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174 lines
6.5 KiB
JavaScript
174 lines
6.5 KiB
JavaScript
![]()
12 years ago
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define("dojo/has", ["require", "module"], function(require, module){
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// module:
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// dojo/has
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// summary:
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// Defines the has.js API and several feature tests used by dojo.
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// description:
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// This module defines the has API as described by the project has.js with the following additional features:
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//
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// - the has test cache is exposed at has.cache.
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// - the method has.add includes a forth parameter that controls whether or not existing tests are replaced
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// - the loader's has cache may be optionally copied into this module's has cahce.
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//
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// This module adopted from https://github.com/phiggins42/has.js; thanks has.js team!
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// try to pull the has implementation from the loader; both the dojo loader and bdLoad provide one
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// if using a foreign loader, then the has cache may be initialized via the config object for this module
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// WARNING: if a foreign loader defines require.has to be something other than the has.js API, then this implementation fail
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var has = require.has || function(){};
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if(! 1 ){
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var
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isBrowser =
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// the most fundamental decision: are we in the browser?
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typeof window != "undefined" &&
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typeof location != "undefined" &&
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typeof document != "undefined" &&
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window.location == location && window.document == document,
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// has API variables
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global = this,
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doc = isBrowser && document,
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element = doc && doc.createElement("DiV"),
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cache = (module.config && module.config()) || {};
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has = function(name){
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// summary:
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// Return the current value of the named feature.
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//
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// name: String|Integer
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// The name (if a string) or identifier (if an integer) of the feature to test.
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//
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// description:
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// Returns the value of the feature named by name. The feature must have been
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// previously added to the cache by has.add.
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return typeof cache[name] == "function" ? (cache[name] = cache[name](global, doc, element)) : cache[name]; // Boolean
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};
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has.cache = cache;
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has.add = function(name, test, now, force){
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// summary:
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// Register a new feature test for some named feature.
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// name: String|Integer
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// The name (if a string) or identifier (if an integer) of the feature to test.
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// test: Function
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// A test function to register. If a function, queued for testing until actually
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// needed. The test function should return a boolean indicating
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// the presence of a feature or bug.
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// now: Boolean?
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// Optional. Omit if `test` is not a function. Provides a way to immediately
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// run the test and cache the result.
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// force: Boolean?
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// Optional. If the test already exists and force is truthy, then the existing
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// test will be replaced; otherwise, add does not replace an existing test (that
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// is, by default, the first test advice wins).
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// example:
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// A redundant test, testFn with immediate execution:
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// | has.add("javascript", function(){ return true; }, true);
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//
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// example:
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// Again with the redundantness. You can do this in your tests, but we should
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// not be doing this in any internal has.js tests
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// | has.add("javascript", true);
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//
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// example:
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// Three things are passed to the testFunction. `global`, `document`, and a generic element
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// from which to work your test should the need arise.
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// | has.add("bug-byid", function(g, d, el){
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// | // g == global, typically window, yadda yadda
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// | // d == document object
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// | // el == the generic element. a `has` element.
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// | return false; // fake test, byid-when-form-has-name-matching-an-id is slightly longer
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// | });
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(typeof cache[name]=="undefined" || force) && (cache[name]= test);
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return now && has(name);
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};
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// since we're operating under a loader that doesn't provide a has API, we must explicitly initialize
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// has as it would have otherwise been initialized by the dojo loader; use has.add to the builder
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// can optimize these away iff desired
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1 || has.add("host-browser", isBrowser);
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1 || has.add("dom", isBrowser);
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1 || has.add("dojo-dom-ready-api", 1);
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1 || has.add("dojo-sniff", 1);
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}
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if( 1 ){
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// Common application level tests
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has.add("dom-addeventlistener", !!document.addEventListener);
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has.add("touch", "ontouchstart" in document);
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// I don't know if any of these tests are really correct, just a rough guess
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has.add("device-width", screen.availWidth || innerWidth);
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// Tests for DOMNode.attributes[] behavior:
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// - dom-attributes-explicit - attributes[] only lists explicitly user specified attributes
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// - dom-attributes-specified-flag (IE8) - need to check attr.specified flag to skip attributes user didn't specify
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// - Otherwise, in IE6-7. attributes[] will list hundreds of values, so need to do outerHTML to get attrs instead.
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var form = document.createElement("form");
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has.add("dom-attributes-explicit", form.attributes.length == 0); // W3C
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has.add("dom-attributes-specified-flag", form.attributes.length > 0 && form.attributes.length < 40); // IE8
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}
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has.clearElement = function(element){
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// summary:
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// Deletes the contents of the element passed to test functions.
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element.innerHTML= "";
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return element;
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};
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has.normalize = function(id, toAbsMid){
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// summary:
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// Resolves id into a module id based on possibly-nested tenary expression that branches on has feature test value(s).
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//
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// toAbsMid: Function
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// Resolves a relative module id into an absolute module id
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var
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tokens = id.match(/[\?:]|[^:\?]*/g), i = 0,
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get = function(skip){
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var term = tokens[i++];
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if(term == ":"){
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// empty string module name, resolves to 0
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return 0;
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}else{
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// postfixed with a ? means it is a feature to branch on, the term is the name of the feature
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if(tokens[i++] == "?"){
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if(!skip && has(term)){
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// matched the feature, get the first value from the options
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return get();
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}else{
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// did not match, get the second value, passing over the first
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get(true);
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return get(skip);
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}
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}
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// a module
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return term || 0;
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}
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};
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id = get();
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return id && toAbsMid(id);
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};
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has.load = function(id, parentRequire, loaded){
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// summary:
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// Conditional loading of AMD modules based on a has feature test value.
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// id: String
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// Gives the resolved module id to load.
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// parentRequire: Function
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// The loader require function with respect to the module that contained the plugin resource in it's
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// dependency list.
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// loaded: Function
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// Callback to loader that consumes result of plugin demand.
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if(id){
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parentRequire([id], loaded);
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}else{
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loaded();
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}
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};
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return has;
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});
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