1/*==================================================
2 *  Simile Ajax API
3 *
4 *  Include this file in your HTML file as follows:
5 *
6 *    <script src="http://simile.mit.edu/ajax/api/simile-ajax-api.js" type="text/javascript"></script>
7 *
8 *==================================================
9 */
10
11if (typeof SimileAjax == "undefined") {
12    var SimileAjax = {
13        loaded:                 false,
14        loadingScriptsCount:    0,
15        error:                  null,
16        params:                 { bundle:"true" }
17    };
18
19    SimileAjax.Platform = new Object();
20        /*
21            HACK: We need these 2 things here because we cannot simply append
22            a <script> element containing code that accesses SimileAjax.Platform
23            to initialize it because IE executes that <script> code first
24            before it loads ajax.js and platform.js.
25        */
26
27    var getHead = function(doc) {
28        return doc.getElementsByTagName("head")[0];
29    };
30
31    SimileAjax.findScript = function(doc, substring) {
32        var heads = doc.documentElement.getElementsByTagName("head");
33        for (var h = 0; h < heads.length; h++) {
34            var node = heads[h].firstChild;
35            while (node != null) {
36                if (node.nodeType == 1 && node.tagName.toLowerCase() == "script") {
37                    var url = node.src;
38                    var i = url.indexOf(substring);
39                    if (i >= 0) {
40                        return url;
41                    }
42                }
43                node = node.nextSibling;
44            }
45        }
46        return null;
47    };
48    SimileAjax.includeJavascriptFile = function(doc, url, onerror, charset) {
49        onerror = onerror || "";
50        if (doc.body == null) {
51            try {
52                var q = "'" + onerror.replace( /'/g, '&apos' ) + "'"; // "
53                doc.write("<script src='" + url + "' onerror="+ q +
54                          (charset ? " charset='"+ charset +"'" : "") +
55                          " type='text/javascript'>"+ onerror + "</script>");
56                return;
57            } catch (e) {
58                // fall through
59            }
60        }
61
62        var script = doc.createElement("script");
63        if (onerror) {
64            try { script.innerHTML = onerror; } catch(e) {}
65            script.setAttribute("onerror", onerror);
66        }
67        if (charset) {
68            script.setAttribute("charset", charset);
69        }
70        script.type = "text/javascript";
71        script.language = "JavaScript";
72        script.src = url;
73        return getHead(doc).appendChild(script);
74    };
75    SimileAjax.includeJavascriptFiles = function(doc, urlPrefix, filenames) {
76        for (var i = 0; i < filenames.length; i++) {
77            SimileAjax.includeJavascriptFile(doc, urlPrefix + filenames[i]);
78        }
79        SimileAjax.loadingScriptsCount += filenames.length;
80        SimileAjax.includeJavascriptFile(doc, SimileAjax.urlPrefix + "scripts/signal.js?" + filenames.length);
81    };
82    SimileAjax.includeCssFile = function(doc, url) {
83        if (doc.body == null) {
84            try {
85                doc.write("<link rel='stylesheet' href='" + url + "' type='text/css'/>");
86                return;
87            } catch (e) {
88                // fall through
89            }
90        }
91
92        var link = doc.createElement("link");
93        link.setAttribute("rel", "stylesheet");
94        link.setAttribute("type", "text/css");
95        link.setAttribute("href", url);
96        getHead(doc).appendChild(link);
97    };
98    SimileAjax.includeCssFiles = function(doc, urlPrefix, filenames) {
99        for (var i = 0; i < filenames.length; i++) {
100            SimileAjax.includeCssFile(doc, urlPrefix + filenames[i]);
101        }
102    };
103
104    /**
105     * Append into urls each string in suffixes after prefixing it with urlPrefix.
106     * @param {Array} urls
107     * @param {String} urlPrefix
108     * @param {Array} suffixes
109     */
110    SimileAjax.prefixURLs = function(urls, urlPrefix, suffixes) {
111        for (var i = 0; i < suffixes.length; i++) {
112            urls.push(urlPrefix + suffixes[i]);
113        }
114    };
115
116    /**
117     * Parse out the query parameters from a URL
118     * @param {String} url    the url to parse, or location.href if undefined
119     * @param {Object} to     optional object to extend with the parameters
120     * @param {Object} types  optional object mapping keys to value types
121     *        (String, Number, Boolean or Array, String by default)
122     * @return a key/value Object whose keys are the query parameter names
123     * @type Object
124     */
125    SimileAjax.parseURLParameters = function(url, to, types) {
126        to = to || {};
127        types = types || {};
128
129        if (typeof url == "undefined") {
130            url = location.href;
131        }
132        var q = url.indexOf("?");
133        if (q < 0) {
134            return to;
135        }
136        url = (url+"#").slice(q+1, url.indexOf("#")); // toss the URL fragment
137
138        var params = url.split("&"), param, parsed = {};
139        var decode = window.decodeURIComponent || unescape;
140        for (var i = 0; param = params[i]; i++) {
141            var eq = param.indexOf("=");
142            var name = decode(param.slice(0,eq));
143            var old = parsed[name];
144            if (typeof old == "undefined") {
145                old = [];
146            } else if (!(old instanceof Array)) {
147                old = [old];
148            }
149            parsed[name] = old.concat(decode(param.slice(eq+1)));
150        }
151        for (var i in parsed) {
152            if (!parsed.hasOwnProperty(i)) continue;
153            var type = types[i] || String;
154            var data = parsed[i];
155            if (!(data instanceof Array)) {
156                data = [data];
157            }
158            if (type === Boolean && data[0] == "false") {
159                to[i] = false; // because Boolean("false") === true
160            } else {
161                to[i] = type.apply(this, data);
162            }
163        }
164        return to;
165    };
166
167    (function() {
168        var javascriptFiles = [
169            "jquery-1.2.6.min.js",
170            "platform.js",
171            "debug.js",
172            "xmlhttp.js",
173            "json.js",
174            "dom.js",
175            "graphics.js",
176            "date-time.js",
177            "string.js",
178            "html.js",
179            "data-structure.js",
180            "units.js",
181
182            "ajax.js",
183            "history.js",
184            "window-manager.js"
185        ];
186        var cssFiles = [
187            "graphics.css"
188        ];
189
190        if (typeof SimileAjax_urlPrefix == "string") {
191            SimileAjax.urlPrefix = SimileAjax_urlPrefix;
192        } else {
193            var url = SimileAjax.findScript(document, "simile-ajax-api.js");
194            if (url == null) {
195                SimileAjax.error = new Error("Failed to derive URL prefix for Simile Ajax API code files");
196                return;
197            }
198
199            SimileAjax.urlPrefix = url.substr(0, url.indexOf("simile-ajax-api.js"));
200        }
201
202        SimileAjax.parseURLParameters(url, SimileAjax.params, {bundle:Boolean});
203        if (SimileAjax.params.bundle) {
204            SimileAjax.includeJavascriptFiles(document, SimileAjax.urlPrefix, [ "simile-ajax-bundle.js" ]);
205        } else {
206            SimileAjax.includeJavascriptFiles(document, SimileAjax.urlPrefix + "scripts/", javascriptFiles);
207        }
208        SimileAjax.includeCssFiles(document, SimileAjax.urlPrefix + "styles/", cssFiles);
209
210        SimileAjax.loaded = true;
211    })();
212}
213