0";

$q = $dbh->prepare($sql);

$resends = $q->fetchAll(PDO::FETCH_ASSOC);

$headers = array('Message Id','Original Date/Time','Last Attempt','# attempts','discard','Discard reason','Notes');

$resendtable = resultset2html('table-striped table-bordered', 'resends',$headers, $resends,"Messages Queued for Resend","tbltitle");

This is the non Bootstrap css I levered in:

td,th {

.tbltitle th {
background-color:#0073EA !important;
text-align: center;
font-weight: bold;

and, here is the output!


JQUERY: Handle a click event on an HTML element within another clickable element

Confusing title?

Let me explain:

I’m working on a project that will allow my employer’s senior team a patient census board. (I work for a hospital if the “patient” thing didn’t give it away).

As this project spans 4 different hospitals,  I present the initial data in collapsed tables,  populated by JQuery from an XML document passed from a PHP script.

In order to expand a table,  I allow the user to click the appropriate row.

Yesterday I was asked to add some new functionality that would allow the user to call up a list of patients by clicking on a column within that row.

The information in this column is wrapped in a span for display purposes,  so I hooked onto that.

Of course,  when I click on it,  both the span click event, AND the row click event fire!

I prevent this,  by placing the span click event handler above the row click event handler in the js file AND ending the span click even with return false;

This is how the table structure is set up

<th>header row</th>
<tr class="exoccclick">
<td>Another Thing</td>
<td><span class="pdcold">53</span></td>

And this is the click handling code for both the tr class (exocclick) and the span class (pdcold)


var tbid = $(this).closest('table').attr('id');

console.log('pdcclick ' + tbid);

return false;  //<--don't forget this bit!


//some stuff


As this is internal I can’t link the actual page,  but here’s a screen shot of what the row looks like:

The Pend DC Old column is the span class where I added the click handler

The Pend DC Old column is the span class where I added the click handler (click to enlarge)

JQuery/HTML: Handling events for elements created after initial page load.

My regular readers already know that I add a lot of stuff to my pages programmatically using PHP. Naturally much of this code is added after the initial page load.

I used to defeat this by loading in the scripting with the new elements, but that’s very tedious, and honestly, sloppy.

The issue is that new elements aren’t registered with the Document Object Model (DOM) set up when the page loads.

To get around that you can sort of “pre-register” these elements using JQuery’s .on method.

Here’s the syntax:

$(document).on([event],[selector],function(e) {

//do your stuff here


Here’s a working example from an actual piece of code I’m working on.

In this example I’m posting data to a php script when the target element (id=”edname_1″) loses focus, provided it doesn’t match what’s there already. I do this by loading the contents of the control into txtval on the focusin event.

var txtval = '';    //global variable.
		    	txtval = $(this).val();   //loads global
					if ($(this).val() == txtval) {
						console.log("doing nothing");
					if($(this).val().length < 1) {
						alert("This shouldn't be blank");
				$.post('PHP/updateftable.php', {field: $("#activefld").val(), val: $(this).val()}) 
                                         In order to avoid having to add the db table primary key of the row I want to update to every element I add to the div,                         
                                         I created a hidden field and placed that key as the value.

					console.log(data);   //checks the output.

This example is from a piece of actual code for a project in development, so there’s some exception handling, etc. I haven’t done yet.

JQuery: Add Rows and Columns to Tables Programmatically

This turned out to be a bit of a bear to search for exactly what I wanted, in such a way that I understood it…so I’m posting here.

The Problem

To create a table which the user could add columns or rows as they required.
New rows must contain the columns added earlier.

There is no requirement to isolate additional columns to specific rows.

The Solution

The example below uses a class selector as there are several tables (also added programmatically).

Adding a column.

		var tid = this.id;
		var bid = tid.replace('sbutc_','stable_');   //This points to the appropriate parent table

                //first, I need to know how many rows there are so I can get the number of columns in the last one (skipping header rows)
                //Note that I point to the tbody object,  if you don't use these,  that should be the table id.

		var rows = document.getElementById(bid).getElementsByTagName("tbody")[0].getElementsByTagName("tr").length;

		var cols = $('#' + bid + ' tr:nth-child(' + rows + ') td').length;   //get's the number of columns in the last row
		console.log('cols: ' + cols);
		$("#" + bid).find('tr').each(function(){                            
                $(this).find('td').eq(cols-1).after('<td>new cell added</td>');      //adds the new cell. 

                You'll note that I subtract 1 from the column count when adding the column.  This is because when pulling the count, it starts with 1, while 
                object indexes always start at 0

This adds the row.

		var tid = this.id;
		var bid = tid.replace('sbutr_','stable_');
		var rows = document.getElementById(bid).getElementsByTagName("tbody")[0].getElementsByTagName("tr").length;
		var cols = $('#' + bid + ' tr:nth-child(' + rows + ') td').length; 
		var apstring = '<tr>';             //sets up the string used in the append statement
		for(var i=1;i<=cols;i++) {        //adds a td element for each row detected above and appends it to the apstring
			apstring += '<td ondrop="drop(event)" ondragover="allowDrop(event)">-</td>';
		apstring += '</tr>';              //very important!
		$('#' + bid + ' > tbody:last').append(apstring);   //append the row to the bottom of the table

I will post a link so you can see it in action when I get a chance (behind a firewall currently).

Set Selected Option when building HTML Select List in PHP

Wow…you know…the hardest thing about this whole exercise was coming up with a title for this post!

As you’ve gathered from previous entries, I build a lot of my HTML pages in PHP scripts.

When you are building a select list (dropdown, pulldown, picklist) from a database, how do you ensure that the user sees the value that’s in the database?

You could do it using a switch case routine and build your options list in it’s entirety for each option, or you could do it this way.

Scenario, you have an ENUM field in your database that you want to give the user the ability to edit. You also think its very handy for the user to know what’s actually in the database, so you have the select element default to the database value.

Short answer:

Use string replace (str_replace) to add the property selected to the appropriate option.

$options = str_replace('value="G"','value="G" selected',$options);

And now for the long version:

A bunch of code that creates a dataset from a database and puts it in $row[]

$row['ftype'] = 'T';      //you can change these to test the code.
$row['fname'] = 'Text';

$options = '<option value="0">Select a Type</option>';
$options .= '<option value="D">Date</option>';
$options .= '<option value="G">Group</option>';
$options .= '<option value="T">Text</option>';

switch ($row['ftype']) {

    case "D": 

        $options .= str_replace('value="D"','value="D" selected',$options);

   case "G":

      $options .= str_replace('value="G"','value="G" selected',$options);

  case "T":

     $options .= str_replace('value="T"','value="T" selected',$options);

     //nothing to do here

$output = '<html>';
$output .= '<body>';
$output .= '<form id="f1" method="post" action="">';
$output .= '<input type="text" id="f1a" name="f1at" value="'.$row['fname'].'"><br>';

$output .= '<select id="f1b" name="f1b">'.$options.'</select>';
$output .= '</form>';    //pro tip:  type this line immediately after typing the <form> line so you don't forget.

$output .= '</body></html>';
echo $output;

Some of you may have noticed that there is a much easier way to do this if things are as straightforward as in the example.
Simply concatenate the value used in the switch case. This will work great, unless you have additional properties or different formatting in the option tag.

 $options .= str_replace('value="'.$row['ftype'].'"','value="'.$row['ftype'].' selected',$options);

Happy coding…