Shaun Mccran

My digital playground

23
F
E
B
2010

Creating a pop up floating div with JQuery

This entry will deal with how to create a displayed / collapsible floating div, using JQuery. When I build a web platform I often like to include small sections of text alongside the functionality, just to provide the users with a little guidance on what is going on. Rather than having these inline, where they can often interfere with the content and display, I like to add them to a 'help' div that I float inside the framework. First we include the JQuery library from Google, and our link. It doesn't go anywhere, but we will attach a JQuery event to it.
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1<s/cript type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
2
3<a href="javascript:void(0);" id="help">Pop me up</a>
4<div>stuff</div>
Next we create our JQuery function, attached to the 'help' div. This adds a div to the document with whatever content you have set in it. There is also a 'close' link in the floating div that calls the close function.
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1<s/cript>
2 $(function() {
3 $("#help").live('click', function(event) {
4 $(this).addClass("selected").parent().append('<div class="messagepop pop">Content<p><a class="close" href="/">Cancel</a></p></div>');
5 $(".pop").slideFadeToggle()
6 return false;
7 });
8
9 $(".close").live('click', function() {
10 $(".pop").slideFadeToggle();
11 $("#contact").removeClass("selected");
12 return false;
13 });
14 });
15
16 $.fn.slideFadeToggle = function(easing, callback) {
17 return this.animate({ opacity: 'toggle', height: 'toggle' }, "fast", easing, callback);
18 };
19</script>
Lastly we add some styling and positioning to tie the whole lot together. This gives the pop up div its shape and style. I've positioned the floating div on top of the calling function text.
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1<style>
2a.selected {
3 background-color:#1F75CC;
4 color:white;
5 z-index:100;
6}
7
8.messagepop {
9 background-color:#FFFFFF;
10 border:1px solid #999999;
11 cursor:default;
12 display:none;
13 margin-top: 15px;
14 position:absolute;
15 text-align:left;
16 width:394px;
17 z-index:50;
18 padding: 25px 25px 20px;
19 top: 0px;
20 left: 0px;
21}
22}
23
24label {
25 display: block;
26 margin-bottom: 3px;
27 padding-left: 15px;
28 text-indent: -15px;
29}
30
31.messagepop p, .messagepop.div {
32 border-bottom: 1px solid #EFEFEF;
33 margin: 8px 0;
34 padding-bottom: 8px;
35}
36</style>
You can see an example functionality here.

16
F
E
B
2010

Controlling show() hide() Divs with a JQuery powered Select field

There are many ways of hiding all your page elements then only showing specific areas based on user selection. One old school way of changing the displayed page content was with a select field that had an onchange event that posted to the same page, but with a URL variable.

I have been testing out a variation on this using the JQuery show() / hide() functions.

We attach an event to the select field, and pass the selected option to a JQuery function, as in the example code below.

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1<s/cript type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
2
3<select name="field_data_loc[key]" class="form-select required" id="edit-field-data-loc-key" onChange="showHide(this.value)" >
4<option value="didnotchoose" selected="selected">Choose</option>
5<option value="web">Website</option>
6<option value="file">File to upload</option>
7<option value="url">Url</option>
8</select>

We have a series of DIV's that are named the same as the select field options. All these DIV's will be hidden by default, apart from the "start" div.

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1<div id="start">Starting div</div>
2
3<div id="url">url</div>
4
5<div id= "file">file</div>
6
7<div id= "web">web</div>

Lastly we have our JQuery script. Here we have our showHide function. This accepts a DIV id, which is then shown. All other DIV's are hidden.

The last piece of script here simply hides all the DIV's on the page load, so that they are all hidden by default.

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1<s/cript language="javascript">
2
3    function showHide(obj)
4        {
5            var showDiv = "#"+obj;
6            $("div").hide();
7            $(showDiv).show();
8        }
9
10    // hide all the divs on start up
11    $('#web').hide();
12    $('#file').hide();
13    $('#url').hide();
14
15</script>

Putting it all together, and making it dynamic based on a list, it looks like this:

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1<cfset variables.mylist = "scotland,england,wales,ireland">
2
3<s/cript type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
4
5<cfoutput>
6<select name="field_data_loc[key]" class="form-select required" id="edit-field-data-loc-key" onChange="showHide(this.value)" >
7<option value="didnotchoose" selected="selected">Choose</option>
8
9    <cfloop list="#variables.mylist#" index="variables.index">
10        <option value="#variables.index#">#variables.index#</option>
11    </cfloop>
12
13</select>
14
15<div id="start">Starting div</div>
16
17<cfloop list="#variables.mylist#" index="variables.index">
18    <div id="#variables.index#">#variables.index#</div>
19</cfloop>
20
21<s/cript language="javascript">
22
23    function showHide(obj)
24        {
25            var showDiv = "##"+obj;
26
27            <cfloop list="#variables.mylist#" index="variables.index">
28                $('###variables.index#').hide();
29            </cfloop>
30                $('##start').hide();
31
32            //$("div").hide();
33            $(showDiv).show();
34        }
35
36<cfloop list="#variables.mylist#" index="variables.index">
37    $('###variables.index#').hide();
38</cfloop>
39
40</script>
41</cfoutput>

An example is here.

10
F
E
B
2010

Dynamically editing web content inline, using JavaScript and AJAX

Most of us are familiar with the standard method of displaying data in a tabulated fashion, selecting a record, and populating the form that follows. What about editing the content directly into a template that mirrors the actual live version of a page?

This article examines how to edit web content directly inline, and commit it back to a server using an AJAX post request.

The main catalyst for this is that clients that use a content management system do not often have a clear image of how their content will look online. The traditional form layout for entering text does not lend itself well to representing the actual content in the format it is display in.

The aim here is to build a flexible system that allows for inline content editing, and saves it gracefully to a server based database.

I will start by saying thank you to Peter-Paul Koch. His article here (http://www.quirksmode.org/dom/cms.html) on making content editable was invaluable, and a lot of this is based on his theory.

We start by setting a value "editing" to false. This is the default for the page, as the user isn't editing anything when the page loads.

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1var editing = false;
2
3if (document.getElementById && document.createElement) {
4    var butt = document.createElement('BUTTON');
5    var buttext = document.createTextNode('Save');
6    butt.appendChild(buttext);
7    butt.onclick = saveEdit;
8}
9
10function catchIt(e) {
11    if (editing) return;
12    if (!document.getElementById || !document.createElement) return;
13    if (!e) var obj = window.event.srcElement;
14    else var obj = e.target;
15    while (obj.nodeType != 1) {
16        obj = obj.parentNode;
17    }
18    if (obj.tagName == 'TEXTAREA' || obj.tagName == 'A') return;
19    while (obj.nodeName != 'P' && obj.nodeName != 'HTML') {
20        obj = obj.parentNode;
21    }
22    if (obj.nodeName == 'HTML') return;
23    var x = obj.innerHTML;
24    var y = document.createElement('TEXTAREA');
25    var z = obj.parentNode;
26    z.insertBefore(y,obj);
27    z.insertBefore(butt,obj);
28    z.removeChild(obj);
29    y.value = x;
30    y.focus();
31    editing = true;
32    getId(e)
33}
34
35function getId(e) {
36    var targ;
37    if (!e) var e = window.event;
38    if (e.target) targ = e.target;
39    else if (e.srcElement) targ = e.srcElement;
40    if (targ.nodeType == 3) // defeat Safari bug
41        targ = targ.parentNode;
42    thisTarget = e.target.id;
43    
44}
45
46function saveEdit() {
47    var area = document.getElementsByTagName('TEXTAREA')[0];
48    var y = document.createElement('P');
49    // set the id back to the original value as the real one is destroyed
50    y.setAttribute('id', thisTarget);
51
52    var z = area.parentNode;
53    y.innerHTML = area.value;
54    z.insertBefore(y,area);
55    z.removeChild(area);
56    z.removeChild(document.getElementsByTagName('button')[0]);
57    editing = false;
58    // action the server request, first var is the value, second var is the id
59    saveToServer(y.innerHTML,thisTarget);
60}
61
62function saveToServer(valToCommit,fieldname) {
63    //alert(valToCommit);
64    $.post("view/appeals/act_commitChange.cfm", { newValue: valToCommit, field: fieldname, appeal: intId },
65
66    function(data){
67        alert(data);
68    });
69
70document.onclick = catchIt;

I wont go into massive depth on a line by line basis but Peter's article does break this down a lot. The premise is that there is a function catchit(), which will intercept any click events. It will then check that the event was triggered from a 'P' tag, which is our defining element for editable content. IE any P elements hold editable content. It will then remove the P html container, replacing it with a textarea, and re insert the P tags previous html content using the innerHTML JavaScript function.

In this way we can create editable inline textareas within the framework of our page.

The next step is to create a save function. The function 'saveToServer{)' take several arguments. It needs the value to commit, IE what the amended text string is, and the fieldname. Each 'P' tag has an id that I am matching to a data field. In this way if there are multiple p tags in a display they can each be attributed to a specific storage field in a database.

Because we are destroying the 'P' tag when we create the textarea we need to re assign the id to it when we save. We can do this by using the JavaScript function 'setAttribute'. The setAttribute function is used to set the value of an attribute on an object. It is typically used along with objects returned by document.getElementById to assign a new value to the object's attribute.

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1// set the id back to the original value as the real one is destroyed
2y.setAttribute('id', thisTarget);

If we don't do this then the recreated 'P' tag no longer has an id attribute, so will error on any subsequent updates.

Next we use a JQuery Post function to post the values through an AJAX request.

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1$.post("commitChange.cfc", { newValue: valToCommit, field: fieldname, appeal: intId },

This will post the values to the cfml CFC "commitChange.cfc", which handles them in a function.

This will allow you to perform seamless inline edits to the display layer, and commit them back to a server, so they are stored in real time.

There is an example of this here. (Minus the storing). You can track the AJAX post using a tool like charles http proxy, or firefox's firebug.

Now, to write a nice JQuery response handler to fade the returned massage in and out.

04
F
E
B
2010

NoScript alternatives for Javascript content using CSS visibilty

I recently stumbled upon an interesting dilemma whilst using an image map that was dynamically generated from a Coldfusion Query. If you turn JavaScript off, then the image maps primary graphic still stays visible (and occupies the same space on a page), but none of the map links function anymore. The problem was to replace the map content with a list of hyperlinks that provide the same functionality. Initially I set the maps div CSS to be hidden. In this way the map is not shown by default.
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1// css
2.interactiveMap {visibility: hidden;}
Next we can use a JavaScript call to change the CSS visibility to 'visible'. In this way if JavaScript is disabled the graphic remains hidden, if JavaScript is enabled it turns in on.
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1<s/cript>
2    // show the map
3    document.getElementById('interactiveMap').style.visibility = "visible";
4</s/cript>
Lastly we can create the content that we want to see instead of the map. Don't forget to wrap it all in the no script html tag.
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1<noscript>Your browser does not support JavaScript!
2<p></p>
3
4<!--- get the regions list --->
5<cfset variables.regions = getRegions()>
6
7<ul>
8<cfloop query="variables.regions">
9<li><a href="region.cfm?region=#variables.regions. regionid#">#variables.regionName#</a></li>
10</cfloop>
11
12</ul>
13</noscript>
By altering the css properties like this we can have the map and the no script content occupy the same real estate on the screen. If you simply populate the no script with the alternative, then the space the map occupies stays occupied, just by a hidden map, giving you a large blank space.

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