Files
gf-core/src/server/gf-server-jsapi.js
2008-12-05 19:08:58 +00:00

123 lines
3.3 KiB
JavaScript

var gf = new Object();
var pgf_base_url = "pgf";
gf.grammars = function (callback) {
gf.httpGetJSONP(pgf_base_url, callback);
};
gf.grammar = function (grammar, callback) {
gf.callFunction(grammar, "", [], callback);
};
gf.parse = function (grammar,input,from,cat,callback) {
var args = [];
args["input"] = input;
args["from"] = from;
args["cat"] = cat;
gf.callFunction(grammar, "parse", args, callback);
};
gf.complete = function (grammar,input,from,cat,callback) {
var args = [];
args["input"] = input;
args["from"] = from;
args["cat"] = cat;
gf.callFunction(grammar, "complete", args, callback);
};
gf.linearize = function (grammar,tree,to,callback) {
var args = [];
args["tree"] = tree;
args["to"] = to;
gf.callFunction(grammar, "linearize", args, callback);
};
gf.random = function (grammar,cat,limit,callback) {
var args = [];
args["cat"] = cat;
args["limit"] = limit;
gf.callFunction(grammar, "random", args, callback);
};
gf.translate = function (grammar,input,from,to,cat,callback) {
var args = [];
args["input"] = input;
args["from"] = from;
args["to"] = to;
args["cat"] = cat;
gf.callFunction(grammar, "translate", args, callback);
};
gf.callFunction = function (grammar, fun, args, callback) {
var query = "";
for (var i in args) {
query += (query == "") ? "?" : "&";
query += i + "=" + encodeURIComponent(args[i]);
}
var url = pgf_base_url + "/" + grammar +"/" + fun + query;
// FIXME: if same domain, use gf.httpGetText
gf.httpGetJSONP(url, callback);
}
gf.httpGetJSONP = function (url, callback) {
var script = document.createElement("script");
if (!window.jsonCallbacks) {
window.jsonCallbacks = new Array();
}
var callbackIndex = window.jsonCallbacks.length;
window.jsonCallbacks.push(function (output) {
// get rid of the script tag
document.getElementsByTagName("head")[0].removeChild(script);
// let this function be garbage-collected
window.jsonCallbacks[callbackIndex] = null;
// shrink the array if possible
while (window.jsonCallbacks.length > 0 && window.jsonCallbacks[window.jsonCallbacks.length-1] == null) {
window.jsonCallbacks.pop();
}
callback(output);
});
var callbackName = "jsonCallbacks[" + callbackIndex + "]";
var questionMarkPos = url.indexOf("?");
if (questionMarkPos > -1) {
url += (questionMarkPos < url.length-1) ? "&" : "";
} else {
url += "?";
}
url += "jsonp=" + callbackName;
script.setAttribute("src", url);
script.setAttribute("type", "text/javascript");
document.getElementsByTagName("head")[0].appendChild(script);
};
gf.httpGetText = function (url, callback) {
var XMLHttpRequestObject = false;
if (window.XMLHttpRequest) {
XMLHttpRequestObject = new XMLHttpRequest();
} else if (window.ActiveXObject) {
XMLHttpRequestObject = new ActiveXObject("Microsoft.XMLHTTP");
}
if (XMLHttpRequestObject) {
XMLHttpRequestObject.open("GET", url);
XMLHttpRequestObject.onreadystatechange = function () {
if (XMLHttpRequestObject.readyState == 4 && XMLHttpRequestObject.status == 200) {
callback(XMLHttpRequestObject.responseText);
delete XMLHttpRequestObject;
XMLHttpRequestObject = null;
}
}
XMLHttpRequestObject.send(null);
}
};
gf.readJSON = function (text) {
return eval("("+text+")");
};