| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| /* $Rev$ $Date$ */ |
| |
| #ifndef tuscany_json_hpp |
| #define tuscany_json_hpp |
| |
| /** |
| * JSON data conversion functions. |
| */ |
| |
| #include "string.hpp" |
| #include "list.hpp" |
| #include "value.hpp" |
| #include "element.hpp" |
| #include "monad.hpp" |
| #include "../js/eval.hpp" |
| |
| namespace tuscany { |
| namespace json { |
| |
| /** |
| * Return true if a list of strings contains a JSON document. |
| */ |
| const bool isJSON(const list<string>& ls) { |
| if (isNil(ls)) |
| return false; |
| const string s = substr(car(ls), 0, 1); |
| return s == "[" || s == "{"; |
| } |
| |
| /** |
| * Consumes JSON strings and populates a JS object. |
| */ |
| failable<bool> consume(JSONParser* parser, const list<string>& ilist, const js::JSContext& cx) { |
| if (isNil(ilist)) |
| return true; |
| JSString* jstr = JS_NewStringCopyZ(cx, c_str(car(ilist))); |
| if(!JS_ConsumeJSONText(cx, parser, JS_GetStringCharsZ(cx, jstr), (uint32)JS_GetStringLength(jstr))) |
| return mkfailure<bool>("JS_ConsumeJSONText failed"); |
| return consume(parser, cdr(ilist), cx); |
| } |
| |
| /** |
| * Convert a list of strings representing a JSON document to a list of values. |
| */ |
| const failable<list<value> > readJSON(const list<string>& ilist, const js::JSContext& cx) { |
| jsval val; |
| JSONParser* parser = JS_BeginJSONParse(cx, &val); |
| if(parser == NULL) |
| return mkfailure<list<value> >("JS_BeginJSONParse failed"); |
| |
| const failable<bool> consumed = consume(parser, ilist, cx); |
| |
| if(!JS_FinishJSONParse(cx, parser, JSVAL_NULL)) |
| return mkfailure<list<value> >("JS_FinishJSONParse failed"); |
| if(!hasContent(consumed)) |
| return mkfailure<list<value> >(reason(consumed)); |
| |
| return list<value>(js::jsValToValue(val, cx)); |
| } |
| |
| /** |
| * Context passed to the JSON write callback function. |
| */ |
| template<typename R> class WriteContext { |
| public: |
| WriteContext(const lambda<R(const string&, const R)>& reduce, const R& accum, const js::JSContext& cx) : cx(cx), reduce(reduce), accum(accum) { |
| } |
| const js::JSContext& cx; |
| const lambda<R(const string&, const R)> reduce; |
| R accum; |
| }; |
| |
| /** |
| * Called by JS_Stringify to write JSON out. |
| */ |
| template<typename R> JSBool writeCallback(const jschar *buf, uint32 len, void *data) { |
| WriteContext<R>& wcx = *(static_cast<WriteContext<R>*> (data)); |
| JSString* jstr = JS_NewUCStringCopyN(wcx.cx, buf, len); |
| char* cstr = JS_EncodeString(wcx.cx, jstr); |
| const string str(cstr, JS_GetStringLength(jstr)); |
| JS_free(wcx.cx, cstr); |
| wcx.accum = wcx.reduce(str, wcx.accum); |
| return JS_TRUE; |
| } |
| |
| /** |
| * Convert a list of values to a JSON document. |
| */ |
| template<typename R> const failable<R> writeJSON(const lambda<R(const string&, const R)>& reduce, const R& initial, const list<value>& l, const js::JSContext& cx) { |
| jsval val; |
| if (js::isJSArray(l)) |
| val = OBJECT_TO_JSVAL(valuesToJSElements(JS_NewArrayObject(cx, 0, NULL), l, 0, cx)); |
| else |
| val = OBJECT_TO_JSVAL(valuesToJSProperties(JS_NewObject(cx, NULL, NULL, NULL), l, cx)); |
| |
| WriteContext<R> wcx(reduce, initial, cx); |
| if (!JS_Stringify(cx, &val, NULL, INT_TO_JSVAL(1), writeCallback<R>, &wcx)) |
| return mkfailure<R>("JS_Stringify failed"); |
| return wcx.accum; |
| } |
| |
| /** |
| * Convert a list of values to a list of strings representing a JSON document. |
| */ |
| const failable<list<string> > writeJSON(const list<value>& l, const js::JSContext& cx) { |
| const failable<list<string> > ls = writeJSON<list<string>>(rcons<string>, list<string>(), valuesToElements(elementsToValues(l)), cx); |
| if (!hasContent(ls)) |
| return ls; |
| return reverse(list<string>(content(ls))); |
| } |
| |
| /** |
| * Convert a list of function + params to a JSON-RPC request. |
| */ |
| const failable<list<string> > jsonRequest(const value& id, const value& func, const value& params, js::JSContext& cx) { |
| const list<value> r = mklist<value>(mklist<value>("id", id), mklist<value>("method", string(func)), mklist<value>("params", params)); |
| return writeJSON(valuesToElements(r), cx); |
| } |
| |
| /** |
| * Convert a value to a JSON-RPC result. |
| */ |
| const failable<list<string> > jsonResult(const value& id, const value& val, js::JSContext& cx) { |
| return writeJSON(valuesToElements(mklist<value>(mklist<value>("id", id), mklist<value>("result", val))), cx); |
| } |
| |
| /** |
| * Convert a JSON-RPC result to a value. |
| */ |
| const failable<value> jsonResultValue(const list<string>& s, js::JSContext& cx) { |
| const failable<list<value> > jsres = json::readJSON(s, cx); |
| if (!hasContent(jsres)) |
| return mkfailure<value>(reason(jsres)); |
| const list<value> rval(cadr<value>(elementsToValues(content(jsres)))); |
| const value val = cadr(rval); |
| if (isList(val) && !js::isJSArray(val)) |
| return value(mklist<value>(val)); |
| return val; |
| } |
| |
| /** |
| * Convert a JSON payload to a list of values. |
| */ |
| const list<value> jsonValues(const list<value>& e) { |
| return elementsToValues(e); |
| } |
| |
| /** |
| * Return a portable function name from a JSON-RPC function name. |
| * Strip the ".", "system." and "Service." prefixes added by some JSON-RPC clients. |
| */ |
| const string funcName(const string& f) { |
| if (length(f) > 1 && find(f, ".", 0) == 0) |
| return c_str(f) + 1; |
| if (length(f) > 7 && find(f, "system.", 0) == 0) |
| return c_str(f) + 7; |
| if (length(f) > 8 && find(f, "Service.", 0) == 0) |
| return c_str(f) + 8; |
| return f; |
| } |
| |
| /** |
| * Returns a list of param values other than the id and method args from a list |
| * of key value pairs. |
| */ |
| const list<value> queryParams(const list<list<value> >& a) { |
| if (isNil(a)) |
| return list<value>(); |
| const list<value> p = car(a); |
| if (car(p) == value("id") || car(p) == value("method")) |
| return queryParams(cdr(a)); |
| return cons(cadr(p), queryParams(cdr(a))); |
| } |
| |
| } |
| } |
| |
| #endif /* tuscany_json_hpp */ |