At the end of part 1 of the series, the system could easily handle direct replacement of certain html entities with their wiki markup counterparts.  Unfortunately this was a pretty limited implementation that could only handle those entities that had a direct, symmetrical relationship with html.  In the case of lists, we have to keep track of depth and better cleanup the input text.  We also need to enforce default behavior on the input stream.

Since lists are dependent on dedicated whitespace as part of their markup, we need to clear out all unnecessary white space from the html before processing it.  To do this, we simply replace all whitespace characters with an innocuous single space to remove any extra new lines.

$(textNode).innerHTML = $(textNode).innerHTML.gsub( '\s', '' );

Next we need to cleanup the recursion.  Since we need to know significantly more about the given node to properly assess it.  We can replace the Prototype templates with simple curried function calls and migrate the recursion to the curried methods.

var ConverterTable = {
strong: Converter.curry("'''", null, true),
b:  Converter.curry("'''" , null, true),
em: Converter.curry( "''"  , null, true ),
i:  Converter.curry( "''"  , null, true ),
h1: Converter.curry( '='  , null, false ),
h2: Converter.curry( '=='  , null, false ),
h3: Converter.curry( '==='  , null, false ),
h4: Converter.curry( '===='  , null, false ),
h5: Converter.curry( '====='  , null, false ),
h6: Converter.curry( '======' , null, false ),
ul: Converter.curry('', {li:Converter.curry(['* ', ''], null, false)}, false),
ol: Converter.curry(”, {li:Converter.curry(['# ', ''], null, false)}, false),
p:  Converter.curry(['','\n'], null, false)
};

The parameters passed into the individual rules are
The Markup String or an array of strings for start and end tags
An optional library of child rules.  These rules will be applied to any children of the given node before the default rules are applied.
An indication as to the ‘inline-ability’ of the given tag.  This controls the bracketing of the resulting markup with ‘\n’ characters.

The modified Converter now looks to apply rules in the following order
If the node is marked as a stopping point, no recursion proceeds on the branch.
If any over-ridden child rules exist for the given tag, those rules are applied and a memo is passed on to child nodes to denote the depth of the recursion.
Any default rules are processed as per the earlier versions of the code.  Note.  A prototype template is no longer used in favor of simple string construction.
The node itself is removed from the DOM.

function Converter( markupString, nestedRules, inline, textNode, memo ){

var startString, endString;
inline = inline ? ” : ‘\n’;
memo = memo ? memo : ”;
var children =  textNode.childElements();

if( typeof markupString == ‘object’){
startString = inline + markupString[0];
endString = markupString[1] + inline;
} else {
startString = inline + markupString;
endString = markupString + inline;
}

for( i in children){
if( typeof children[i] != ‘function’){
if( nestedRules && typeof nestedRules[children[i].tagName.toLowerCase()] == ‘function’){
startString =  memo.strip() + startString;
nestedRules[ children[i].tagName.toLowerCase() ]( children[i], startString);
} else if( typeof ConverterTable[children[i].tagName.toLowerCase()] == ‘function’){
ConverterTable[children[i].tagName.toLowerCase() ](children[i]);
} else { Converter( ”, nestedRules, true, children[i]), memo }
}
}
textNode.replace(  startString + textNode.innerHTML + endString  );
}

Wiki’s are amazing and powerful tools, unfortunately their dependence on specialized markup creates a huge barrier to their general adoption in many organizations.  This is a first step at building a wysiwyg editor for wiki markup.  While I will be focussing on the syntax unique to the popular MediaWiki platform, these techniques should be applicable to any wiki system.

The general flow of the converter is as follows:

1. Converter is passed the root node of an html fragment to translate.
2. Converter recurses through each of the child nodes and converts them.
3. Root node tag is replaced with wiki markup.

There’s really only 2 key components involved in this first pass. A converter object and the recursive method.

The Converter Object

The converter object is little more than a collection of name value pairs.  The name corresponds to an html tag.  The value is a Prototype template to use in the direct replacement of the given node. By convention we’ll write all of the tag names for the converter object in lower case.

var Converter = {
strong: new Template("'''#{body}'''"),
b:  new Template("'''#{body}'''"),
em: new Template("''#{body}''"),
i:  new Template("''#{body}''"),
h1: new Template('=#{body}='),
h2: new Template('===#{body}=='),
h3: new Template(’===#{body}===’),
h4: new Template(’====#{body}====’),
h5: new Template(’=====#{body}=====’),
h6: new Template(’======#{body}======’)  }

The Converter Function

The Converter function always performs 2 checks before attempting to convert a given node.  First it ensures that the node is in fact a node and not a stray function from the Prototype enhanced object.  Next it verifies that a converter exists for the tag.  The toLowerCase() on the tagName is necessary due to the inconsistent behavior browsers demonstrate with this attribute.  While all browsers return the variable in all caps for traditional html, they are not reliable about returning lower case values for xhtml markup.

function convertToWiki( textNode ){
//make sure textNode isn't a function on the object
if( typeof textNode != 'function'){

//provide a way to stop execution on select sub trees
if( !textNode.hasClassName( 'stop')){
$(textNode).childElements().each( convertToWiki );
}

//make sure a converter exists for the given tag
if( liteConverter[ textNode.tagName.toLowerCase() ] ){

//replace the text node with a converted version of itself
textNode.replace( liteConverter[textNode.tagName.toLowerCase()]
.evaluate({body:textNode.innerHTML}));
} } }

in Javascript the Good Parts, Douglas Crockford presents a simple method to curry functions.  It’s a great tool that allows you to build functions with arguments predefined in them dynamically.  In his implementation Array.splice & an indirect method declaration is used.  In my version, I use prototype’s enhanced Array object & a direct call to the Function object to the same effect.

Function.curry = function() {
var args = $A(arguments), that = this;
return function() {
return that.apply( null, args.concat(arguments));
};
};

I’ve been using this method for a few months now in both its prototype & jquery forms and find it invaluable, especially when faced with a need to manipulate a large number of similar objects.

37 Signals has recently announced a new open source rich text editor built on protoype.

It’s a unique take on the Rich Text Editor that focuses on developers over the kitchen sink.

WysiHat is a WYSIWYG JavaScript framework that provides an extensible foundation to design your own rich text editor. WysiHat stays out of your way and leaves the UI design to you. Although WysiHat lets you get up and running with a few lines of code, the focus is on letting you customize it.

Check it out here:
 http://github.com/37signals/wysihat/tree/master

And Read the announcement here:
Introducing WysiHat: An eventually better open source WYSIWYG editor

I needed a way to provide my users with a date picker that was automatically provided when a text area received focus.  I was eager to use the excellent YUI calendar as a starting point, but the provided documentation didn’t provide a solid example for this type of implementation.

Dav Glass has provided a solid example of the Calendar tied to a text input. But, his example is highly dependent on the text input having specific ids.  This doesn’t take advantage of YUI’s excellent Selector library really didn’t meet my need for a simple universal solution.

Key Requirements:

1. Progressive Enhancement (No inline javascript)
2. Yui based
3. Universal implementation across all pages in a site.
4. Support for multiple date inputs on a page.

Getting Started:

Source:

Adding it to your page

Integrating the code into the page is VERY easy.

In the header of the page add the following css includes.

<link rel="stylesheet" type="text/css" href="http://yui.yahooapis.com/combo?2.6.0/build/calendar/assets/skins/sam/calendar.css">

Today I’m going to start a three part tutorial in implementing a custom datagrid with prototype & scriptaculous. In part 1 we’ll explore the html & css underlying the widget. Parts 2 & 3 will look at interactivity and legacy browser support (IE 6).

Disclaimer: this project is designed to work on IE 7 and later. It will not render properly on IE 6. We will look into that more with part 3.

So it starts with a table. Tables are much maligned nowadays. The focus is on semantic markup and creative uses of <div> and <span>. In the energy behind css layouts over the past few years, the new markup elements available to the venerable table have been slightly overlooked. Sure the reign of table based layouts is over, but tables are now able to display data more semantically and style it more simply than ever before.

Here’s a traditional HTML table to start from.

<table>
<tr><td> Item Number</td><td>Description</td><td>Qty</td><td>Unit Price</td><td>Total Price</td></tr>
<tr><td>0023</td><td> Apples</td><td>3</td><td>.56</td><td>1.68</td></tr>
<tr><td>0057</td><td> Pears</td><td>13</td><td>.74</td><td>9.62</td></tr>
<tr><td>0137</td><td> Bananas</td><td>8</td><td>.31</td><td>2.48</td></tr>
<tr><td>0587</td><td> Kumquats</td><td>17</td><td>.26</td><td>4.42</td></tr>
<tr><td>0054</td><td> Oranges</td><td>3</td><td>.45</td><td>1.35</td></tr>
<tr><td></td><td>Total</td><td>44</td><td></td><td>19.55</td></tr>
</table>

It’s a decent start, but we can do better. First lets separate the body from the head with <thead> & <tbody> tags. We’ll also replace the header cells with <th> tags to denote their importance. We’re also going to add a set of row numbers. We’ll use <th> for these as well to signify that they aren’t really part of the data (note the empty <th/> we added to the header to make everything stay consistent).

<table>
<thead>
<tr><th /><th> Item Number</th><th>Description</th><th>Qty</th><th>Unit Price</th><th>Total Price</th></tr>
</thead><tbody>
<tr><th>1</th><td>0023</td><td> Apples</td><td>3</td><td>.56</td><td>1.68</td></tr>
<tr><th>2</th><td>0057</td><td> Pears</td><td>13</td><td>.74</td><td>9.62</td></tr>
<tr><th>3</th><td>0137</td><td> Bananas</td><td>8</td><td>.31</td><td>2.48</td></tr>
<tr><th>4</th><td>0587</td><td> Kumquats</td><td>17</td><td>.26</td><td>4.42</td></tr>
<tr><th>5</th><td>0054</td><td> Oranges</td><td>3</td><td>.45</td><td>1.35</td></tr>
<tr><td></td><td>Total</td><td>44</td><td></td><td>19.55</td></tr>
</tbody></table>

The <thead> specifies the header content. When printed, a browser should print it on every page the table spans. More importantly for us, it is a unique dom node we can grab for styling instructions. <tbody> works in a similar way, It allows us to break the internals of a table into a set of segments. This will come in handy later. <th> is a different beast entirely. I like to think of it as the ying to <td>’s yang. <th> & <td> are to <table> what <dt> & <dd> are to <dl>: a semantic way to denote name / value pairs.

Now that our table has a header and a body, It’s time to give it a footer. We’ll do this by using the <tfoot> tag.

At first glance, there is visually no difference between the 2nd and 3rd examples. Both of them look identical. The source, tells a different story. In the 3rd example, the footer row is actually ahead of the <tbody> in the source. This is the beauty of <tfoot> It lets us place the footer early in the table and cleanly separate it from the tbody that follows. It also guarantees that the <tfoot> appears last no matter what we append to the table via script.

All of this looks good, except it would be great if the columns were better styled.  The two columns with financial data especially should be aligned left to ensure that the decimal points align.  In a perfect world, we’d be able to do this with column groups, but that’s something for part 2.

I’m a javascript harlot and proud of it.  I espouse no allegiance to any particular framework, widget or philosophy and pride myself n my ability to select the best tools for the job based on a project’s unique constraints.  I find this puts me in a slightly unique position among developers.  I don’t carry the deep and intimate details of the framework in my brain, instead I prefer to maintain a much shallower depth of understanding.  I prefer road maps and traffic advisories to in depth aboriginal understanding.

This is why I was affected so severely by what seems to superficially be a minor inconvenience: the Scriptaculous wiki outage.  Scriptaculous has already lagged behind prototype in its depth of documentation.  This makes sense, after all, much of the heavy lifting and complex API’s are handled by prototype so an extensive documentation isn’t really necessary.  For most developers, a few well executed demo implementations of the key features are all we need to get the job done.  In fact, well executed demo implementations are especially critical for a framework like scriptaculous where many of the key features require complex implementation and are likely to be only used once or twice per project and not necessarily referenced day in and day out as the project comes together.

Last week, I was tasked to work on just such a feature.  We new the type ahead find was straightforward to implement given the Scriptaculous documentation.  We also knew that it was fundamentally gravy.  Sure, the feature was important to the end product and would mean much of the difference between user frustration and adoption, but It was also significantly less important than some other items like successfully storing to the database, authentication and form processing.  In short, we put it off to the end as I’m sure many developers would.

Unfortunately, the documentation was gone when we needed it.  The wiki outage had hosed the Scriptaculous hosted media wiki instance and the page we needed was simply missing from the new system.  During a several minute minor panic we tried the various internet archives and similar sites in a desperate attempt to find a new solution with negligible success.  Eventually we found the documentation we needed.  

To Scriptaculous’s credit it was in a surprisingly logical place and well done.  Turns out that scriptaculous has wonderful self documentation as part of the functional tests / unit tests suite.  These test files provided us with solid demonstrations of features we were looking to use for this project.

There’s no doubt in my mind that a software component’s single biggest asset is its documentation.    This is as much a feature as an ultra-fast query selector or smoothly transitioning widget.  Scriptaculous provides powerful documentation in a slightly unlikely place but doesn’t provide decent bread crumbs to its existence from the frameworks public site. Given the critical nature of such documentation, It would be nice if it integrated in to the public site or atleast minimally referenced as a resource.

I’m always looking for ways to improve my javascript development and after a few weeks of playing, Javascript MVC test looks like it might be one the best tools yet.

We all know the power of testing our code.  A proper suite of unit tests can be among a projects most valuable assets.  They can ensure against the regressions rampant in rapid application development cycles that may not have adequate opportunities for proper QA.  Most importantly, when coupled with continuous integration tools, a comprehensive test suite catches many bugs close to when they are written and when they are easiest to correct.

Historically, testing javascript hasn’t been the most useful or productive of tasks.  The type of data manipulation, object inheritance and communication most conducive to unit testing has been minimized in most javascript applications.  Instead, most javascript is highly event driven and is often loosely tied to any specific server side data model.  Test MVC stands to provide a powerful testing framework for just those tasks we normally use javascript for.

Key Features

• Cross browser¹ support for typical DOM events, like keypress, click, submit, blur, and focus
• Simulate writing text or dragging an element
• Easily simulate AJAX functionality with sample data in fixture files

Let’s face it, prototyping and mock-ups are a pain in the rear. I’m always looking for ways to streamline the early phases of the design process. Today I found one that is simply brilliant.

Meet GUIMags: Simple, whiteboard magnets of common UI components.

Now you can do mockups on the whiteboard with high fidelity symbols that photograph well. Instead of sketching out the entire design for each iteration, you can simply rearrange elements and erase / rewrite labels as you collaboratively work through a design. When you’re done. You can simply take a picture of the whiteboard and start coding your mockup.

You can find GuiMags here:

http://www.guimags.com/index.php

DOMAssitant 2.7 is a solid improvement to the DOMAssistant framework with a clear focus on CSS.

New functions:

• cssSelect
• AJAX
• setStyle
• setErrorHandling
• first

Other Improvements

• Dramatic Improvements to the CSS Selector performance: I personally consider CSS selectors the most important feature of a framework so the dramatic improvements really help sell me the benefits of the 2.7 release.
• Unicode Support.  This can be a really big one for a variety of reasons.  Personally, I think it should be built into all frameworks from day one (It is built into javascript after all).

You can find out more about the new release here:

http://www.robertnyman.com/2008/04/09/domassistant-27-released-better-faster-slimmer-new-features/