javascript 实现的CouchDB REST客户端接口

javascript 实现的CouchDB REST客户端接口，该接口主要有两个javascript对象构成，其中JSON接口（该接口实现用到了闭包，接口等编程技巧，可以参考学习）主要用于json解析，代码如下：

/* json2.js 2008-03-14 Public Domain No warranty expressed or implied. Use at your own risk. See http://www.JSON.org/js.html This is a reference implementation. You are free to copy, modify, or redistribute. Use your own copy. It is extremely unwise to load third party code into your pages. */ if (!this.JSON) { JSON = function() { function f(n) { // Format integers to have at least two digits. return n < 10 ? '0' + n : n; } Date.prototype.toJSON = function() { return this.getUTCFullYear() + '-' + f(this.getUTCMonth() + 1) + '-' + f(this.getUTCDate()) + 'T' + f(this.getUTCHours()) + ':' + f(this.getUTCMinutes()) + ':' + f(this.getUTCSeconds()) + 'Z'; }; var m = { // table of character substitutions '/b' : '//b', '/t' : '//t', '/n' : '//n', '/f' : '//f', '/r' : '//r', '"' : '//"', '//' : '////' }; function stringify(value, whitelist) { var a, // The array holding the partial texts. i, // The loop counter. k, // The member key. l, // Length. r = /["///x00-/x1f/x7f-/x9f]/g, v; // The member value. switch (typeof value) { case 'string': return r.test(value) ? '"' + value.replace(r, function(a) { var c = m[a]; if (c) { return c; } c = a.charCodeAt(); return '//u00' + Math.floor(c / 16).toString(16) + (c % 16).toString(16); }) + '"' : '"' + value + '"'; case 'number': return isFinite(value) ? String(value) : 'null'; case 'boolean': case 'null': return String(value); case 'object': if (!value) { return 'null'; } if (typeof value.toJSON === 'function') { return stringify(value.toJSON()); } a = []; if (typeof value.length === 'number' && !(value.propertyIsEnumerable('length'))) { l = value.length; for (i = 0; i < l; i += 1) { a.push(stringify(value[i], whitelist) || 'null'); } return '[' + a.join(',') + ']'; } if (whitelist) { l = whitelist.length; for (i = 0; i < l; i += 1) { k = whitelist[i]; if (typeof k === 'string') { v = stringify(value[k], whitelist); if (v) { a.push(stringify(k) + ':' + v); } } } } else { for (k in value) { if (typeof k === 'string') { v = stringify(value[k], whitelist); if (v) { a.push(stringify(k) + ':' + v); } } } } return '{' + a.join(',') + '}'; } } return { stringify : stringify, parse : function(text, filter) { var j; function walk(k, v) { var i, n; if (v && typeof v === 'object') { for (i in v) { if (Object.prototype.hasOwnProperty.apply(v, [ i ])) { n = walk(i, v[i]); if (n !== undefined) { v[i] = n; } else { delete v[i]; } } } } return filter(k, v); } if (/^[/],:{}/s]*$/ .test(text .replace(///["////bfnrtu]/g, '@') .replace( /"[^"///n/r]*"|true|false|null|-?/d+(?:/./d*)?(?:[eE][+/-]?/d+)?/g, ']') .replace(/(?:^|:|,)(?:/s*/[)+/g, ''))) { j = eval('(' + text + ')'); return typeof filter === 'function' ? walk('', j) : j; } throw new SyntaxError('parseJSON'); } }; }(); }

 

另一个接口为CouchDB，该接口为一个javascript对象，该对象实现了couchdb大部分客户端接口，按照REST风格格式实现了增，删，查，改等功能，通过封装XMLHttpRequest对象与服务端通信（在couchdb的js客户端中还有jQuery实现REST接口的，可以查看源码）

代码如下：

 

// Licensed 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. // A simple class to represent a database. Uses XMLHttpRequest to interface with // the CouchDB server. function CouchDB(name, httpHeaders) { this.name = name; this.uri = "/" + encodeURIComponent(name) + "/"; // The XMLHttpRequest object from the most recent request. Callers can // use this to check result http status and headers. this.last_req = null; this.request = function(method, uri, requestOptions) { requestOptions = requestOptions || {} requestOptions.headers = combine(requestOptions.headers, httpHeaders) return CouchDB.request(method, uri, requestOptions); } // Creates the database on the server this.createDb = function() { this.last_req = this.request("PUT", this.uri); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } // Deletes the database on the server this.deleteDb = function() { this.last_req = this.request("DELETE", this.uri); if (this.last_req.status == 404) return false; CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } // Save a document to the database this.save = function(doc, options) { if (doc._id == undefined) doc._id = CouchDB.newUuids(1)[0]; this.last_req = this.request("PUT", this.uri + encodeURIComponent(doc._id) + encodeOptions(options), { body : JSON.stringify(doc) }); CouchDB.maybeThrowError(this.last_req); var result = JSON.parse(this.last_req.responseText); doc._rev = result.rev; return result; } // Open a document from the database this.open = function(docId, options) { this.last_req = this.request("GET", this.uri + encodeURIComponent(docId) + encodeOptions(options)); if (this.last_req.status == 404) return null; CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } // Deletes a document from the database this.deleteDoc = function(doc) { this.last_req = this.request("DELETE", this.uri + encodeURIComponent(doc._id) + "?rev=" + doc._rev); CouchDB.maybeThrowError(this.last_req); var result = JSON.parse(this.last_req.responseText); doc._rev = result.rev; // record rev in input document doc._deleted = true; return result; } // Deletes an attachment from a document this.deleteDocAttachment = function(doc, attachment_name) { this.last_req = this.request("DELETE", this.uri + encodeURIComponent(doc._id) + "/" + attachment_name + "?rev=" + doc._rev); CouchDB.maybeThrowError(this.last_req); var result = JSON.parse(this.last_req.responseText); doc._rev = result.rev; // record rev in input document return result; } this.bulkSave = function(docs, options) { // first prepoulate the UUIDs for new documents var newCount = 0 for (var i = 0; i < docs.length; i++) { if (docs[i]._id == undefined) newCount++; } var newUuids = CouchDB.newUuids(docs.length); var newCount = 0 for (var i = 0; i < docs.length; i++) { if (docs[i]._id == undefined) docs[i]._id = newUuids.pop(); } var json = { "docs" : docs }; // put any options in the json for (var option in options) { json[option] = options[option]; } this.last_req = this.request("POST", this.uri + "_bulk_docs", { body : JSON.stringify(json) }); if (this.last_req.status == 417) { return { errors : JSON.parse(this.last_req.responseText) }; } else { CouchDB.maybeThrowError(this.last_req); var results = JSON.parse(this.last_req.responseText); for (var i = 0; i < docs.length; i++) { if (results[i].rev) docs[i]._rev = results[i].rev; } return results; } } this.ensureFullCommit = function() { this.last_req = this.request("POST", this.uri + "_ensure_full_commit"); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } // Applies the map function to the contents of database and returns the // results. this.query = function(mapFun, reduceFun, options, keys, language) { var body = { language : language || "javascript" }; if (keys) { body.keys = keys; } if (typeof(mapFun) != "string") mapFun = mapFun.toSource ? mapFun.toSource() : "(" + mapFun.toString() + ")"; body.map = mapFun; if (reduceFun != null) { if (typeof(reduceFun) != "string") reduceFun = reduceFun.toSource ? reduceFun.toSource() : "(" + reduceFun.toString() + ")"; body.reduce = reduceFun; } if (options && options.options != undefined) { body.options = options.options; delete options.options; } this.last_req = this.request("POST", this.uri + "_temp_view" + encodeOptions(options), { headers : { "Content-Type" : "application/json" }, body : JSON.stringify(body) }); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } this.view = function(viewname, options, keys) { var viewParts = viewname.split('/'); var viewPath = this.uri + "_design/" + viewParts[0] + "/_view/" + viewParts[1] + encodeOptions(options); if (!keys) { this.last_req = this.request("GET", viewPath); } else { this.last_req = this.request("POST", viewPath, { headers : { "Content-Type" : "application/json" }, body : JSON.stringify({ keys : keys }) }); } if (this.last_req.status == 404) return null; CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } // gets information about the database this.info = function() { this.last_req = this.request("GET", this.uri); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } // gets information about a design doc this.designInfo = function(docid) { this.last_req = this.request("GET", this.uri + docid + "/_info"); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } this.viewCleanup = function() { this.last_req = this.request("POST", this.uri + "_view_cleanup"); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } this.allDocs = function(options, keys) { if (!keys) { this.last_req = this.request("GET", this.uri + "_all_docs" + encodeOptions(options)); } else { this.last_req = this.request("POST", this.uri + "_all_docs" + encodeOptions(options), { headers : { "Content-Type" : "application/json" }, body : JSON.stringify({ keys : keys }) }); } CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } this.designDocs = function() { return this.allDocs({ startkey : "_design", endkey : "_design0" }); }; this.allDocsBySeq = function(options, keys) { var req = null; if (!keys) { req = this.request("GET", this.uri + "_all_docs_by_seq" + encodeOptions(options)); } else { req = this.request("POST", this.uri + "_all_docs_by_seq" + encodeOptions(options), { headers : { "Content-Type" : "application/json" }, body : JSON.stringify({ keys : keys }) }); } CouchDB.maybeThrowError(req); return JSON.parse(req.responseText); } this.compact = function() { this.last_req = this.request("POST", this.uri + "_compact"); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } this.setDbProperty = function(propId, propValue) { this.last_req = this.request("PUT", this.uri + propId, { body : JSON.stringify(propValue) }); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } this.getDbProperty = function(propId) { this.last_req = this.request("GET", this.uri + propId); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } this.setAdmins = function(adminsArray) { this.last_req = this.request("PUT", this.uri + "_admins", { body : JSON.stringify(adminsArray) }); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } this.getAdmins = function() { this.last_req = this.request("GET", this.uri + "_admins"); CouchDB.maybeThrowError(this.last_req); return JSON.parse(this.last_req.responseText); } // Convert a options object to an url query string. // ex: {key:'value',key2:'value2'} becomes '?key="value"&key2="value2"' function encodeOptions(options) { var buf = [] if (typeof(options) == "object" && options !== null) { for (var name in options) { if (!options.hasOwnProperty(name)) continue; var value = options[name]; if (name == "key" || name == "startkey" || name == "endkey") { value = toJSON(value); } buf.push(encodeURIComponent(name) + "=" + encodeURIComponent(value)); } } if (!buf.length) { return ""; } return "?" + buf.join("&"); } function toJSON(obj) { return obj !== null ? JSON.stringify(obj) : null; } function combine(object1, object2) { if (!object2) return object1; if (!object1) return object2; for (var name in object2) object1[name] = object2[name]; return object1; } } // this is the XMLHttpRequest object from last request made by the following // CouchDB.* functions (except for calls to request itself). // Use this from callers to check HTTP status or header values of requests. CouchDB.last_req = null; CouchDB.login = function(username, password) { CouchDB.last_req = CouchDB.request("POST", "/_session", { headers : { "Content-Type" : "application/x-www-form-urlencoded", "X-CouchDB-WWW-Authenticate" : "Cookie" }, body : "username=" + encodeURIComponent(username) + "&password=" + encodeURIComponent(password) }); return JSON.parse(CouchDB.last_req.responseText); } CouchDB.logout = function() { CouchDB.last_req = CouchDB.request("DELETE", "/_session", { headers : { "Content-Type" : "application/x-www-form-urlencoded", "X-CouchDB-WWW-Authenticate" : "Cookie" } }); return JSON.parse(CouchDB.last_req.responseText); } CouchDB.createUser = function(username, password, email, roles, basicAuth) { var roles_str = "" if (roles) { for (var i = 0; i < roles.length; i++) { roles_str += "&roles=" + encodeURIComponent(roles[i]); } } var headers = { "Content-Type" : "application/x-www-form-urlencoded" }; if (basicAuth) { headers['Authorization'] = basicAuth } else { headers['X-CouchDB-WWW-Authenticate'] = 'Cookie'; } CouchDB.last_req = CouchDB.request("POST", "/_user/", { headers : headers, body : "username=" + encodeURIComponent(username) + "&password=" + encodeURIComponent(password) + "&email=" + encodeURIComponent(email) + roles_str }); return JSON.parse(CouchDB.last_req.responseText); } CouchDB.updateUser = function(username, email, roles, password, old_password) { var roles_str = "" if (roles) { for (var i = 0; i < roles.length; i++) { roles_str += "&roles=" + encodeURIComponent(roles[i]); } } var body = "email=" + encodeURIComponent(email) + roles_str; if (typeof(password) != "undefined" && password) body += "&password=" + password; if (typeof(old_password) != "undefined" && old_password) body += "&old_password=" + old_password; CouchDB.last_req = CouchDB.request("PUT", "/_user/" + encodeURIComponent(username), { headers : { "Content-Type" : "application/x-www-form-urlencoded", "X-CouchDB-WWW-Authenticate" : "Cookie" }, body : body }); return JSON.parse(CouchDB.last_req.responseText); } CouchDB.allDbs = function() { CouchDB.last_req = CouchDB.request("GET", "/_all_dbs"); CouchDB.maybeThrowError(CouchDB.last_req); return JSON.parse(CouchDB.last_req.responseText); } CouchDB.allDesignDocs = function() { var ddocs = {}, dbs = CouchDB.allDbs(); for (var i = 0; i < dbs.length; i++) { var db = new CouchDB(dbs[i]); ddocs[dbs[i]] = db.designDocs(); }; return ddocs; }; CouchDB.getVersion = function() { CouchDB.last_req = CouchDB.request("GET", "/"); CouchDB.maybeThrowError(CouchDB.last_req); return JSON.parse(CouchDB.last_req.responseText).version; } CouchDB.replicate = function(source, target, rep_options) { rep_options = rep_options || {}; var headers = rep_options.headers || {}; CouchDB.last_req = CouchDB.request("POST", "/_replicate", { headers : headers, body : JSON.stringify({ source : source, target : target }) }); CouchDB.maybeThrowError(CouchDB.last_req); return JSON.parse(CouchDB.last_req.responseText); } CouchDB.newXhr = function() { if (typeof(XMLHttpRequest) != "undefined") { return new XMLHttpRequest(); } else if (typeof(ActiveXObject) != "undefined") { return new ActiveXObject("Microsoft.XMLHTTP"); } else { throw new Error("No XMLHTTPRequest support detected"); } } CouchDB.request = function(method, uri, options) { options = options || {}; var req = CouchDB.newXhr(); req.open(method, uri, false); if (options.headers) { var headers = options.headers; for (var headerName in headers) { if (!headers.hasOwnProperty(headerName)) continue; req.setRequestHeader(headerName, headers[headerName]); } } req.send(options.body || ""); return req; } CouchDB.requestStats = function(module, key, test) { var query_arg = ""; if (test !== null) { query_arg = "?flush=true"; } var stat = CouchDB.request("GET", "/_stats/" + module + "/" + key + query_arg).responseText; return JSON.parse(stat)[module][key]; } CouchDB.uuids_cache = []; CouchDB.newUuids = function(n) { if (CouchDB.uuids_cache.length >= n) { var uuids = CouchDB.uuids_cache.slice(CouchDB.uuids_cache.length - n); if (CouchDB.uuids_cache.length - n == 0) { CouchDB.uuids_cache = []; } else { CouchDB.uuids_cache = CouchDB.uuids_cache.slice(0, CouchDB.uuids_cache.length - n); } return uuids; } else { CouchDB.last_req = CouchDB.request("GET", "/_uuids?count=" + (100 + n)); CouchDB.maybeThrowError(CouchDB.last_req); var result = JSON.parse(CouchDB.last_req.responseText); CouchDB.uuids_cache = CouchDB.uuids_cache.concat(result.uuids.slice(0, 100)); return result.uuids.slice(100); } } CouchDB.maybeThrowError = function(req) { if (req.status >= 400) { try { var result = JSON.parse(req.responseText); } catch (ParseError) { var result = { error : "unknown", reason : req.responseText }; } throw result; } } CouchDB.params = function(options) { options = options || {}; var returnArray = []; for (var key in options) { var value = options[key]; returnArray.push(key + "=" + value); } return returnArray.join("&"); }