ttrss/lib/dojo/AdapterRegistry.js

108 lines
3.6 KiB
JavaScript

/*
Copyright (c) 2004-2011, The Dojo Foundation All Rights Reserved.
Available via Academic Free License >= 2.1 OR the modified BSD license.
see: http://dojotoolkit.org/license for details
*/
if(!dojo._hasResource["dojo.AdapterRegistry"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojo.AdapterRegistry"] = true;
dojo.provide("dojo.AdapterRegistry");
dojo.AdapterRegistry = function(/*Boolean?*/ returnWrappers){
// summary:
// A registry to make contextual calling/searching easier.
// description:
// Objects of this class keep list of arrays in the form [name, check,
// wrap, directReturn] that are used to determine what the contextual
// result of a set of checked arguments is. All check/wrap functions
// in this registry should be of the same arity.
// example:
// | // create a new registry
// | var reg = new dojo.AdapterRegistry();
// | reg.register("handleString",
// | dojo.isString,
// | function(str){
// | // do something with the string here
// | }
// | );
// | reg.register("handleArr",
// | dojo.isArray,
// | function(arr){
// | // do something with the array here
// | }
// | );
// |
// | // now we can pass reg.match() *either* an array or a string and
// | // the value we pass will get handled by the right function
// | reg.match("someValue"); // will call the first function
// | reg.match(["someValue"]); // will call the second
this.pairs = [];
this.returnWrappers = returnWrappers || false; // Boolean
};
dojo.extend(dojo.AdapterRegistry, {
register: function(/*String*/ name, /*Function*/ check, /*Function*/ wrap, /*Boolean?*/ directReturn, /*Boolean?*/ override){
// summary:
// register a check function to determine if the wrap function or
// object gets selected
// name:
// a way to identify this matcher.
// check:
// a function that arguments are passed to from the adapter's
// match() function. The check function should return true if the
// given arguments are appropriate for the wrap function.
// directReturn:
// If directReturn is true, the value passed in for wrap will be
// returned instead of being called. Alternately, the
// AdapterRegistry can be set globally to "return not call" using
// the returnWrappers property. Either way, this behavior allows
// the registry to act as a "search" function instead of a
// function interception library.
// override:
// If override is given and true, the check function will be given
// highest priority. Otherwise, it will be the lowest priority
// adapter.
this.pairs[((override) ? "unshift" : "push")]([name, check, wrap, directReturn]);
},
match: function(/* ... */){
// summary:
// Find an adapter for the given arguments. If no suitable adapter
// is found, throws an exception. match() accepts any number of
// arguments, all of which are passed to all matching functions
// from the registered pairs.
for(var i = 0; i < this.pairs.length; i++){
var pair = this.pairs[i];
if(pair[1].apply(this, arguments)){
if((pair[3])||(this.returnWrappers)){
return pair[2];
}else{
return pair[2].apply(this, arguments);
}
}
}
throw new Error("No match found");
},
unregister: function(name){
// summary: Remove a named adapter from the registry
// FIXME: this is kind of a dumb way to handle this. On a large
// registry this will be slow-ish and we can use the name as a lookup
// should we choose to trade memory for speed.
for(var i = 0; i < this.pairs.length; i++){
var pair = this.pairs[i];
if(pair[0] == name){
this.pairs.splice(i, 1);
return true;
}
}
return false;
}
});
}