spacedeck-open/public/javascripts/route-recognizer.js
2017-04-07 01:29:05 +02:00

628 lines
17 KiB
JavaScript

(function(__exports__) {
"use strict";
var specials = [
'/', '.', '*', '+', '?', '|',
'(', ')', '[', ']', '{', '}', '\\'
];
var escapeRegex = new RegExp('(\\' + specials.join('|\\') + ')', 'g');
function isArray(test) {
return Object.prototype.toString.call(test) === "[object Array]";
}
// A Segment represents a segment in the original route description.
// Each Segment type provides an `eachChar` and `regex` method.
//
// The `eachChar` method invokes the callback with one or more character
// specifications. A character specification consumes one or more input
// characters.
//
// The `regex` method returns a regex fragment for the segment. If the
// segment is a dynamic of star segment, the regex fragment also includes
// a capture.
//
// A character specification contains:
//
// * `validChars`: a String with a list of all valid characters, or
// * `invalidChars`: a String with a list of all invalid characters
// * `repeat`: true if the character specification can repeat
function StaticSegment(string) { this.string = string; }
StaticSegment.prototype = {
eachChar: function(callback) {
var string = this.string, ch;
for (var i=0, l=string.length; i<l; i++) {
ch = string.charAt(i);
callback({ validChars: ch });
}
},
regex: function() {
return this.string.replace(escapeRegex, '\\$1');
},
generate: function() {
return this.string;
}
};
function DynamicSegment(name) { this.name = name; }
DynamicSegment.prototype = {
eachChar: function(callback) {
callback({ invalidChars: "/", repeat: true });
},
regex: function() {
return "([^/]+)";
},
generate: function(params) {
return params[this.name];
}
};
function StarSegment(name) { this.name = name; }
StarSegment.prototype = {
eachChar: function(callback) {
callback({ invalidChars: "", repeat: true });
},
regex: function() {
return "(.+)";
},
generate: function(params) {
return params[this.name];
}
};
function EpsilonSegment() {}
EpsilonSegment.prototype = {
eachChar: function() {},
regex: function() { return ""; },
generate: function() { return ""; }
};
function parse(route, names, types) {
// normalize route as not starting with a "/". Recognition will
// also normalize.
if (route.charAt(0) === "/") { route = route.substr(1); }
var segments = route.split("/"), results = [];
for (var i=0, l=segments.length; i<l; i++) {
var segment = segments[i], match;
if (match = segment.match(/^:([^\/]+)$/)) {
results.push(new DynamicSegment(match[1]));
names.push(match[1]);
types.dynamics++;
} else if (match = segment.match(/^\*([^\/]+)$/)) {
results.push(new StarSegment(match[1]));
names.push(match[1]);
types.stars++;
} else if(segment === "") {
results.push(new EpsilonSegment());
} else {
results.push(new StaticSegment(segment));
types.statics++;
}
}
return results;
}
// A State has a character specification and (`charSpec`) and a list of possible
// subsequent states (`nextStates`).
//
// If a State is an accepting state, it will also have several additional
// properties:
//
// * `regex`: A regular expression that is used to extract parameters from paths
// that reached this accepting state.
// * `handlers`: Information on how to convert the list of captures into calls
// to registered handlers with the specified parameters
// * `types`: How many static, dynamic or star segments in this route. Used to
// decide which route to use if multiple registered routes match a path.
//
// Currently, State is implemented naively by looping over `nextStates` and
// comparing a character specification against a character. A more efficient
// implementation would use a hash of keys pointing at one or more next states.
function State(charSpec) {
this.charSpec = charSpec;
this.nextStates = [];
}
State.prototype = {
get: function(charSpec) {
var nextStates = this.nextStates;
for (var i=0, l=nextStates.length; i<l; i++) {
var child = nextStates[i];
var isEqual = child.charSpec.validChars === charSpec.validChars;
isEqual = isEqual && child.charSpec.invalidChars === charSpec.invalidChars;
if (isEqual) { return child; }
}
},
put: function(charSpec) {
var state;
// If the character specification already exists in a child of the current
// state, just return that state.
if (state = this.get(charSpec)) { return state; }
// Make a new state for the character spec
state = new State(charSpec);
// Insert the new state as a child of the current state
this.nextStates.push(state);
// If this character specification repeats, insert the new state as a child
// of itself. Note that this will not trigger an infinite loop because each
// transition during recognition consumes a character.
if (charSpec.repeat) {
state.nextStates.push(state);
}
// Return the new state
return state;
},
// Find a list of child states matching the next character
match: function(ch) {
// DEBUG "Processing `" + ch + "`:"
var nextStates = this.nextStates,
child, charSpec, chars;
// DEBUG " " + debugState(this)
var returned = [];
for (var i=0, l=nextStates.length; i<l; i++) {
child = nextStates[i];
charSpec = child.charSpec;
if (typeof (chars = charSpec.validChars) !== 'undefined') {
if (chars.indexOf(ch) !== -1) { returned.push(child); }
} else if (typeof (chars = charSpec.invalidChars) !== 'undefined') {
if (chars.indexOf(ch) === -1) { returned.push(child); }
}
}
return returned;
}
/** IF DEBUG
, debug: function() {
var charSpec = this.charSpec,
debug = "[",
chars = charSpec.validChars || charSpec.invalidChars;
if (charSpec.invalidChars) { debug += "^"; }
debug += chars;
debug += "]";
if (charSpec.repeat) { debug += "+"; }
return debug;
}
END IF **/
};
/** IF DEBUG
function debug(log) {
console.log(log);
}
function debugState(state) {
return state.nextStates.map(function(n) {
if (n.nextStates.length === 0) { return "( " + n.debug() + " [accepting] )"; }
return "( " + n.debug() + " <then> " + n.nextStates.map(function(s) { return s.debug() }).join(" or ") + " )";
}).join(", ")
}
END IF **/
// This is a somewhat naive strategy, but should work in a lot of cases
// A better strategy would properly resolve /posts/:id/new and /posts/edit/:id.
//
// This strategy generally prefers more static and less dynamic matching.
// Specifically, it
//
// * prefers fewer stars to more, then
// * prefers using stars for less of the match to more, then
// * prefers fewer dynamic segments to more, then
// * prefers more static segments to more
function sortSolutions(states) {
return states.sort(function(a, b) {
if (a.types.stars !== b.types.stars) { return a.types.stars - b.types.stars; }
if (a.types.stars) {
if (a.types.statics !== b.types.statics) { return b.types.statics - a.types.statics; }
if (a.types.dynamics !== b.types.dynamics) { return b.types.dynamics - a.types.dynamics; }
}
if (a.types.dynamics !== b.types.dynamics) { return a.types.dynamics - b.types.dynamics; }
if (a.types.statics !== b.types.statics) { return b.types.statics - a.types.statics; }
return 0;
});
}
function recognizeChar(states, ch) {
var nextStates = [];
for (var i=0, l=states.length; i<l; i++) {
var state = states[i];
nextStates = nextStates.concat(state.match(ch));
}
return nextStates;
}
var oCreate = Object.create || function(proto) {
function F() {}
F.prototype = proto;
return new F();
};
function RecognizeResults(queryParams) {
this.queryParams = queryParams || {};
}
RecognizeResults.prototype = oCreate({
splice: Array.prototype.splice,
slice: Array.prototype.slice,
push: Array.prototype.push,
length: 0,
queryParams: null
});
function findHandler(state, path, queryParams) {
var handlers = state.handlers, regex = state.regex;
var captures = path.match(regex), currentCapture = 1;
var result = new RecognizeResults(queryParams);
for (var i=0, l=handlers.length; i<l; i++) {
var handler = handlers[i], names = handler.names, params = {};
for (var j=0, m=names.length; j<m; j++) {
params[names[j]] = captures[currentCapture++];
}
result.push({ handler: handler.handler, params: params, isDynamic: !!names.length });
}
return result;
}
function addSegment(currentState, segment) {
segment.eachChar(function(ch) {
var state;
currentState = currentState.put(ch);
});
return currentState;
}
// The main interface
var RouteRecognizer = function() {
this.rootState = new State();
this.names = {};
};
RouteRecognizer.prototype = {
add: function(routes, options) {
var currentState = this.rootState, regex = "^",
types = { statics: 0, dynamics: 0, stars: 0 },
handlers = [], allSegments = [], name;
var isEmpty = true;
for (var i=0, l=routes.length; i<l; i++) {
var route = routes[i], names = [];
var segments = parse(route.path, names, types);
allSegments = allSegments.concat(segments);
for (var j=0, m=segments.length; j<m; j++) {
var segment = segments[j];
if (segment instanceof EpsilonSegment) { continue; }
isEmpty = false;
// Add a "/" for the new segment
currentState = currentState.put({ validChars: "/" });
regex += "/";
// Add a representation of the segment to the NFA and regex
currentState = addSegment(currentState, segment);
regex += segment.regex();
}
var handler = { handler: route.handler, names: names };
handlers.push(handler);
}
if (isEmpty) {
currentState = currentState.put({ validChars: "/" });
regex += "/";
}
currentState.handlers = handlers;
currentState.regex = new RegExp(regex + "$");
currentState.types = types;
if (name = options && options.as) {
this.names[name] = {
segments: allSegments,
handlers: handlers
};
}
},
handlersFor: function(name) {
var route = this.names[name], result = [];
if (!route) { throw new Error("There is no route named " + name); }
for (var i=0, l=route.handlers.length; i<l; i++) {
result.push(route.handlers[i]);
}
return result;
},
hasRoute: function(name) {
return !!this.names[name];
},
generate: function(name, params) {
var route = this.names[name], output = "";
if (!route) { throw new Error("There is no route named " + name); }
var segments = route.segments;
for (var i=0, l=segments.length; i<l; i++) {
var segment = segments[i];
if (segment instanceof EpsilonSegment) { continue; }
output += "/";
output += segment.generate(params);
}
if (output.charAt(0) !== '/') { output = '/' + output; }
if (params && params.queryParams) {
output += this.generateQueryString(params.queryParams, route.handlers);
}
return output;
},
generateQueryString: function(params, handlers) {
var pairs = [];
var keys = [];
for(var key in params) {
if (params.hasOwnProperty(key)) {
keys.push(key);
}
}
keys.sort();
for (var i = 0, len = keys.length; i < len; i++) {
key = keys[i];
var value = params[key];
if (value == null) {
continue;
}
var pair = key;
if (isArray(value)) {
for (var j = 0, l = value.length; j < l; j++) {
var arrayPair = key + '[]' + '=' + encodeURIComponent(value[j]);
pairs.push(arrayPair);
}
} else {
pair += "=" + encodeURIComponent(value);
pairs.push(pair);
}
}
if (pairs.length === 0) { return ''; }
return "?" + pairs.join("&");
},
parseQueryString: function(queryString) {
var pairs = queryString.split("&"), queryParams = {};
for(var i=0; i < pairs.length; i++) {
var pair = pairs[i].split('='),
key = decodeURIComponent(pair[0]),
keyLength = key.length,
isArray = false,
value;
if (pair.length === 1) {
value = 'true';
} else {
//Handle arrays
if (keyLength > 2 && key.slice(keyLength -2) === '[]') {
isArray = true;
key = key.slice(0, keyLength - 2);
if(!queryParams[key]) {
queryParams[key] = [];
}
}
value = pair[1] ? decodeURIComponent(pair[1]) : '';
}
if (isArray) {
queryParams[key].push(value);
} else {
queryParams[key] = decodeURIComponent(value);
}
}
return queryParams;
},
recognize: function(path) {
var states = [ this.rootState ],
pathLen, i, l, queryStart, queryParams = {},
isSlashDropped = false;
path = decodeURI(path);
queryStart = path.indexOf('?');
if (queryStart !== -1) {
var queryString = path.substr(queryStart + 1, path.length);
path = path.substr(0, queryStart);
queryParams = this.parseQueryString(queryString);
}
// DEBUG GROUP path
if (path.charAt(0) !== "/") { path = "/" + path; }
pathLen = path.length;
if (pathLen > 1 && path.charAt(pathLen - 1) === "/") {
path = path.substr(0, pathLen - 1);
isSlashDropped = true;
}
for (i=0, l=path.length; i<l; i++) {
states = recognizeChar(states, path.charAt(i));
if (!states.length) { break; }
}
// END DEBUG GROUP
var solutions = [];
for (i=0, l=states.length; i<l; i++) {
if (states[i].handlers) { solutions.push(states[i]); }
}
states = sortSolutions(solutions);
var state = solutions[0];
if (state && state.handlers) {
// if a trailing slash was dropped and a star segment is the last segment
// specified, put the trailing slash back
if (isSlashDropped && state.regex.source.slice(-5) === "(.+)$") {
path = path + "/";
}
return findHandler(state, path, queryParams);
}
}
};
__exports__.RouteRecognizer = RouteRecognizer;
function Target(path, matcher, delegate) {
this.path = path;
this.matcher = matcher;
this.delegate = delegate;
}
Target.prototype = {
to: function(target, callback) {
var delegate = this.delegate;
if (delegate && delegate.willAddRoute) {
target = delegate.willAddRoute(this.matcher.target, target);
}
this.matcher.add(this.path, target);
if (callback) {
if (callback.length === 0) { throw new Error("You must have an argument in the function passed to `to`"); }
this.matcher.addChild(this.path, target, callback, this.delegate);
}
return this;
}
};
function Matcher(target) {
this.routes = {};
this.children = {};
this.target = target;
}
Matcher.prototype = {
add: function(path, handler) {
this.routes[path] = handler;
},
addChild: function(path, target, callback, delegate) {
var matcher = new Matcher(target);
this.children[path] = matcher;
var match = generateMatch(path, matcher, delegate);
if (delegate && delegate.contextEntered) {
delegate.contextEntered(target, match);
}
callback(match);
}
};
function generateMatch(startingPath, matcher, delegate) {
return function(path, nestedCallback) {
var fullPath = startingPath + path;
if (nestedCallback) {
nestedCallback(generateMatch(fullPath, matcher, delegate));
} else {
return new Target(startingPath + path, matcher, delegate);
}
};
}
function addRoute(routeArray, path, handler) {
var len = 0;
for (var i=0, l=routeArray.length; i<l; i++) {
len += routeArray[i].path.length;
}
path = path.substr(len);
var route = { path: path, handler: handler };
routeArray.push(route);
}
function eachRoute(baseRoute, matcher, callback, binding) {
var routes = matcher.routes;
for (var path in routes) {
if (routes.hasOwnProperty(path)) {
var routeArray = baseRoute.slice();
addRoute(routeArray, path, routes[path]);
if (matcher.children[path]) {
eachRoute(routeArray, matcher.children[path], callback, binding);
} else {
callback.call(binding, routeArray);
}
}
}
}
RouteRecognizer.prototype.map = function(callback, addRouteCallback) {
var matcher = new Matcher();
callback(generateMatch("", matcher, this.delegate));
eachRoute([], matcher, function(route) {
if (addRouteCallback) { addRouteCallback(this, route); }
else { this.add(route); }
}, this);
};
})(window);