CSS Flexbox

• MSDN: https://developer.mozilla.org/en-US/docs/Learn/CSS/CSS_layout/Flexbox
• Tutorial: https://scotch.io/tutorials/a-visual-guide-to-css3-flexbox-properties
• Explained with animated GIFs: https://medium.freecodecamp.com/an-animated-guide-to-flexbox-d280cf6afc35
• Patterns: http://www.flexboxpatterns.com
• Reading the spec: https://hackernoon.com/11-things-i-learned-reading-the-flexbox-spec-5f0c799c776b
• Angular 2 directives: https://github.com/angular/flex-layout
• Flexbox editor: http://flexbox.buildwithreact.com
• Tutorial game: http://flexboxfroggy.com/
• Talk: https://vimeo.com/145055822

JEE CDI annotations in Spring

JSR-330: javax.inject (@Inject). Already supported in Spring.

JSR-299 is only supported in JEE.

JSR-299 annotations recognizing by Spring: https://github.com/matzew/spring-cdi-bridge

CSS resources

• https://css-tricks.com
• Visual guide: http://cssreference.io
• https://medium.com/@codepo8/css-vs-javascript-trust-vs-control-5aa33af978a6

Slippy maps

Projection

• Pseudo-Mercator projection: cilindrial projection of a perfect sphere instead of ellipsoid. 
• http://giscollective.org/slippy-map-projections-explained/
• http://wiki.openstreetmap.org/wiki/Mercator

Tile naming

• Tile naming and maths: https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
• Java/Geotools code: https://github.com/stefan0722/gs-mvt/blob/master/src/main/java/org/geoserver/slippymap/SlippyMapTileCalculator.java
• Python: https://gist.github.com/devdattaT/dd218d1ecdf6100bcf15

Angular 2 UI Toolkits

Angular Material 2
https://github.com/angular/material2
https://github.com/CreativeIT/material-angular-dashboard

PrimeNG
http://www.primefaces.org/primeng

Clarity Design System
https://vmware.github.io/clarity

Semantic UI
https://ng-semantic.herokuapp.com
https://github.com/ozexpert/ng2-semantic-ui

Ng Lightning
http://ng-lightning.github.io

Amexio
https://amexio.tech/

Nebular
https://akveo.github.io/nebular/

JS DataViz libraries

ApexCharts
https://github.com/apexcharts/apexcharts.js
SVG, interactive, responsive

Echarts
https://github.com/ecomfe/echarts
Large datasets, canvas based, glow effects, chinese

Deck.gl
https://uber.github.io/deck.gl
Large datasets, WebGL based

KotoJS
http://kotojs.org/
D3

Chartjs
http://www.chartjs.org
Basic charts, visually light

Dygraphs
http://dygraphs.com/
Canvas
Angular version: https://github.com/mpx200/ng-dygraphs

Taucharts One
https://blog.taucharts.com/taucharts-one/
Grammar similar to D3

Frappe Charts
https://frappe.github.io/charts/

Cahrtist
https://gionkunz.github.io/chartist-js/

Recharts
http://recharts.org/

Flot
http://www.flotcharts.org/
jquery based

Cytoscape.js
http://js.cytoscape.org/
Networks

F2
https://antv.gitbook.io/f2
Mobile

Muze
https://www.charts.com/muze
Data model with algebra

C3.js
https://c3js.org/
D3 v3

Billboard.js
https://github.com/naver/billboard.js
C3 for D3 v4

https://www.codewall.co.uk/the-best-javascript-data-visualization-charting-libraries/

Navigating database relations: Jailer

http://jailer.sourceforge.net/

• DB front end
• Java/Swing
• Navigable FKs

Ngrx

• Official Ngrx example app: https://github.com/ngrx/example-app

• Clear and concise Ngrx tutorial and example that uses Effects to call the backend Service: http://bodiddlie.github.io/ng-2-toh-with-ngrx-suite/

• More about Effects: http://orizens.com/wp/topics/angular-2-ngrxstore-ngrxeffects-intro-to-functional-approach-for-a-chain-of-actions/ 

Angular 2 forms

• Validation: https://angular.io/docs/ts/latest/cookbook/form-validation.html
• Tutorial: http://blog.ng-book.com/the-ultimate-guide-to-forms-in-angular-2/
• Custom form controls: https://blog.thoughtram.io/angular/2016/07/27/custom-form-controls-in-angular-2.html#understanding-controlvalueaccessor
• http://almerosteyn.com/2016/04/linkup-custom-control-to-ngcontrol-ngmodel
• https://toddmotto.com/building-tesla-range-calculator-angular-2-reactive-forms 
• Template vs model driven (& FRP): http://blog.angular-university.io/introduction-to-angular-2-forms-template-driven-vs-model-driven/

Step-by-step building an Angular Material 2 application with Angular CLI

Look no further for up to date but complex Angular 2 seeds and start using Angular CLI.

Angular CLI is now based on Webpack but is simpler.

Versions

• Angular 2.0.0 / 2.0.1
• Material 2.0.0-apha9-3

Project creation

From the command line console (elevated on Windows):

• Upgrade the Node version.
• Install Angular CLI globally: 

npm install -g angular-cli

• Create the project with SCSS support: 

ng new myapp --style=sass

If you are using WebStorm the project creation could also be done with the Angular CLI based.

From here you can always test the application launching it with:

ng serve

Project properties

• Edit package.json and ...
• Set the version.
• Change the license property (or remove it and set private to true).
• Edit index.hmtl and change the title as required.

From CSS to SASS

This is usually automatically done with --style=sass flag on the project creation but reviewing it is suggested.

• Edit angular-cli.json and ...
• Change "styles": ["styles.css"]  to "styles": ["styles.scss"] 
• Change "styleExt": "css" to "styleExt": "scss"
• Rename styles.css to styles.scss
• Rename app.component.css to app.component.scss

Angular 2 version upgrade (Optional)

You can upgrade Angular 2.0.0 to the last stable 2.0.1 version editing package.json and changing the following versions:

"@angular/common": "2.0.1",

"@angular/compiler": "2.0.1",

"@angular/core": "2.0.1",

"@angular/forms": "2.0.1",

"@angular/http": "2.0.1",

"@angular/platform-browser": "2.0.1",

"@angular/platform-browser-dynamic": "2.0.1",

"@angular/router": "3.0.1",    

Material installation

• Install the material module:

npm install --save @angular/material

• Install the HammerJS dependency and its types:

npm install --save hammerjs
npm install --save-dev @types/hammerjs

• Edit app.module.ts and add:

import { MaterialModule } from '@angular/material';

imports: [

  ...

  MaterialModule.forRoot()

]

Material icons linking (Optional)

• Add the Material Icons link on index.html:

<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">

Material theme customization (Optional)

• Add a theme.scss file in the src folder (see https://github.com/jelbourn/material2-app/blob/master/src/material2-app-theme.scss).
• Edit angular-cli.json and change "styles": ["styles.css"] to "styles": ["styles.scss", "theme.scss"] 

Favico setup (Optional)

• Remove favico.ico from src (it's a CLI bug, that's not its location)
• Add your own favico.ico to the assets folder
• Edit index.html and change favico.ico to assets/favico.ico  

Backend proxy setup (Optional)

Useful during development to route certain URL requests to a real server (usually REST calls).

• Add a proxy.conf.json file on the project root folder with the following contents:

{

  "/api": {

    "target": "http://localhost:8080/myapp",

    "secure": false

  }

}

You can start using it with: 

ng serve --proxy-config proxy.conf.json

However it could be simplified by editing the package.json and adding a script:

"scripts": {

  "start": "ng serve --proxy-config proxy.conf.json",

}

So you can now launch it easily with:

npm start

Bundling for production 

You can always generate the production bundles on the dist folder with:

ng build --prod --bh /myapp/

However it could be simplified by edidting the package.json and adding a script:

"scripts": {

    ...

    "build": "ng build --prod --bh /myapp/"

},

So you can now launch it easily with:

npm run build

Internet resources

• https://github.com/angular/angular-cli 
• https://github.com/jelbourn/material2-app/tree/master/src

JPA 2.1

• Named queries at runtime: http://www.thoughts-on-java.org/define-named-queries-runtime-jpa-2-1/

Spring repository in JEE7

• Configure the CDI container to provide a way to access your container managed EntityManager: https://jaxenter.com/top-3-jpa-productivity-boosters-for-java-ee-developers-spring-data-116126.html
• JpaRepositoryFactory: http://simone-folino.blogspot.com.es/2015/04/ejb-with-spring-data-repository.html

Additional WAR on Spring Boot

• Additional WAR: http://stackoverflow.com/questions/31374726/spring-boot-how-to-add-another-war-files-to-the-embedded-tomcat
• JNDI datasource setup: http://stackoverflow.com/questions/31374726/spring-boot-how-to-add-another-war-files-to-the-embedded-tomcat

Other approach:

• JSP in Spring boot executable JAR: http://hillert.blogspot.com.es/2016/03/spring-boot-with-jsp-in-executable-jar.html

Geolatte

http://www.geolatte.org/

• Hibernate based: https://avolpe.github.io/hibernate/2016/06/17/wildfly-10-hibernate-spatial.html
• JTS compatible

Regular expressions

On-line tools

• http://regexr.com
• https://www.debuggex.com
• https://regex101.com

PaaS

"Application infrastructure functionality, enriched with cloud characteristics and offered as a service,

is platform as a service (PaaS). Gartner refers to it more precisely as cloud application infrastructure services."

"Application platform as a service (aPaaS) is a form of PaaS that provides a platform to

support application development, deployment and execution in the cloud."

Pure PaaS players

• Pivotal Cloud Foundry.
• Red Hat OpenShift.
• Aprendaa.
• Heroku.
• Engine Yard.

IaaS hybrid players

• Google?
• Microsoft Azure Cloud Services?
• Amazon AWS
• ...

SaaS hybrids players

• Salesforce
• ...

PaaS frameworks

• Pivotal Cloud Foundry.
• Red Hat OpenShift.
• Apache Stratos.

Related software

• OpenStack
• Docker
• Kubernetes
• Chef

References

•  PaaS and IaaS have really crossed features: http://www.gfi.com/blog/is-paas-the-new-cloud-or-a-passe-term/
• aPaaS Grtner Magic Quadrant 2015: https://www.ibm.com/cloud-computing/files/GARTNER_COMP_magic_quadrant_for_enterpris_271188_Bluemix.pdf

Functional programming

• Why:
• General sateless tendency: cloud & scaling
• No locks (multi-thread)
• Easy reading
• Easy testing
• JavaScript boom?
• How: 
• Pure functions (no side-effects)
• Immutability
• Composition (not inheritance)
• Deferred execution
• Currying
•  ...
• Related: funcional reactive programming.

Why functional programming matters:
https://www.cs.kent.ac.uk/people/staff/dat/miranda/whyfp90.pdf

FP Languages

• Erlang
• Haskell
• OCami
• LISP
• Scheme
• Standard ML
• Wolfram
• Frege (JVM): https://github.com/Frege/frege
• Clojure (JVM)

Hybrid Languages

• Scala (JVM)
• F#

Nginx reverse proxy

proxy_pas without path:

location /some/path/ {

   proxy_pass http://new.domain;
}

http://orig.domain/some/path/x --> http://new.domain/some/path/x

proxy_pas case insensitive:

location ~* /some/path/ {
   proxy_pass http://new.domain;
}

http://orig.domain/SOME/Path/x --> http://new.domain/SOME/Path/x

SSL:

Redirect HTTP to HTTPS: https://bjornjohansen.no/redirect-to-https-with-nginx
Certificate: https://www.digitalocean.com/community/tutorials/how-to-create-a-ssl-certificate-on-nginx-for-centos-6
Optimal (TLS, etc): https://bjornjohansen.no/optimizing-https-nginx

Multiple browser windows applications

Basic Techniques:

• HTML5 postMessage: provides inter-windows message based communication.

• HTML5 local storage: provides a shared storage for all the windows. Windows can be notified of local storage updates through events so this technique can also be used as a postMessage replacement.

• Direct JS: to be tested. ¿limitations?.

childWin = openWindow();

childWin.anyFunction();

Auxiliary techniques

• HTML5 Webworkers.

• Angular app bootstraping tweaks.

Referenes:

• Web-workers / postMessage: https://www.youtube.com/watch?v=-o8B4TE18gI
• Setting the size and position (demo): https://hsablonniere.github.io/window-popup/
• Multiple A2 apps on the same page: https://blog.sstorie.com/bootstrapping-multiple-angular-2-applications-on-the-same-page/
• Sync AngularJS apps through local storage: https://www.undefinednull.com/2014/02/25/angularjs-real-time-model-persistence-using-local-storage/
• Shared authentication through local storage: https://www.guya.net/2015/06/12/sharing-sessionstorage-between-tabs-for-secure-multi-tab-authentication/

Immutables on JavaScript & TypeScript

• JS (most used): https://facebook.github.io/immutable-js/
• JS: https://github.com/rtfeldman/seamless-immutable
• TypeScript lib (decorators): https://github.com/danielearwicker/doop
• TypeScript 2.0 readonly: https://basarat.gitbooks.io/typescript/content/docs/types/readonly.html

OpenLayers 3 resources

https://github.com/webgeodatavore/awesome-openlayers
http://viglino.github.io/ol3-ext/

Spring batch

Configuration

• Java vs XML configuration: https://blog.codecentric.de/en/2013/06/spring-batch-2-2-javaconfig-part-1-a-comparison-to-xml/

Parameters and context

• https://blog.codecentric.de/en/2013/06/spring-batch-2-2-javaconfig-part-2-jobparameters-executioncontext-and-stepscope/

Transactions

• http://docs.spring.io/spring-batch/reference/html/transactions.html
• https://blog.codecentric.de/en/2012/03/transactions-in-spring-batch-part-1-the-basics/
• https://blog.codecentric.de/en/2012/03/transactions-in-spring-batch-part-2-restart-cursor-based-reading-and-listeners/
• https://blog.codecentric.de/en/2012/03/transactions-in-spring-batch-part-3-skip-and-retry/
• http://javabeat.net/transaction-management-in-spring-batch-components/

Scaling

• http://docs.spring.io/spring-batch/reference/html/scalability.html
• https://blog.codecentric.de/en/2013/07/spring-batch-2-2-javaconfig-part-6-partitioning-and-multi-threaded-step/

Examples

• https://github.com/spring-projects/spring-batch/tree/master/spring-batch-samples
• https://thetechnicaljournal.wordpress.com/2016/01/10/spring-boot-batch-starter-example/
• Composite writer example: https://gist.github.com/gnosis23/11258003
• File example: http://www.concretepage.com/spring-batch-3/spring-batch-3-flatfileitemreader-flatfileitemwriter-annotation-example
• RESTful item reader example: https://www.petrikainulainen.net/programming/spring-framework/spring-batch-tutorial-reading-information-from-a-rest-api/

Job database schema

• https://github.com/spring-projects/spring-batch/tree/master/spring-batch-core/src/main/resources/org/springframework/batch/core

Spring boot properties

• http://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html

# Don't create the tables
spring.batch.initializer.enabled=false

# Don't launch all the jobs on app start
spring.batch.job.enabled=fasle

Oracle

• Problem with default transation isalotion level:
• http://stackoverflow.com/questions/22364432/spring-batch-ora-08177-cant-serialize-access-for-this-transaction-when-running
• http://www.eharmony.com/engineering/spring-batch-and-oracle-11g/#.V6cXELh95aQ

Vaadin containers

• BeanItemContainer: the properties of the container are determined automatically by introspecting the used JavaBean class. Uses the beans themselves as identifiers.
• BeanContainer: unlike BeanItemContainer, the item IDs do not have to be the beans themselves.  Uses explicit IDs or implicit IDs with setBeanIdResolver or setBeanIdProperty.

Robocopy

A powerfull copy/delete utility for Windows.

https://technet.microsoft.com/en-us/library/cc733145(v=ws.11).aspx

Usefull on "Source Path Too Long" error:
robocopy d:\path\to\temp\dir node_modules /purge

RxJs resources

http://www.learnrxjs.io/

QueryDSL with SQL

• Complex queries/Spring example: https://github.com/querydsl/querydsl/tree/master/querydsl-examples/querydsl-example-sql-spring
• https://bitbucket.org/atlassian/querydsl-examples

VirtualBox OVA to VSphere OVF

• http://www.itsecurenet.com/virtualbox-ova-to-vsphere-ovf/
• https://felixcentmerino.wordpress.com/2014/10/15/migrate-virtual-machine-from-oracle-virtualbox-to-esxi-5-5/

RapidClipse

https://www.rapidclipse.com/
Eclipse, Hibernate and Vaadin based rapid development environment.

• Complete project setup wizard.
• Good IDE layout: entities, DAOs, UI, etc.
• Nice UI preview.
• Diferent UIs in the same project: desktop, tablet and mobile.
• Database/entity diagram.
• Desktop (SWT) or client-server (HTML) apps.
• Uses Vaadin component subclases (propietary).
• Theme and per component SCSS support.
• Includes authentication and authroization support (DB or LDAP).
• No text documentation available (only screencasts).
• No SQL (no Hibernate) DAO support.
• Maven and Java 8.

Angular 2 change detection

Default behaviour

Change detection is fired on each event loop chance (events, http requets, timers, ...).

Components are allways explored form the root to the leafs of the component tree.

By default, A2 is conservative and explores the complete tree and evaluates all the expressions in each component or directive template. Then compares the output of each expression to its previous output. If the result of an expression has changed, A2 updates the DOM accordingly.

This is as fast as posible; A2 generates change detectors with Javascript VM-friendly code (monomorphic). As the application grows, things may start to lag.

This is the default CD strategy and is called ChangeDetectionStrategy.CheckAllways.

OnPush mode

In order to reduce the performance impact the CD strategy of components can be set to ChangeDetectionStrategy.OnPush.

OnPush means that the change detector will only run on a component or directive if one of the following occurs:

• An input property has changed to a new value (new primitive value or new object reference).
• An event handler fired in the component or directive (???).
• You manually tell the change detector to look for changes.
• The change detector of a child component or directive runs.

OnPush should be implemented starting on leafs, otherwise child components or directives on them with CheckAllways strategy won't be allways executed.

References

• Presentation: http://pascalprecht.github.io/slides/angular-2-change-detection-explained/
• http://victorsavkin.com/post/110170125256/change-detection-in-angular-2
• http://blog.thoughtram.io/angular/2016/02/22/angular-2-change-detection-explained.html
• http://blog.angular-university.io/how-does-angular-2-change-detection-really-work/
• https://www.lucidchart.com/techblog/2016/05/04/angular-2-best-practices-change-detector-performance/
• https://github.com/angular/angular/issues/4746
• Immutable data and ngFor: http://www.jvandemo.com/how-i-optimized-minesweeper-using-angular-2-and-immutable-js-to-make-it-insanely-fast/

STOMP over WebSockets with JSR 356

Atmosphere supports STOMP but subscriptions must be hardcoded on annotations.

Alternative:

• Simple Stampy - JSR 356 (WebSocket) integration
• Stampy: STOMP 1.2 Java implementation

Other Java impl.

• Stilts

JavaScript

• STOMP over WebSockets  (original and discontinued): supports SocksJS and 1.0/1.1 protocol versions
• Webstomp client: (fork of the previous) added 1.2 support. Used on HornetQ broker.

Multiple non modal dialogs in Angular Material

Useful while panel not released (https://material.angularjs.org/HEAD/api/service/$mdPanel)

CSS to prevent modality:

.md-dialog-container {
    pointer-events: none;
}
md-dialog {
    pointer-events: all;
}

Dialog options:

{
/* Don't close this dialog when opening a new one */
    skipHide: true, 
/* Don't do the darkening of the whole screen */
    hasBackdrop: false 

}

References

• http://webiks.com/using-angular-material-dialog-as-a-popup/
• http://webiks.com/mddialog-with-a-confirmation-dialog/

CORS

Under certain request characteristics an additional request is automatically issued by the browser. This "preflight" request gathers CORS information form the server that is checked before making the real request.

References

• Good server CORS implementation (JEE filter) and documentation.

Custom authentication in QlikView Server (NTLM)

It's all about externalizing the user validation.

• Some kind of username mapping (other system --> QlikView) is required.
• Works on any Server edition (Small Business Edition and EE).
• Document access is based on NTFS rights.
• Every user must be given rights for every document. 
• It should be easier and more flexible on Enterprise Edition by activating DMS.
• Also easier with per session licensing (7x more expensive).
• IIS required (it doesn't work with QVS).

Installation

• Install IIS.
• Install QlikView server with IIS-QV Tunneling.
• Set anonymous authentication on the IIS administrator for QlikView and QvAjaxZfc.
• On QMC System -> Setup -> QVW -> Authentication set:
• Authentication: Always
• Type: Ntlm
• Login Address: Default login page
• Edit C:\Program Files\QlikView\Server\QlikViewClients\QlikViewAjax\Authenticathe.aspx

Authenticate.aspx content

<%@ Import Namespace="QlikView.AccessPoint" %>
<%@ Import Namespace="QlikView.AccessPoint.HttpInterfaces" %>
<%@ Import Namespace="QvIISWebServer" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System" %>
<%@ Import Namespace="System.Collections.Generic"%>
<%@ Page Language="C#" AutoEventWireup="true" %>

<script runat="server">
    protected void Page_Load(object sender, EventArgs e) {
        Response.Clear();
        Context context = this.GetContext();
        
        // Saving the Basic authentication header to a string ("Basic UserName:Password")
        string auth = Request.Headers["Authorization"];
        
        bool valid = false;
        string userName = "";            
        if (auth != null && auth.IndexOf("Basic ") == 0)
        {
            // Removing "Basic " from the string and decoding the username and password
            string unameColonPwd = System.Text.Encoding.UTF8.GetString(System.Convert.FromBase64String(auth.Substring(6)));
            int colonPos = unameColonPwd.IndexOf(':');
            if (colonPos >= 0)
            {
                // Splitting username:password into two seperate strings
                userName = unameColonPwd.Substring(0, colonPos);
                string pwd = unameColonPwd.Substring(colonPos + 1);
                
                // *** IMPLEMENT THIS FUNCTION WITH YOUR OWN USER VALIDATION 
                valid = checkCredentials(userName, pwd);
            }
        }            
        
        if(valid)
        {

            // *** IMPLEMENT THIS FUNCTION WITH YOUR OWN USER MAPPING
            userName = "DOMAIN\\" + mapUserName(userName);

            // *** IMPLEMENT THIS FUNCTION TO SET THE USER GROUPS
            // You can also return null on NTFS 
            List<string> groups = getUserGroups(userName);

            // Creating an user object with groups
            IUser user = new NamedUser(userName, groups, true);
            // Associate the IUser with the session cookie and either redirect or sent back a status code
            QlikView.AccessPoint.User.GenericAuthentication(context, user);
            //Stop now so we don't issue a new BASIC challenge                                
            
            /*
            YOU CAN USE THIS HELPER FUNCTION INSTEAD GenericAuthentication WHEN THE NT USER PASSWORD IS KNOWN
            IUser user = QlikView.AccessPoint.User.TryLogon("DOMAIN\\user", "pwd"); 
            */
        }
        else
        {
            Context.Response.StatusCode=401;
            Context.Response.AppendHeader("WWW-Authenticate","Basic realm=\"QlikView\"");
        }

        return;
    }
</script>

Internet references

• IIS installation step-by-step
• Installing IIS 7 with Qlikview 11
• Customized Authentication v2

Browser normalization tools: transpilers, polyfills and shims

Transpiler

• It's a source-to-source compiler.
• Converts and older ES syntax to the new one. 
• Additionally, it's a must when using TypeScript or Coffe-Script to generate the corresponding ES code.
• Executed before deployment, it's a development tool not needed at run-time.

Example: Babel

Polyfills

• A polyfill is code that detects if a certain “expected” API is missing and manually implements it.
• Polyfills often have to use multiple language platforms because sometimes a particular JS API doesn’t exist in that browser at all.
• A JS library and eventually other native artifacts are required at run-time.

Example: core-js

Shim

• A shim is code that intercepts existing API calls and implements different behavior (the API already exists but it must be normalized/patched).
• Usually they are smaller pieces of code than polyfills.
• Usually they are entirely written in JS.
• A JS library it's required at run-time.

Example: es6-shim

References

• Differences between polyfills and shims explanation.
• ES6 tools
• ES7 tools

ES7 async/await

Let you program in a synchronous thinking way.

It's a step forward (after Promises) in the direction of removing the JavaScript "callback hell".

References

• Simplifying asynchronous coding with ES7 async functions
• Taming the async beast with ES7
• ES7 Async/Await
• Async await gotchas

Angular2 I18N: ng2-translate

• GitHub project
• Simplest example
• Advanced seed

Issue with rxjs https://github.com/mgechev/angular2-seed/issues/664

Redux architecture with Angular 2

https://gist.github.com/btroncone/a6e4347326749f938510

http://blog.mgechev.com/2016/04/10/scalable-javascript-single-page-app-angular2-application-architecture/

https://github.com/jhades/angular2-rxjs-single-atom-example

https://github.com/orizens/echoes-ng2/tree/master/src

Building Jasper Reports with code

Two options:

• http://dynamicjasper.com/
• http://www.dynamicreports.org/

The second one is more complete and better documented.

Hystrix

Latency tolerance, fault tolerance and monitoring for distributed systems.
https://github.com/Netflix/Hystrix/wiki

JSON Web Token (JWT)

• JWT for JAX-RS
• JWT auth with Angular JS
• Token Authentication for Java Applications (video)

Other links:

• https://dzone.com/articles/json-web-token-in-action-with-jax-rs
• http://howtodoinjava.com/resteasy/jax-rs-resteasy-basic-authentication-and-authorization-tutorial/
• http://security.stackexchange.com/questions/51294/json-web-tokens-jwt-as-user-identification-and-authentication-tokens
• http://www.developerscrappad.com/1814/java/java-ee/rest-jax-rs/java-ee-7-jax-rs-2-0-simple-rest-api-authentication-authorization-with-custom-http-header/
• http://stackoverflow.com/questions/26777083/best-practice-for-rest-token-based-authentication-with-jax-rs-and-jersey
• http://stackoverflow.com/questions/33663193/implementing-generic-jax-rs-web-service-using-javax-ws-rs-core-application
• http://stackoverflow.com/questions/26777083/best-practice-for-rest-token-based-authentication-with-jax-rs-and-jersey
• http://codingjam.it/json-web-token-jaas-stateless-authentication-per-tomcat/
• https://developer.10duke.com/sdk/api/com/tenduke/sdk2/security/jaas/LoginModuleForJwtAuthentication.html
• http://stackoverflow.com/questions/29766673/custom-jax-rs-authorization-using-jwt-in-each-request

LMAX Disruptor - High performance parallel event processing in Java

Multicast.

Event pre-allocation.

https://github.com/LMAX-Exchange/disruptor

Typical Angular 2 errors

http://stackoverflow.com/questions/35856926/how-to-debug-angular2-in-chrome/35863878

Angular 2 style guides

• https://github.com/johnpapa/angular-styleguide/blob/master/a2/README.md
• https://github.com/mgechev/angular2-style-guide

TypeScript style guides

• Official MS TypeScript Handbook
• Official MS TypeScript Language Specification
• Official MS TypeScript Style Guide
• Another TypeScript Style Guide (Airbnb JS based)

OpenLayers 3

Review

Pros

• Map rotation.
• Large SRS support.
• Reprojection.
• Accurate (pixel-perfect) hit test.
• RTree-indexed features.
• Drawing optimizations (geometry simplification and clipping).
• Wider support of map sources including OGC protocols.
• Styling/symbolizers.
• API compatible WebGL renderer (lines not supported).
• No plugins required: built-in clustering, edition, heatmap and many other features.
• Async rendering with "Beforeoperations”, “postcompose” y “postrender” hooks.

Cons

• Large API.
• Still changing.
• Code size.

Resources

• Official examples
• Hot new features in OpenLayers 3
• Vector use cases
• Advanced styles
• Angular integration

Books

• The book of OpenLayers 3 (online)
• OpenLayers 3 Beginner’s Guide (code)
• Mastering OpenLayers 3

Minimal Angular 2 seed

SystemJS, TypeScript and NPM:
https://github.com/jhades/ng2-minimal

SystemJS, TypeScript, NPM and Gulp:
https://github.com/angular/angular2-seed/tree/systemjs

According to this article it should be a good starting point while angular-cli gets matured.

Java and GeoServer Vector Tiles in MapBox format (MVT)

Spec: https://github.com/mapbox/vector-tile-spec

Java Vector Tiles encoder

https://github.com/ElectronicChartCentre/java-vector-tile

GeoServer Vector Tiles Extension (gs-vectortiles)
https://github.com/geoserver/geoserver/tree/master/src/extension/vectortiles

http://suite.opengeo.org/docs/latest/dataadmin/vectortiles/index.html

GeoServer MVT Extension

https://github.com/stefan0722/gs-mvt

Uses DouglasPeuckerSimplifier.

Interfacing R

OpenCPU - HTTP API for R
https://www.opencpu.org/

• Stateless
• rApache, Nginx, Ubuntu

RApache
http://rapache.net/

RServe - Sockets 
https://rforge.net/Rserve/

R language from Java
https://github.com/jbytecode/rcaller
http://www.rforge.net/JRI/
http://www.renjin.org/
https://bitbucket.org/allr/fastr (http://www.oracle.com/technetwork/java/jvmls2013vitek-2013524.pdf)

Jcmd

https://dzone.com/articles/jcmd-one-jdk-command-line-tool-to-rule-them-all

QlikView extensions

Definition.xml

<ExtensionObject PageHeight="" PageWidth=""/>

• PageWidth: maximum number of columns to retrieve.
• PageHeight: maximum number of  rows to retrieve.

Data Object

• PageSize.x:  current page column count (maximum is PageWidth).
• PageSize.y: current page row count (maximum is PageHeight).
• TotalSize.x: total number of columns on the data set.
• TotalSize.y: total number of rows on the data set.

Selection
You can use the SearchColumn, SelectValuesInColumn or SelectTextsInColumn API methods.

this.Data.SelectTextsInColumn(0, true, value);

You can only make selections in the dimensions that are exposed to the extension.
The extension functions like any chart in QlikView meaning that it can only select in the underlying hypercube

References

• JavaScript API

Vert.x

• Asynchronous programming model.
• Multi-reactor (one ore more event loops).
• Polyglot: Java, JavaScript, Groovy, JRuby, Scala, ...
• Verticles: processing units. Akka/Actor similarities.
• Worker Verticles: blocking code.
• Modules: reusable Verticle set with isolated classloader.
• Local/clustered Shared Map.
• Local/clustered Event Bus.
• HA (auto-deploy of failed Verticles on other nodes).
• Hot deployment (auto-reload on development).
• Light with minimum dependencies: Netty, Jackson & Hazelcast.
• Deployment: fat JAR or minimal Vert.x container.
• Fast: https://www.techempower.com/benchmarks/#section=data-r12&hw=peak&test=json.

Common Crawl

http://commoncrawl.org/

Object to object mapper

• Dozer: the first one and most used. 
• ModelMapper: smart.
• Orika: generates bytecode.
• MapStruct: generates code. Favorite.
• Selma: like MapStruct. Simplest.

Benchmarks:

• http://javaetmoi.com/2015/09/benchmark-frameworks-javas-mapping-objet/
• http://blog.sokolenko.me/2013/05/dozer-vs-orika-vs-manual.html

Comparing two GitHub repos numbers

http://bayne.github.io/github-compare/#!/

CompletableFuture

Basic usage

// Use runAsync instead when the Task is a Runnable
final CompletableFuture<String> f1 = 

    CompletableFuture.supplyAsync(() -> longRunningTask1(params), executor);

final CompletableFuture<String> f2 = ...

final CompletableFuture<String> f3 = ...

// Wait for all to complete

CompletableFuture.allOf(f1, f2, f3).join();

References:

• http://www.nurkiewicz.com/2013/05/java-8-completablefuture-in-action.html
• https://github.com/vandekeiser/parallel-stream-fork-join-pool
• http://www.nurkiewicz.com/2013/05/java-8-definitive-guide-to.html
• https://headcrashing.wordpress.com/2015/07/20/iobound-completablefuture/

Java 8 parallel stream gotchas

When using parallel streams in Java you are using the ForkJoinPool.commonPool() singleton and therefore sharing a single thread pool across the entire program. It, by default, has one less threads as you have processors, as returned by Runtime.availableProcessors() (can be overriden with -Djava.util.concurrent.ForkJoinPool.common.parallelism).

As a consequence:

• You have no control over the pool properties/size.
• There is no isolation between pools so long running tasks or IO locking calls may cause performance problems.

References:

• https://dzone.com/articles/think-twice-using-java-8
• https://dzone.com/articles/whats-wrong-java-8-part-iii

The solution is executing the stream in a specific ForkJoinPool:

ForkJoinPool forkJoinPool = new ForkJoinPool(2);
forkJoinPool.submit(() ->
    IntStream.range(1, 1_000_000)
      .parallel()
      .filter(PrimesPrint::isPrime)
      .collect(toList())
).get();

References:

• https://github.com/vandekeiser/parallel-stream-fork-join-pool
• http://blog.krecan.net/2014/03/18/how-to-specify-thread-pool-for-java-8-parallel-streams/

Other solution using CompletableFuture:

ForkJoinPool forkJoinPool = new ForkJoinPool(2);
CompletableFuture<List<Integer>> primes = CompletableFuture.supplyAsync(() ->
  range(1, 1_000_000)
    .parallel()
    .filter(PrimesPrint::isPrime)
    .collect(toList()), 
  forkJoinPool
);

See next blog entry on  CompletableFuture.