Quick Validating JavaScript Function Before Call

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There are many instances where we have to execute a function where we have no idea whether it actually exists or not. Let’s say for example, a function expects another function passed to it as parameter, which would later be executed as callback. A very common usage would be the callback function sent to AJAX requests.

Generally, we would code it with an if-block and check whether the variable (say, callback) is a function or not. If it is, we execute it when we have the work completed (say marked by a variable called workIsDone.)

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Setting Default Variable Value in JavaScript

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Often, there are conditions where we need to provide a default value of a variable if it is undefined. As a case study, we will take up the situation, where we are passing a Boolean value to function and if the input is true, some action has to be taken. In case someone does not pass any value, the input is assumed to be true.

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Infinite Ways to Detect Array in JavaScript

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JavaScript (ECMA script in general) is a miraculous language. It allows us to prove that coding is creativity. One reason for that is the numerous ways a single objective can be coded. For instance, checking whether a variable is an Array, can be done in four different ways. And probably more!

Some months back I had come across this Quora article: What's the best way to tell the different between an Array and other kinds of objects in JavaScript? There were already five different methods available there from Tom, John, Rick, Ken and Eric. And even I was surprised that I could add one more! I would take some time and explain all the methods with its pros and cons and finally we can conclude upon the best method.

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Minor Bug Fix to jQuery Touch Drag Plugin

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On 21st of June, the jQuery drag event plugin with iPhone (iOS) touch support was released. It has helped to add touch-based drag functionality to many existing web applications using the jQuery drag plugin. A minor update is released for this plugin that fixes the possibility of lack of touch-drag functionality on certain touch devices.

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JavaScript Drag Events on iPhone and Other Touch Based Devices

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For quite a while this week, we were trying to work on dragging JavaScript elements on iPad and other devices with touch input. For our case, we already had jQuery included in our codes, hence we were tempted to use the touchmove event and depend on native jQuery to do the rest.

Things turned out to be a bit trickier. After implementation, it struck us that with jQuery bound events, event.pageX and other related mouse coordinate attributes would not work. Add to that, we were using the jQuery.event.drag plugin by ThreeDubsmedia to seal of the dirty job of drag-related coding.

Armed with the above two problems, we started to do what we thought would be the fastest solution – modify the jQuery.event.drag plugin for a graceful upscale!

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