App Maker has default validations and regular expression validation which will highlight the fields once the error occurs.
We have requirement to do custom validations to check duplicate records in models. Is there any function to check the validation or do we need to do any script?
The best way to avoid data duplication will be enforcing 'unique' constraint for your tables using Cloud SQL.
In case you don't want to use Cloud SQL and want to go with Drive Tables you can emulate unique constraint manually using locks, queries and model events:
// onCreate model event (actually it is onBeforeCreate)
// this events accepts about-to-create record as parameter
var lock = LockService.getScriptLock();
lock.waitLock(5000);
var query = app.models.MyModel.newQuery();
query.filters.SomeField._equals = record.SomeField;
var records = query.run();
if (records.length > 0) {
throw new Error('Record with SomeField value equal to ' + record.SomeField +
' already exists.');
}
lock.releaseLock();
You need lock here to prevent other threads concurrently creating records that will violate your unique constraint.
Then you can handle the error on UI in createItem function callback:
// create button onClick handler
widget.datasource.createItem({
success: function(record) {
// TODO
},
failure: function(error) {
// TODO
}
});
Related
Using GoogleAppMaker how to create a data source from google contacts. There is an employee HR example app but I want to similarly manage contacts (add, modify, delete) and use select criteria.
At this time this task is not trivial in App Maker and it is pretty much generic. We can change question wording to CRUD operations with 3rd party datasources. Let's break it into smaller parts and address them separately.
Read/list contacts
This task is relatively easy. You need to use Calculated Model to proxy Apps Scripts Contacts API response. Once you create model with subset of fields from the Contact response you can create datasource for the model and bind it to List or Table widget. You can also try to find some inspiration in Calculated Model Sample.
// Server side script
function getContacts_() {
var contacts = ContactsApp.getContacts();
var records = contacts.map(function(contact) {
var record = app.models.Contact.newRecord();
record.FirstName = contact.getGivenName();
record.LastName = contact.getFamilyName();
var companies = contact.getCompanies();
if (companies.length > 0) {
var company = companies[0];
record.Organization = company.getCompanyName();
record.Title = company.getJobTitle();
}
var emails = contact.getEmails();
if (emails.length > 0) {
record.Email = emails[0].getAddress();
}
var phones = contact.getPhones();
if (phones.length > 0) {
record.Phone = phones[0].getPhoneNumber();
}
return record;
});
return records;
}
Create/Update/Delete
Since Calculated Models have some limitations, we need to turn on our imagination to create, update and delete records from their datasources. The basic strategy will be calling server side scripts for CUD operations in response to user actions on client side. To get user's input from UI we will need to utilize page's Custom Properties, one property for each Contact field:
Here are some snippets that should explain the idea
Create
// Client script
function onSubmitContactClick(submitButton) {
var props = submitButton.root.properties;
var contact = {
FirstName: props.FirstName,
LastName: props.LastName,
Organization: props.Organization,
...
};
google.script.run
.withSuccessHandler(function() {
// Most likely we'll need to navigate user back to the
// page with contacts list and reload its datasource
// to reflect recent changes, because our `CUD` operations
// are fully detached from the list datasource
app.showPage(app.pages.Contacts);
app.datasources.Contacts.load();
})
.withFailureHandler(function() {
// TODO: Handle error
})
.createContact(contact);
}
// Server script
function createContact(contactDraft) {
var contact = ContactsApp.createContact(contactDraft.FirsName,
contactDraft.LastName,
contactDraft.Email);
contact.addCompany(contactDraft.Organization, contactDraft.Title);
contact.addPhone(ContactsApp.Field.WORK_PHONE, contactDraft.Phone);
}
Update
Idea to update contact records will be very similar to the new contact creation flow, so I skip it for now.
Delete
Assuming that delete button is located inside contacts table row.
// Client script
function onDeleteContactClick(deleteButton) {
var email = deleteButton.datasource.item.Email;
google.script.run
.withSuccessHandler(function() {
// To update contacts list we can either reload the entire
// datasource or explicitly remove deleted item on the client.
// Second option will work way faster.
var contactIndex = deleteButton.parent.childIndex;
app.datasources.Contacts.items.splice(contactIndex, 1);
})
.withFailureHandler(function() {
// TODO: Handle error
})
.deleteContact(contact);
}
// Server script
function deleteContact(email) {
var contact = ContactsApp.getContact(email);
ContactsApp.deleteContact(contact);
}
Is it possible to select a document at a specific index?
I have a document import process, I get a page of items from my data source (250 items at once) I then import these into DocumentDB in concurrently. Assuming I get an error inserting these items into DocumentDB I wont be sure what individual item or items failed. (I could work it out but don't want to). It would be easier to just Upsert all the items from the page again.
The items i'm inserting have an ascending id. So if i query DocumentDB (ordered by id) and select the id at position (count of all Id's - page size) I can start importing from that point forward again.
I know SKIP is not implemented, I want to check if there is another option?
You could try a bulk import stored procedure. The sproc creation code below is from Azure's github repo. This sproc will report back the number of docs created in the batch and continue trying to create docs in multiple batches if the sproc times out.
Since the sproc is ACID, you will have to retry from the beginning (or the last successful batch) if there are any exceptions thrown.
You could also change the createDocument function to upsertDocument if you just want to retry the entire batch process if any exception is thrown.
{
id: "bulkImportSproc",
body: function bulkImport(docs) {
var collection = getContext().getCollection();
var collectionLink = collection.getSelfLink();
// The count of imported docs, also used as current doc index.
var count = 0;
// Validate input.
if (!docs) throw new Error("The array is undefined or null.");
var docsLength = docs.length;
if (docsLength == 0) {
getContext().getResponse().setBody(0);
return;
}
// Call the CRUD API to create a document.
tryCreate(docs[count], callback);
// Note that there are 2 exit conditions:
// 1) The createDocument request was not accepted.
// In this case the callback will not be called, we just call setBody and we are done.
// 2) The callback was called docs.length times.
// In this case all documents were created and we don't need to call tryCreate anymore. Just call setBody and we are done.
function tryCreate(doc, callback) {
var isAccepted = collection.createDocument(collectionLink, doc, callback);
// If the request was accepted, callback will be called.
// Otherwise report current count back to the client,
// which will call the script again with remaining set of docs.
// This condition will happen when this stored procedure has been running too long
// and is about to get cancelled by the server. This will allow the calling client
// to resume this batch from the point we got to before isAccepted was set to false
if (!isAccepted) getContext().getResponse().setBody(count);
}
// This is called when collection.createDocument is done and the document has been persisted.
function callback(err, doc, options) {
if (err) throw err;
// One more document has been inserted, increment the count.
count++;
if (count >= docsLength) {
// If we have created all documents, we are done. Just set the response.
getContext().getResponse().setBody(count);
} else {
// Create next document.
tryCreate(docs[count], callback);
}
}
}
}
Let's say that two users do changes to the same document while offline, but in different sections of the document. If user 2 goes back online after user 1, will the changes made by user 1 be lost?
In my database, each row contains a JS object, and one property of this object is an array. This array is bound to a series of check-boxes on the interface. What I would like is that if two users do changes to those check-boxes, the latest change is kept for each check-box individually, based on the time the when the change was made, not the time when the syncing occurred. Is GroundDB the appropriate tool to achieve this? Is there any mean to add an event handler in which I can add some logic that would be triggered when syncing occurs, and that would take care of the merging ?
The short answer is "yes" none of the ground db versions have conflict resolution since the logic is custom depending on the behaviour of conflict resolution eg. if you want to automate or involve the user.
The old Ground DB simply relied on Meteor's conflict resolution (latest data to the server wins) I'm guessing you can see some issues with that depending on the order of when which client comes online.
Ground db II doesn't have method resume it's more or less just a way to cache data offline. It's observing on an observable source.
I guess you could create a middleware observer for GDB II - one that checks the local data before doing the update and update the client or/and call the server to update the server data. This way you would have a way to handle conflicts.
I think to remember writing some code that supported "deletedAt"/"updatedAt" for some types of conflict handling, but again a conflict handler should be custom for the most part. (opening the door for reusable conflict handlers might be useful)
Especially knowing when data is removed can be tricky if you don't "soft" delete via something like using a "deletedAt" entity.
The "rc" branch is currently grounddb-caching-2016 version "2.0.0-rc.4",
I was thinking about something like:
(mind it's not tested, written directly in SO)
// Create the grounded collection
foo = new Ground.Collection('test');
// Make it observe a source (it's aware of createdAt/updatedAt and
// removedAt entities)
foo.observeSource(bar.find());
bar.find() returns a cursor with a function observe our middleware should do the same. Let's create a createMiddleWare helper for it:
function createMiddleWare(source, middleware) {
const cursor = (typeof (source||{}).observe === 'function') ? source : source.find();
return {
observe: function(observerHandle) {
const sourceObserverHandle = cursor.observe({
added: doc => {
middleware.added.call(observerHandle, doc);
},
updated: (doc, oldDoc) => {
middleware.updated.call(observerHandle, doc, oldDoc);
},
removed: doc => {
middleware.removed.call(observerHandle, doc);
},
});
// Return stop handle
return sourceObserverHandle;
}
};
}
Usage:
foo = new Ground.Collection('test');
foo.observeSource(createMiddleware(bar.find(), {
added: function(doc) {
// just pass it through
this.added(doc);
},
updated: function(doc, oldDoc) {
const fooDoc = foo.findOne(doc._id);
// Example of a simple conflict handler:
if (fooDoc && doc.updatedAt < fooDoc.updatedAt) {
// Seems like the foo doc is newer? lets update the server...
// (we'll just use the regular bar, since thats the meteor
// collection and foo is the grounded data
bar.update(doc._id, fooDoc);
} else {
// pass through
this.updated(doc, oldDoc);
}
},
removed: function(doc) {
// again just pass through for now
this.removed(doc);
}
}));
Currently my automation framework uses protractor from cucumberJS. We use chai as promised as a assertion library, and I have recently come across a need to do direct mysql queries against a database.
How would I structure a step-definition to be able to get a query, and use the query results within the same step? My current struggles are the asynchronous way protractor is being run, causing me to perform the query after the step requiring the query results happens, and also the scope of which to pass the JSON Object that is created as a result of the query.
this.loginWithMysqlUser = function(uname) {
var mysql = require('mysql');
var connection = mysql.createConnection({
host : 'localhost',
user : '*******',
password : '*******',
database : '*******'
});
connection.connect();
connection.query('SELECT * FROM prot_users WHERE username = ?', [uname], function(err, rows) {
if(err) throw err;
mysqlUser = {
username: rows[0].username,
password: rows[0].password
};
});
connection.end();
loginpage.login(mysqlUser);
};
This function resides on loginpage declaration.
So typically your cucumber test script would like:
Feature: As an admin I would like to check if a customer has an
account
Scenario: Check that customer name is registered in DB
Given that I am logged in as admin
And I wish to check that customer (foo) is registered
Then I expect following details from DB query:
| username | password | database |
| foo | bar | mysql |
with step definitions for:
Given(/^that I am logged in as admin$/, function(callback){
..
logic goes here
..
});
And(/^I wish to check that customer (foo) is registered$/,
function(username, callback){
// create connection with db as described
// with supplied username
// Use a promise to create mySQL connection
// and queries DB based on username as described
// on successful resolution set DBResult to results
// for username, password and database
// on error set DBResult to undefined
});
Then(/^I expect following details from DB query$/, function(data,
callback)
{
var rows = data.raw;
// extract values of input table cells into DBExpect using
// rows[0].username
// rows[0].password
// rows[0].database
// Check equality of DBResult and DBExpect objects
..
expect.isFulfilled(DBResult).toEqual(DBExpect).notify(callback);
});
I ended up containing all of the logic for the login and functions that needed to work with the data within the connection.query function.
Seemed to work ok, and protractor was able to be called from within that query function.
I need to inform clients about changes on server side. In my case I am using different Collections on server and on client (more about it in this question: how would you build pinterest like page with meteor.js).
On the server I am getting new Products from external API. I would like to publish the number of new items to all clients that they could update their local variables needed for layout to work well.
How to do it?
It would be nice if I could publish/subscribe other kinds of data than Meteor.Collection. I found Meteor.deps, but what I understand it works only on client side.
To accomplish what you want you do need another collection - on the client. On the server, in a publish function, build a document from scratch assigning the current count of Products to an attribute. Using observe() and set, modify count when documents are added or removed from Products. Subscribe to the count "record set" on the client.
// Server
Meteor.publish('count', function () {
// Build a document from scratch
var self = this;
var uuid = Meteor.uuid();
var count = Products.find().count();
// Assign initial Products count to document attribute
self.set('count', uuid, {count: count});
// Observe Products for additions and removals
var handle = Products.find().observe({
added: function (doc, idx) {
count++;
self.set('counts', uuid, {count: count});
self.flush();
},
removed: function (doc, idx) {
count--;
self.set('counts', uuid, {count: count});
self.flush();
}
});
self.complete();
self.flush();
self.onStop(function () {
handle.stop();
});
});
// Client
Counts = new Meteor.Collection('count');
Meteor.subscribe('count');
console.log('Count: ' + Counts.findOne().count);
I must say the above solution showed me one way, but still, what if I need to publish to client data that are not connected with observe()? Or with any collection?
In my case I have i.e. 1000 products. To engage visitors I am "refreshig" the collection by updating the timestamp of random number of products, and displaying collection sorted by timestamp. Thank to this visitors have impression that something is happening.
My refresh method returns number of products (it is random). I need to pass that number to all clients. I did it, but using (I think) ugly workaround.
My refresh method sets Session.set('lastRandomNo', random). BTW: I didn't know that Session works on server side. refresh updates Products collection.
Then accoriding to above answer:
Meteor.publish 'refreshedProducts', ->
self = this
uuid = Meteor.uuid()
# create a new collection to pass ProductsMeta data
self.set('products_meta', uuid, { refreshedNo: 0 })
handle = Products.find().observe
changed: (newDocument, atIndex, oldDocument) ->
self.set('products_meta', uuid, { refreshedNo: Session.get('lastRandomNo') })
self.flush()
self.complete()
self.flush()
self.onStop ->
handle.stop()
and on client side:
ProductsMeta = new Meteor.Collection('products_meta')
# subscribe to server 'products_meta' collection that is generated by server
Meteor.subscribe('refreshedProducts')
ProductsMeta.find({}).observe
changed: (newDocument, atIndex, oldDocument) ->
# I have access to refreshedNo by
console.log ProductsMeta.findOne().refreshedNo
What do you think?