Pull to Refresh

Pull to refresh is a common design pattern amongst major mobile apps. Facebook, twitter, gmail, etc all use a “pull to refresh” technique. In my previous post on the new Quick Return design pattern, I discussed a way to implement this in a desktop environment. Now, I present to you, how to implement the “Pull to Refresh” design pattern on the desktop:

Demo

Usage:

Simply download the JS source or copy/paste the JS source below and include it in your markup.

A global, called Refreshable, becomes available once the script is included. To use, you can call its initialize(), which takes in 2 options as an object{}:

  1. refreshAction
  2. refreshContainer

refreshAction must be a function. It is the action you want to bind to the refresh event triggered on the refreshContainer.

refreshContainer needs to be addressed by an ID. The script, at this time, doesn’t support an array of elements.

So, in the source below you’ll see where I initialized it saying:

Refreshable.initialize({
refreshAction: function() {
$.getJSON("http://date.jsontest.com/", function(data) {
$("#container p").html("Today is " + data.date + " and it is " + data.time);
});
},
refreshContainer: "#container"
});

I’m passing in a function that goes and fetches the current date and time from a provider, then updates the container w/ this information.

HTML:

<div id="container" class="container">
<p>Pull my bottom</p>
</div>

CSS:

.container { 
width: 350px;
height: 350px;
padding: 5px;
margin: 5px;
background: #ccc;
position: relative;
border-bottom-right-radius: 10px;
}

JS:

var Refreshable = (function () {
var refreshAction;
var refreshContainer;
var $refreshContainer;
var refreshContainerHeight;
var refreshElString;
var $refreshEl;
var offset;
var offsetDiff; startHover = function (evt) {
$(this).css("background-color", "rgba(0,0,0,0.5)");
}
stopHover = function (evt) {
$(this).css("background-color", "transparent");
}
allowResize = function (evt) {
evt.preventDefault();
$refreshContainer.addClass("resizable");
offset = evt.pageY;
}
stopResize = function (evt) {
$refreshContainer.removeClass("resizable");
$refreshContainer.animate({
height: refreshContainerHeight
});
offset = 0;
}
resize = function (evt) {
if ($refreshContainer.hasClass("resizable")) {
offsetDiff = evt.pageY - offset;
if (offsetDiff > 0) {
$refreshContainer.innerHeight(refreshContainerHeight + offsetDiff);
}
if (offsetDiff > refreshContainerHeight * 0.25) {
$refreshContainer.trigger("refresh");
}
}
}
var refreshIt = function () {
stopResize();
refreshAction();
} return {
initialize: function (options) {
refreshAction = options.refreshAction;
refreshContainer = options.refreshContainer;
$refreshContainer = $(options.refreshContainer);
refreshContainerHeight = $(refreshContainer).innerHeight();
refreshElString = '<div class="refreshEl" style="position:absolute; width: 100%; height: 45px; bottom: 0; left: 0; cursor: s-resize; outline: 50px transparent solid; z-index: 999999; border-bottom-right-radius: 10px;"></div>';
$refreshContainer.append(refreshElString);
$refreshEl = $refreshContainer.children(".refreshEl").first();

this.eventRegister();
return this;
}, eventRegister: function () {
$refreshContainer.on("refresh", refreshIt);
$refreshEl.on("mousedown", allowResize)
.on("mouseup", stopResize)
.on("mousemove", resize)
.on("mouseleave", stopHover)
.on("mouseover", startHover); }
}; })();
//Code you saw before Refreshable.initialize({
refreshAction: function() {
$.getJSON("http://date.jsontest.com/", function(data) {
$("#container p").html("Today is " + data.date + " and it is " + data.time);
});
},
refreshContainer: "#container"
});

I wanted to keep the CSS down to a minimum for portability. The CSS included is simply for the container to serve as a demo, it doesn’t have to be followed strictly.

The only requirement of the CSS is that it needs to be positioned relatively. Otherwise, the refresh element appended to the bottom will not seat inside the container.

That’s all I have for now. As with my other posts, I’ll be making edits to make the code better, more extendable, etc.

Thanks for reading.

 

Actually Vertically-Aligned CSS (no javascript necessary, horizontally aligned bonus!)

.vertical-align-container { height: 100%; position: absolute; top: 0; right: 0; bottom: 0; left: 0; text-align: center; }
.vertical-align-container::after { content: ''; display: inline-block; height: 100%; margin-right: -0.25em; vertical-align: middle; }
.vertical-align-container > .vertical-align-content { display: inline-block; vertical-align: middle; }

That’s it. That’s the magic secret.

For those of you that just want to c/p to see it for yourselves:
<html>
<head>
<style>
.vertical-align-container { height: 100%; position: absolute; top: 0; right: 0; bottom: 0; left: 0; text-align: center; }
.vertical-align-container::after { content: ''; display: inline-block; height: 100%; margin-right: -0.25em; vertical-align: middle; }
.vertical-align-container > .vertical-align-content { display: inline-block; vertical-align: middle; }
</style>
</head>
<body>
<div class="vertical-align-container">
<div class="vertical-align-content">
Here is something vertically aligned
</div>
</div>
</body>
</html>

I hope you find this helpful. If you do –

Follow me on twitter @william_beard

Sanitize Backbone.js Models to prevent XSS

This isn’t groundbreaking code, but you may find it useful to know how to take a step to prevent XSS attacks when implementing Backbone MV*. Some JavaScript frameworks automatically escape or sanitize the values being passed to the model. Backbone does not. However, the library it’s built on (Underscore.js) does provide an easy way to escape values.

First, in your Model, create your initialize() method, and in it, use the _.each method to iterate over the attributes object, passing the value to a method belonging to the Model named “sanitize”.

var CartItem = Backbone.Model.extend({
  initialize: function() {
    _.each(this.attributes, function (val, key)
      this.set(key, this.sanitize(val));
    }, this);
  }
});

Let’s add our sanitize() method. In this method, simply take in the string as a parameter, and return the escaped version of it, using Underscore’s _.escape method.

var CartItem = Backbone.Model.extend({
  initialize: function() {
    _.each(this.attributes, function (val, key) {
      this.set(key, this.sanitize(val));
    }, this);
  },
  sanitize: function (str) { 
    return _.escape(str) 
  } 

});

I recommend sanitizing in your model’s initializer so that you ensure it’s properly scrubbed before calling Model.save() and sending nasty XSS or SQL injection to your server. Also, sanitize anywhere you update the model or allow edits to the model.

I hope you found this post useful. If you have anything to add or find any problems, let me know.

formValidator.js – Simple jQuery form validation plugin

Made my first jQuery plugin for validating forms on the front-end, before submit. It has some options as well to make it more flexible for your needs.

To use the plugin, please download the source from my github repo: https://github.com/wbeard/formvalidator

I plan on adding more to it. Here are some things to cover:

To Use:

import jQuery 1.72 js file

import validate.js file

link validate.css file

attach to desired form (e.g. $(“selector”).formValidator();

can take options such as background & color for customization (e.g. $(“selector”).formValidator({ “background”: “red”, “color”: “white” });

when you define a dom element add the appropriate classes for validation to happen on change or keyup, whichever is defined in the plugin

Classes:

required – defines required input

numeric – requires numeric input

phone – masks text with (###) ###-####

date – masks text with date mm/20yy

card – accepts only 3,4,5, or 6 as valid first character and determines appropriate max length of cvv input box and itself

email – simple regex expression being checked against

Options:

background – Sring value. Background of tooltip, default is transparent

color – String value. Font color of tooltip, default is red

orientation – String value.  Position of tooltip. Valid options are right, top, left, or bottom. Default is right.

disableSubmit – Boolean. Determines whether submit button associated with selected form should be disabled until all fields are valid. Default is true.

excludedList – If there are other buttons being selected and you would like to explicitly not select them, pass them in an array,  with a jQuery selector, e.g. $(“.selector”)

Feel free to check out the source or fork at https://github.com/wbeard/formvalidator/

I’ll be making this more scalable and easy to use. Its been made more specifically for an .aspx page for collecting payments, so some of its quirks were caused by the quirks of creating jQuery for aspx & .net. I’ll be making a more generic approach and will update accordingly.

Thanks!

Finding Motivation

The ThinkerIs it bad to be motivated by jealousy? Or the want to rub your success in somebody else’s face? To get the satisfaction of telling them, “I told you so”?

It’s hard to find motivation in this world. There are so many cliche reasons out there to strive to be the best, perhaps it’s healthy to have motivation, no matter the means.

This sort of internal conflict reminds me of the dogma of Jedi vs. dogma of the Dark Side. One is more powerful than the other, they are both driven by 2 completely different emotional forces. But, one is more sustainable than another. Who then, is right?

It’s hard to say.

In time

Love: We fall in it and out of it as if it were a net. We make it as if it were an object. We have it for others from family, to friends, to significant others. Yet, none of us can agree on what it is, or how to define it.

Life: It is nothing but a soil through which we extend our roots. Experiences are the minerals which enrich us and spread our roots through life. Once in a while, our roots cross and grow through the roots of others. The more experiences you physically share with others, the longer your connection through life lasts. The less you experience with others, the more in solitude you grow.

Finite

Photo by Jordan Douglas

A calm, glistening sheen of blue,
Reflects a life so unfamiliar to millions.
And conceals an entire truth,
Held by a life which stands with resilience.

It’s exposed the life of one
Who stands tall but alone.
Outgrown by its will to the sun,
The ground has decayed and its roots are shown.

The persistent nature of nature itself,
In where a cycle destroys a life,
Seems to make room on a shelf,
And pounds like a drum to give a rhythm to strife.

Though, what makes this exception so uncanny
Is not found in its persistency,
But rather, in its foundation
And overexposed consistency.

So, how can one who shows his cards,
Win with a hand of such low probability?
Perhaps it’s the faith in what he possesses,
Knowing nature could not replace such rarity.

Photo by Jordan Douglas