The function we pass to dojo. Handily, Dojo has a version property that's useful for demos like this. As we get further into learning Dojo, the alert is going to get increasingly annoying, and we'll want to learn about logging to a browser console. But for now, we'll stay focused, and move on. Loading Dojo is great, however it's more likely that you want to manipulate the page you just loaded Dojo into. We'll be digging into this in much more detail in other tutorials.
This time, in our ready function, we use dojo. Note that you can have as many calls to dojo. In practice, if you have more than a few lines of code, it's common to define a named non-anonymous function and pass that to dojo.
If you came here for Dojo's Hello World, then we are long done. A custom build, however, allows you to create layers bundles of classes , also speeding up loading. You can use it either by direct loading:. Note that if you use the Google API, google. See the code example below. AOL also hosts a cross-domain Dojo distribution.
To use it, include the following script tag in your page:. As it turns out, this top-level directory also designates a namespace for the code it contains.
In a logical sense, modules in Dojo are similar to the concept of packages in other programming languages in that they are used to compartmentalize related software components. When it becomes necessary to split a Dojo module into multiple files, or when a module consists of only a single JavaScript file, each JavaScript file is referred to a resource.
Although a resource could strictly be used to logically organize the various abstractions that are associated with a module, there is also the consideration of minimizing the size of a JavaScript file. Physically, Dojo namespaces map to the same filesystem hierarchy that specifies modules and resources; logically, the concept of a namespace prevents identically named modules and resources from clashing.
Note that while namespaces themselves are neither modules nor resources, the semantic idea behind what they represent does directly map to modules and resources.
It is also worthwhile to note that Dojo preserves the global namespace of a page, and any modules you create with Dojo do not pollute the global namespace if implemented properly. Recall that everything in Base fits into the top-level dojo namespace. In computer programming, something is first-class when it can be passed around without restrictions compared to other entities in the same language.
For example, in many programming languages, you cannot pass around functions in the same way that you can pass around other data types such as number or string values. In this particular context, functions would not be considered first-class objects.
In our discussions, the most common way this term will be used is to highlight the fact that functions are first-class objects in JavaScript. A function is a code snippet that is defined once, but can be executed multiple times.
In JavaScript, functions are first-class objects that can be passed around just like any other variable. A constructor function is a function that is used specially via the new operator, which creates a new JavaScript Function object and performs initialization on it.
In Dojo parlance, the term constructor may also refer to the anonymous function that maps to the constructor key in dojo. The most generic concept of an object in JavaScript refers to a compound data type that can contain any number of named properties. Technically speaking, JavaScript only has objects and no classes—even though Dojo simulates the notion of a class via the dojo.
In OOP, any piece of data stored in a class is commonly called a property. In our Dojo-specific discussions, this term may refer to data contained in Function objects or to data contained in Dojo classes that are defined by dojo. A function that is a member of a class is commonly referred to as a method in broad OOP contexts, JavaScript, and Dojo. Furthermore, in Dojo parlance, the anonymous functions that appear in the dojo. In general, you might just do well to think of a method as a function defined on a class that is subsequently used through an object context.
In Dojo, a declaration that represents a logical entity as defined via the dojo. A Dojo widget is a Function object that is created via a dojo. Usually, a widget has a visible appearance on the screen and logically bundles HTML, CSS, JavaScript, and static resources into a unified entity that can easily be manipulated, maintained, and ported around just like a file.
This section discusses some material that you may want to initially skim over and come back to review once you feel well acquainted with Dojo. Before you can use Dojo at all, you have to somehow get it into the page. Well, not quite. Save yourself some typing by copying it into a template that you can reuse. Anonymous functions and some of the reasons they are important were briefly discussed in the Preface.
Two new constructs in the previous listing include the dojo. One incredibly important aspect of dojo. That distinction is especially important as it relates to dojo. Because dojo. Then, when you try to reference a module requested via dojo. The technical term for the situation in which the outcome is undefined because of unpredictable timing constraints that compete with one another is called a race condition.
For the reasons just mentioned, using dojo. A common mistake is not using dojo. More specifics on djConfig are coming up later in this chapter. Determines Dojo should be cross-domain loaded or loaded locally. XDomain loading details happen transparently so long as an Internet connection is available and the inclusion of the XDomain loader was configured at build time.
By default, configuring for XDomain loading produces a dojo. Based on the environment specified for the particular build of Dojo usually the browser but it could also be another option such as Rhino or a mobile device , sets up any environment-specific features. Workarounds for browser incompatibilities such as normalizing DOM events, standardizing a map of key codes, and extra measures to minimize and prevent memory leaks are also handled.
Establishes the dojo namespace so that all of the utility provided by the toolkit does not clobber any existing symbols in the page. Loads the dojo namespace with the various functions and symbols that constitute Base. Although less frequently used than dojo. Upcoming sections introduce djConfig , a configuration switch that you can place in the SCRIPT tag that bootstraps the toolkit or define anytime before Dojo bootstraps to customize where it looks for resources, whether debugging tools should be wired in, and so on.
Some of the commentary may introduce constructs that have not yet been introduced. For now, just skim over those and come back to them whenever the occasion calls for it. Used to facilitate injecting Dojo into a page after it has already been loaded. Useful for hacking on a page or developing widgets that are necessarily lazy-loaded, i. Technically, this parameter allows you to redefine the root level path of the toolkit for a local or an XDomain load, usually for the purpose of resolving dependencies such as custom modules.
In practice, however, it is almost exclusively used to resolve local modules when bootstrapping over XDomain. In the case of a String value, appends the value provided to requests for modules so that previous version of the page that is cached locally will be overridden.
Typically, this value will be a random string of characters that you generate yourself or a unique identifier for your application version that would prevent nasty bugs from surfacing that may be caused by older versions of modules.
During the development cycle, you might provide a Date value such as new Date. Usually provides more specific debugging information at the cost of performance. You might specify this value to better track down the line number where an error occurred if you are told that an error originated in a build file like bootstrap.
Used to provide the location for a special file that is used in combination with dojo. Gecko-based browsers like Firefox may optionally use the DOMContentLoaded event as the trigger to signal that the page has loaded because of a technical nuance related to synchronous XHR request involving a document greater than bytes [ a ].
Active Oldest Votes. Improve this answer. Tim Fountain Tim Fountain That is the heart of my problem; The occurrence of 'dojo. As you say it is suggestive of a ZF bug, but I wanted other better informed minds than mine sanity check the issue in case I was victim of my own lack of knowledge. Or more clean, use the helper method: setCdnDojoPath to set the correct path and name Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown.
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