As covered in Handler for cScriptDbCom requests, a handler will deal with REST requests from VBA API for scriptDB.
In addition to a reference to the dispatcher library, it needs a reference to a GAS LIbrary for the appropriate class, which can be found at resource
ML7nE0jnmV4tCqTYKNkIykai_d-phDA33,
and typically will be constructed like this.
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var c = new scriptDbCom.cScriptDbCom ( e,scriptDbDispatch.getDb(e.parameter.library),whatsAllowed); |
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scriptDbCom handler
The Code
ML7nE0jnmV4tCqTYKNkIykai_d-phDA33
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/** * create a cScriptDbCom instance * @param {object} e arguments passed to the web app * @param {ScriptDBInstance} repoDb the scriptDB to operate on * @param {[String]} allowedOperations list of operations that can be done. default ['delete','create','update','query','count','getbyid'] * return {cScriptDbCom} a new cScriptDbCom object */ function cScriptDbCom (e,repoDb,allowedOperations) { var debugLogger = null; var HANDLERAPI = 'GASv0102'; var QUERYLIMIT = 50; var self = this; var pdb = repoDb; var pResult; var pBatch = {method:null, queue:[], status:'good'}; var pAllowed = allowedOperations || ['delete','create','update','query','count','getbyid']; /** * return results of latest request * return {object} latest request result */ self.getResult = function() { return pResult; } /** * @param {object} e arguments passed to the web app * return {object} defaults added to given parameters */ self.argDefaults = function (e) { e = e || {}; e.parameter = e.parameter || {}; e.parameter.class = e.parameter.class || "xLiberation"; e.parameter.debug = e.parameter.hasOwnProperty("debug") ? e.parameter.debug : 1; e.parameter.clientApi = e.parameter.api || 'unknown'; return e; } //set up the defaults var eArgs = self.argDefaults(e); /** * return {object} the latest args, including the defaults */ self.getArgs = function () { return eArgs; } self.getParam = function(prop) { return self.getArgs().parameter[prop]; } self.isAllowed = function(access) { // check if something is allowed or not if (pAllowed.indexOf(access) > -1) { return true; } else { pResult.status ='bad'; pResult.error = access + " operation not allowed on this db"; return false; } } /** * return {object} the latest results, following a query request */ self.handleQuery = function () { // the query here will return only up to the Limit. If you need more, you need to manage calls using skip & limit // setup the query, adding the silo for this class pResult = {status:'good',count:0,results:[]}; var e = this.getArgs(); var q = this.querySet( e.parameter.where ? JSON.parse(e.parameter.where) : null ); if (e.parameter.count) { // this is a simple count pResult.handler = "count"; if (self.isAllowed(pResult.handler)) { pResult.count=pdb.count(q); } } else if (e.parameter.objectid) { pResult.handler = "getbyid"; if (self.isAllowed(pResult.handler)) { // get by its object ID var record = pdb.load(e.parameter.objectid); if (record) { pResult.count = 1; record.objectId = record.getId(); delete record.siloId; pResult.results= [record] ; } else { pResult.status = 'bad'; pResult.error = 'Could not find object with id:' + e.parameter.objectid; } } } else { pResult.handler = "query"; if (self.isAllowed(pResult.handler)) { var dbResult = pdb.query (q) .limit(e.parameter.hasOwnProperty("limit") ? e.parameter.limit : QUERYLIMIT) .startAt(e.parameter.skip || 0 ); // setup convenience count var results = []; pResult.count = dbResult.getSize(); // return the results while (dbResult.hasNext()) { var o = dbResult.next(); o.objectId = o.getId(); delete o.siloId; results.push(o); } pResult.results = results; } } return pResult; } /** * find the requested object by its object ID in the queue of things in a batch. All Posts are batched. * @param {String} id arguments passed to the web app * return {Object} the batch queue item */ self.findInQueue = function (id) { for (var i=0; i < pBatch.queue.length ; i++) { if (pBatch.queue[i].objectId === id) return pBatch.queue[i]; } return null; } self.getIds = function () { var ids = []; for (var i =0; i <pBatch.queue.length; i++) { var id = pBatch.queue[i].objectId; if (!id) { pResult = {status:'bad', error: 'missing objectID from batched post request',results:{}}; return null; } ids.push(id); } return ids; } /** * record access - note that per policy, silo will expire , and message will be deleted 24 hours after creation */ self.getStamps = function (record) { if (!record.stamps) record.stamps = {}; return record.stamps; }; self.stamp = function (record,prop) { var s = self.getStamps(record); s[prop] = new Date().getTime(); s.api = self.getParam('clientApi'); s.handler = HANDLERAPI; return self; }; /** * since we are using batching, this would flush out the queued request * return {Object} the flush result */ self.flush = function() { var results; pResult = {status:'good',results:[],handler:"flush"}; function breakingBad (resultObject,theError,theResults) { resultObject.error = theError; resultObject.results = theResults; resultObject.status = 'bad'; return resultObject; } // the method selects the activity if (pBatch.queue.length ) { if (pBatch.method === 'POST') { // this is a create - simply save the result try { pBatch.queue.forEach( function (rec) { self.stamp(rec,"created")}); results = pdb.saveBatch(pBatch.queue,false); } catch(err) { return breakingBad (pResult, err, results); } } else if (pBatch.method === 'PUT') { // we can get the current values by objectId var ids = self.getIds(); if (!ids) return pResult; try { var records = pdb.load (ids); } catch(err) { return breakingBad (pResult, err, records); } // did we get any? if(records) { try { // go through what we got var targetId; for (var i = 0; i < records.length; i++ ) { targetId=records[i].getId(); // find this object in the batch update list var q = self.findInQueue (targetId); if (q) { for ( var k in q) { records[i][k] = q[k]; } if (records[i].hasOwnProperty("objectId")) { delete records[i].objectId; } self.stamp(records[i],"updated"); } } } catch (err) { return breakingBad (pResult, 'trying to get objectId for postData:' + err + 'id-' + targetId, records); } // now save all these changes as a batch try { results = pdb.saveBatch (records,false); if (!pdb.allOk(results)) { return breakingBad (pResult, "Batch save failure" , results); } } catch(err){ return breakingBad (pResult , err, records); } } } else if (pBatch.method === 'DELETE') { var ids = self.getIds(); if (!ids) return pResult; // delete is pretty straightforward by ID try { results = pdb.removeByIdBatch(ids, false); } catch(err){ return breakingBad (pResult , 'error removing from batches:'+err , results); } } else { return breakingBad (pResult , 'unknown method in batch operation:' + pBatch.method , []); } if (!pdb.allOk(results)) { return breakingBad (pResult , "Failed to complete all batch operations" , []) } else { pBatch.queue = []; } } return pResult; } /** * handle a post request from the app * return {Object} the flush result */ self.handlePost = function() { var p = self.getPostData(); if (!p) { pResult = {status:'bad', error:'no postdata provided in post request', results:[], count:0}; return pResult; } pResult = {status:'good',count:p.requests.length,results:[],postData:p}; // posts are always batched up, and follow the same form as parse.com API // {requests:[ {body:{},path:class,method:'POST'(create)|'PUT'(update)|'DELETE'(delete)},...] for ( var i = 0; i < p.requests.length ; i++ ) { var method = p.requests[i].method; pResult.handler = method; if (pBatch.method != method) { if (self.flush().status !='good') return pResult; } if (self.isAllowed( method === "POST" ? 'create' : (method === "DELETE" ? 'delete' :(method === "PUT" ? 'update':method)))) { pBatch.queue.push(self.querySet(p.requests[i].body,p.requests[i].path)); pBatch.method = method; } else { return pResult; } } return self.flush(); } /** * get the data the web app posted * return {Object} the post Data */ self.getPostData = function () { var data; // this is when a post is not possible, and the post data has been sent as an argument if (eArgs.parameter.postdata) { data = JSON.parse(e.parameter.postdata); } else { data = (e.postData && e.postData.contents) ? JSON.parse(e.postData.contents) : null; } return data; } /** * get the class that applies to the this instance * return {String} the class */ self.getClass = function () { return eArgs.parameter.class ; } /** * get the request type * return {String} the class */ self.getRequestType = function () { return eArgs.parameter.method || eArgs.requestType ; } /** * merge the query object, with the silo that this class is held in * return {Object} the query we need to make */ self.querySet = function (ob,optClass) { var ob = ob || {}; ob.siloId = optClass || this.getClass(); return ob; } /** * handle the web apps request * return {Object} the query we need to make */ self.requestResult = function () { if (this.getRequestType() === "POST") { this.handlePost(); } else if (this.getRequestType()=== "GET") { this.handleQuery(); } if (this.getArgs().debug) { pResult.debug = eArgs; } return pResult; } } function makeContent(e,type,allowed,dispatcher) { e.requestType = type; var c = new cScriptDbCom ( e,dispatcher,allowed); var content = JSON.stringify(c.requestResult()); return e.parameter.callback ? e.parameter.callback + "(" + content + ");" : content; } |
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