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 serverthis.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 serverthis.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 databasethis.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 databasethis.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 databasethis.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 documentdoc._deleted = true;return result;}// Deletes an attachment from a documentthis.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 documentreturn result;}this.bulkSave = function(docs, options) {// first prepoulate the UUIDs for new documentsvar newCount = 0for (var i = 0; i < docs.length; i++) {if (docs[i]._id == undefined)newCount++;}var newUuids = CouchDB.newUuids(docs.length);var newCount = 0for (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 jsonfor (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 databasethis.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 docthis.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("&");}