dojo.provide("dojo.AdapterRegistry");
dojo.require("dojo.lang.func");
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.
this.pairs = [];
this.returnWrappers = returnWrappers || false;
}
dojo.lang.extend(dojo.AdapterRegistry, {
register: function(name, check, /*Function*/ wrap, directReturn, override){
// summary:
// register a check function to determine if the wrap function or
// object gets selected
// name: String
// a way to identify this matcher.
// check: Function
// 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: Boolean?
// 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: Boolean?
// If override is given and true, the check function will be given
// highest priority. Otherwise, it will be the lowest priority
// adapter.
var type = (override) ? "unshift" : "push";
this.pairs[type]([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");
// dojo.raise("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;
}
});