Posts Categorized: Dojo Love

Storehouse – Client Side Object Storage for the Dojo Store API

It’s been some time since dojox/storage, and a lot of things changed since then. Most notably: Browsers now have IndexedDB, and Dojo now has the dojo/store API that widgets can directly work with.

The dojo/store API was built with IndexedDB and offline in mind, has a nice API and allows asynchronism, meaning that it can return Promises instead of values. The only thing missing was a persistence layer that would take data via that API and store it in the user’s browser, e.g. for offline availability.

And that’s what Storehouse is: A persistent object store implementing the dojo/store API.

read more »

Creating a persistent Dojo Object Store

[Note: This is a cross-post. I also published this on the uxebu blog.]

As of version 1.6, dojo comes with the new Dojo Object Store API. This is an awesome thing, as it greatly simplifies the work with data stores in Dojo. Everybody who had to do with the traditional dojo.data API felt it was overly complex and hard to use – this has finally changed now. There are also wrappers from and to the old and new APIs, so that you can do stuff like using your traditional data-aware widgets with a new Object Store. And the goodness doesn’t end here; but more on this later. If you haven’t done so yet, you might want to read the excellent post on the new Dojo Object Stores by Kris Zyp where he explains all the awesomeness he created.

read more »

Encrypted client-side storage with dojo

A couple of days ago, Nicholas Zakas wrote an article about secure client side storage. I think the scenario he mentioned (working from a cyber cafe) is not unsafe by nature, and could be well handled by an application. Nonetheless, client side storage such as localStorage still is subject to DNS spoofing attacks (which is the main security issue, I think). To handle this, one needs to encrypt the keys and values in the store.

So here you go: dojox.storage.encrypted, a Blowfish encrypted storage. It sits on top of dojox.storage, and you get all the dojo storage manager goodness, mainly the automatic selection of the best storage provider available. It exposes the complete API that dojox.storage does. If an attacker gains access to the storage area, he can still nuke the storage, but the data found within will be useless.
read more »

Promises with dojo – a lightweight alternative to dojo.Deferred

Update: Micheil Smith had a cool idea to improve this and posted it in the comments. I have updated the test page and the code examples to reflect his idea. Thanks Micheil!

Update II: Ben Hockey proposed to do the whole thing without using the pub/sub system. I for one think its a good idea, but in case you want the topic version, I’ll leave the test page and add another one with the topic-less version. Thanks Ben!

Update III: Dojo 1.5 introduces robust Promises with dojo.deferred as Krys Zyp explains in this SitePen post.

One of the things/ideas/concepts that I really like about CommonJS is Promises.

Promises? A brief explanation from the CommonJS API:

Promises provide a well-defined interface for interacting with an object that represents the result of an action that is performed asynchronously, and may or may not be finished at any given point in time.

To hear more about Promises, I highly recommend these two posts.
read more »

Working with the Curve – Advanced Animation with Dojo

If you use animations, you probably use them to animate CSS properties. But this post is about some real bareknuckle animation – using the dojo toolkit. We’ll have a look into dojo.Animation and talk about the curve, the line, easing and rate, and we’ll check out (the somehow undocumented) dojox.fx._core – and see how to work with multidimensional lines.

read more »

persistent local storage with dojo

Update: The providers attached to this post are part of dojox.storage now – no need to download them, just get a copy of dojo, and everything is there.

Update II: dojox.storage won’t make it into dojo 2.0 and is not compatible with the new dojo/store API. For future-safe persistent client-side storage, see Storehouse – Client Side Object Storage for the Dojo Store API


Last year, Brian Leroux‘s Lawnchair caught my interest – it is an easy and fast way to access local persistant local storage.

Uh, persistant local storage?

Ahm, yeah, in case you don’t know, that means a client-side storage, be it in a browser, or in an Air app. It’s not very popular, but that concept has been around for a long time. So why local? There are two major reasons for it: First, we need this for apps and tools that work offline – and apps and tools that work online but need an offline backup and sync later. Kris Zyp wrote a post about the JsonRestStore and OfflineRest back in 2008, he goes a little into detail there. Secondly, we need it for apps and tools that rely on persistence for other reasons, no matter if online or offline – like it happended to me. When I ran into Lawnchair, I had the idea to build a tool that was monitoring CSS selector usage on websites and apps (you know how you sometimes lose control about CSS selectors in webapps…). To achieve this, I needed to store data locally, and persistent.
read more »

More fun with strings: dojo.string.contains()

In the series “convenience wrappers for small tasks that increase code readability”, today contains() is starring. Having a contains() method could also serve another purpose: to maybe prevent people from using match() to find out if a string contains a given substring (what is still proposed in some JS tutorials out there…). So, I want the contains() method to also have a switch to work case-insensitive.

Besides indexOf(), there are some other ways to achieve this, so – let’s have a competition and find out who’s the fastest!
read more »

Keyboard accessibility for dojox.layout.FloatingPane

Well, I don’t really see a use for FloatingPane, except as a windowing system for projects like LucidDesktop, but I got the impression that many people just love the FloatingPane. However, it caught my attention these days.

One of its major drawbacks – and the one that keeps it pretty far from becoming a joyful member of the dijit namespace – is the lack of keyboard accessibility. It has plenty of other issues and could use some refactoring, but this one is outstanding. Hm, adding keyboard access shouldn’t be too hard I thought and went for it…
read more »

dojo.string.beginsWith()

Most cases where you find String.substr() in the wild are to check if a given string begins with a certain other string. Be it checking for a prefix or sorting out zipcodes that begin with certain numbers. And because code readability is a good thing (really, it is important), it would be nice to have a String.beginsWith() method. Or, because of dojo love, a dojo.string.beginsWith() method.

Consider the following code:

var nearbyZipcodes = dojo.filter(givenZipcodes,function(zipcode){
    return dojo.string.beginsWith(zipcode,'12');
});

read more »

A collapsible fieldset as dojo widget

Though many people would disagree, I for one like to use fieldsets to structure complex forms. Even better do I like fieldsets that are collapsible.

As there is no such fieldset with dojo, I decided to write my own widget. While doing so, I learnt an interesting lesson…

First, I wrote it pretty simple, inheriting the widget from dijit._Widget and dijit._Templated. It had a toggle button next to its legend, which could be clicked. The toggle was a simple display none/block change.
read more »