Dojo Toolkit中的define参数

Question

I am new to dojo. I have defined a widget and if looks like this:

define(["dojo/_base/declare", "dijit/_Widget", "dijit/_TemplatedMixin", "dojo/text!Widgets/Templates/Screen.html", "./Node", "dojo/_base/array", "dojo/dom-geometry", "dojo/dom-style"],
    function (declare, widget, templated, template, node, array, domGeometry, domStyle) { 
...

I don't know if this is how it should be. Is it ok that I have so long list of requirements or do I need to require them inside the callback.

Answer 1

That's not a particularly long list of modules. Dojo breaks its functionality down into quite small modules, so it's pretty usual to be fetching quite a few of them.

You definitely don't want to be requiring them in the callback. define is basically the same as require , but used at the top of a module for declaring the result of an asynchronous module with dependencies.

One thing worth noting is that it's probably worth injecting class dependencies to parameters with the same, or similar names: it makes the resultant declare call simpler, eg

define(["dojo/_base/declare", "dijit/_WidgetBase", "dijit/_TemplatedMixin", "dojo/text!mytemplate.html"], function(declare, _WidgetBase, _TemplatedMixin, template) {

    return declare("my.Widget", [_WidgetBase, _TemplatedMixin], {
        templateString: template
    };
});

You may also wish to group your dependencies together into logical groups, eg put your base classes together, helper modules together. You'll also be wanting to declare any other modules mentioned in your template, at the end of the module list, and you don't necessarily need to declare those as callback parameters if you're not using them in your code, eg used/by/template1 and used/by/template2 here:

define(["dojo/_base/declare", "dijit/_WidgetBase", "dijit/_TemplatedMixin", "dojo/text!mytemplate.html", "used/by/template1", "used/by/template2"], function(declare, _WidgetBase, _TemplatedMixin, template) {

    return declare("my.Widget", [_WidgetBase, _TemplatedMixin], {
        templateString: template
    };
});