The Holy Java

Notes of a passionate Java EE developer

Posts Tagged ‘JavaScript’

Tools for Editor – Browser Integration for Interactive JS/HTML Development

Posted by Jakub Holý on March 25, 2013

Chrome Development Tools and similar ones are great for interactive, exploratory coding of JavaScript, HTML, and CSS – but the changes aren’t persistent and the tools haven’t the power of a programmer’s editor. I’d like to be able to use a powerful editor yet be able to see changes to JS/HTML/CSS without having to save-[compile]-reload and I want to be able to execute pieces of JS in the context of the browser. Fortunately, there are ways to get at least some of this and it is getting continually better. Let’s see what tools we have now.

These tools usually use either remoting capabilities of the browser or a long-polling connection to the web site, sending and executing JavaScript.

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Posted in Tools | Tagged: , , , | 3 Comments »

Most interesting links of November

Posted by Jakub Holý on November 30, 2011

Recommended Readings

  • Recommended Reading by Poppendiecks – an excellent selection, starting with Lean from Trenches, Management 3.0, Specification by Example, The Lean Startup etc.
  • Eric Allman says that Programming Isn’t Fun Any More  because problem solving has been replaced with learning, configuring, and integrating tons of libraries, frameworks, and tools and many people agree with that (as discussion on reddit proves). In other words we tend to go for any benefit we can have without considering the costs and for “easy” solutions without considering the true enemy: complexity. Perhaps we should always listen to the Rich Hickey’s Simple Made Easy talk before we add a lib/tool/framework?
    • Dean Wampler claims that functional programming can bring the joy back – “[..] a functional language, Scala, Clojure, Haskell, etc. will greatly reduce the amount of code you create. That won’t solve the problem of trying to integrate with too many libraries, but you’ll be less tempted. I also believe those libraries will be less bulky, etc.
    • Few quotes from a related article by M. Taylor: To put it another way, libraries make excellent servants, but terrible masters. | [..] frameworks [..] do keep their promise of making things very quick and easy … so long as you do things in exactly the way the framework author intended | On libraries: [..] we all assume (I know I do) that “plug in solutions X1 and X3″ is going to be trivial. But it never is — it’s a tedious exercise in impedance-matching, requiring lots of time spent grubbing around in poorly-written manuals [..] | On the effect of language choice: [..] different languages, with their different expressive power and especially their different culture, yield very different experiences.
    • To sum it up: Choose your tools and libraries wisely and always mind the global complexity. More usually means worse.
  • Java Magazine – Adam Bien: Stress Testing Java EE 6 Applications (page 41+) – do developer stress testing! Using: JMeter, VisualVM to find out resource consumption and behavior in the application, VisualVM’s Sampler profiling tool [cca 20% overhead], a webapp to extract metrics from GF (STM)
  • Java Magazine – Polyglot Programming on the JVM (page 50; excerpt from The Well-Grounded Java Developer) – why you should consider polyglot programming and how to decide whether to use it and what languages to pick, f.ex.: “These [Java's] qualities make the language a great choice for implementing functionality in the stable layer [of the polyglot programming pyramid]. However, these same attributes become a burden in the middle and upper [lower, DSL, on the linked image] tiers of the pyramid; for example: Recompilation is laborious; Static typing can be inflexible and lead to long refactoring times; Deployment is a heavyweight process; Java’s syntax is not a natural fit for producing DSLs.” “There is a wide range of natural use cases for *alternative languages*. [after identifying such a UC] You *now need to evaluate* whether using an alternative language is appropriate.”
  • Intrusion Detection for Web Apps – Detection Points – If security is a concern of your web application then you should build intrusion detection into the application f.ex. leveraging the  OWASP AppSensor project. The key is to detect malicious/unexpected behavior and proactively do something such as locking the user out or alerting the admins. The page linked above lists some common suspicious behaviors such as the use of multiple usernames, unexpected HTTP command/method, additional/duplicated data in request. Worth checking out!
  • Yammer Moving From Scala to Java- Scala is a cool language but sometimes its cost is higher than the benefits. Snippets from the post: “…the friction and complexity that
    comes with using Scala instead of Java isn’t offset by enough productivity benefit or reduction of maintenance burden …”. “Scala, as a language, has some profoundly interesting ideas in it. [...] But it’s also a very complex language. The number of concepts I had to explain to new members of our team for even the simplest usage of a collection was surprising: implicit parameters, builder typeclasses, ‘operator overloading’, return type inference, etc. etc.” (It’s claimed that only library authors need to know some of that but if it’s a part of library APIs, the users need to understand it too.) Notice that the author isn’t saying “Scala is bad” but only that Scala isn’t the best balance of their needs at this time, as Alex Miller put it*.
    Important note
    : The text wasn’t intended for publication and it is a private opinion of a Yammer developer, not the company itself. You should read the official Yammer’s position where Coda puts it into the right context.

Refactoring

  • Opportunistic Refactoring by Martin Fowler – refactor on the go – how & why
  • Michael Feathers: Getting Empirical about Refactoring – gather information that helps us understand the impact of our refactoring decisions using data from a SCM, namely File Churn (frequency of changes, i.e. commits) vs. Complexity – files with both high really need refactoring. Summary: “If we refactor as we make changes to our code, we end up working in progressively better code. Sometimes, however, it’s nice to take a high-level view of a code base so that we can discover where the dragons are. I’ve been finding that this churn-vs.-complexity view helps me find good refactoring candidates and also gives me a good snapshot view of the design, commit, and refactoring styles of a team.

UIs and Web Frameworks

  • Devoxx 2011 - WWW: World Wide Wait? A Performance Comparison of Java Web Frameworks (slides) – the authors did extensive performance testing of some of the most popular web frameworks. Of course it’s always hard to guess how general their results are, if/how they apply to one’s particular situation, and if they aren’t distorted in some way but it’s worth for their approach alone (AWS with its CloudWatch monitoring, WebDriver, additional measurement of page load with HAR and a browser plugin). In their particular tests GWT scored best, followed by Spring MVC, with JSF and Wicket lagging far behind (especially the MyFaces implementation). Conclusion: A web framework may have strong impact on performance and scalability, if they are important for you then do test the performance early with as realistic code and load as possible.
  • JSF2 – Benchmark datatable by N. Labrot, 2/2011 – performance comparison of PrimeFaces 2.2.1, IceFaces 2.0, Richfaces 4.0.0M4 on a simple page with Ajax. I do not trust any benchmark that I don’t fake myself :-) (for there are always too many factors that influence the conclusions to be drawn) but it’s interesting anyway – and perhaps a good thing to do before you decide for a JSF component library.
  • Alex MacCaw: Asynchronous UIs – the future of web user interfaces and the Spine framework – users in 2011 shouldn’t anymore wait for pages to load and operations to complete, we should build asynchronous UIs where changes to the UI are performed immediately while a request to the server is sent in the background, similarly to sending e-mail in GMail, which returns at once displaying a non-intrusive “Sending…” notification. As a user I very much agree with Alex.
  • Matt Raible’s 20 criteria for evaluating web frameworks, 2010 (detailed description, here’s a brief list) – Matt’s results are disputable and as he himself says you should always do your own evaluation and spikes but the criteria are pretty useful: Developer Productivity, Developer Perception, Learning Curve, Project Health, Developer Availability, Job Trends, Templating, Components, Ajax, Plugins or Add-Ons, Scalability, Testing, i18n and l10n, Validation, Multi-language Support (Groovy / Scala), Quality of Documentation/Tutorials, Books Published, REST Support (client and server), Mobile / iPhone Support, Degree of Risk.

NoSql

  • Don’t use MongoDB via @nicolaiarocci – a (fake?!) bad experience with MongoDB – the text is not credible (the author is anonymous, s/he doesn’t explicitely state which version of MongoDB they used, the 10gen CTO can’t find a matching client and any evidence for some of the issues mentioned) but it  gives context for the read-worthy response from the 10gen CTO, and a post that nicely explains how to correctly design for MongoDB. A comment about MongoDB experience at Forsquare: “Currently we have dozens of MongoDB instances across several different data clusters storing over a TB of data and handling 10s of thousands of requests per second (mostly reads but the write load is reasonably high as well).Have we run into problems with MongoDB along the way? Yes, of course we have. It is a new technology and problems happen.Have they been problematic enough to seriously threaten our data? No they have not.
  • Martin Fowler on Polyglot Persistence – the are when will be choosing persistence solution with respect to our needs instead of mindlessly picking RDBMS is coming. Applications will combine multiple, specific solutions, f.ex. we could pick Redis (key-value) for caching, MongoDB (document DB) for product catalog, Neo4J (graph DB) for recommendations, RDBMS for financial data and reporting… (of course not all in one project!). Polyglot persistence will come at a cost (complexity, learning) – but it will come because the benefits are worth it – performance, data storage model and behavior more aligned with the business logic (NoSql databases ofer various models and tradeoffs and thus we can find a much better fit than with general-purpose RDBMs).

Talks & Video

  • Adam Bien’s JavaOne talk Java EE 6: The Cool Parts (1h) – absolutely worth the time – a very practical fly through the cool features of Java EE (eventing, ..), most of the time is spent actually coding. Don’t forget to check also the interesting discussion below the video (JEE and other frameworks, Java FX and JSF 2, …).
  • Jurgen Appelo’s keynote How to Change the World at Smidig 2011 is well done and highly useful. We all strive to change the world around us – as consultants we want to make our clients more agile, as team members we want to make our Scrum teams more self-organizing, as employees we want to help building knowledge-sharing and open culture, … . However it isn’t easy to influence or change people and culture and if we aren’t aware of all the dimensions of a change (system, individuals, interactions, environment) and how to work along each of them, we are much less likely to succeed. The knowledge and experience that Jurgen shares with us can help us a lot in having an impact. You can also download the slides and change management questions.
  • Project X: What is being a programmer like? (5min) If ever again a non-geek asks you what you as a developer are doing, just show him this short and extremely funny video (created by my ex-employer – perhaps they estimated how much time and energy developers loose trying to explain it to normal people and decided to prevent this great waste :-) )
  • RSA Animate – Drive: The surprising truth about what motivates us (10 min) – entertaining and enlightening; once we’ve enough money to cover our needs, it’s autonomy (self-direction), mastery, and purpose what motivates us (money actually decrease our performance). Now this is a great evidence for lean/agile – for they’re based on making people self-directing and encourage mastery (as in continous integration and top quality to enable steady pace). Autonomy enables engagement as does a higher purpose (“make the world a better place”) – Steve Jobs with his visions was able to provide such a purpose. Atlassian’s FedEx Days are a good example of what engagement and benefits autonomy brings.
  • Simon Sinek: How great leaders inspire action (18 min, subtitles in 37 languages) – do you want to succeed, to change the world around you for the better, to start a new company? Then you must start by communicating “why” you do what you do, not “what” – like M. L. King, bro Wrights, and Apple. Very inspiring! (More in his Why book.)

Links to Keep

Favorite Quotes

Refactoring is like advertising: it doesn’t cost, it pays.
- Mary & Tom Poppendiecks, Implementing Lean Software Development, p.166

Clojure Corner

Posted in Databases/DB2, General, j2ee, Top links of month | Tagged: , , , , , , , , , , , | Leave a Comment »

Most interesting links of October

Posted by Jakub Holý on October 31, 2011

Recommended Readings

  • Steve Yegge’s Execution in the Kingdom of Nouns – I guess you’ve already read this one but if not – it is a well-written and amusing post about why not having functions as first class citizens in Java causes developers to suffer. Highly recommended.
  • Reply to Comparing Java Web Frameworks – a very nice and objective response to a recent blog summarizing a JavaOne presentation about the “top 4″ web frameworks. The author argues that based on number of resources such as job trends, StackOverflow questions etc. (however data from each of them on its own is biased in a way) JSF is a very popular framework – and rightly so for even though JSF 1 sucked, JSF 2 is really good (and still improving). Interesting links too (such as What’s new in JSF 2.2?). Corresponds to my belief that GWT and JSF are some of the best frameworks available.
  • Using @Nullable – use javax.annotation.Nullable with Guava’s checkNotNull to fail fast when an unexpected null appeares in method arguments
  • JavaOne 2011: Migrating Spring Applications to Java EE 6 (slides) – nice (and visually attractive) comparison of JavaEE and Spring and proposal of a migration path. It’s fun and worthy to see.
  • xUnitPatterns – one of the elementary sources that anybody interested in testing should read through. Not only it explains all the basic concepts (mocks, stubs, fakes,…) but also many pitfalls to avoid (various test smells such as fragile tests due to Data Sensitivity, Behavior Sensitivity, Overspecified Software [due to mocks] etc.), various strategies (such as for fixture setup), and general testing principles. The materials on the site were turned into the book xUnit Test Patterns: Refactoring Test Code (2007), which is more up-to-date and thus a better source.
  • Eclipse tip: Automatically insert at correct position: Semicolon, Braces – in “while(|)” type “true {” to get ”while(true) {|” i.e. the ‘{‘ is moved to the end where it belongs, the same works for ‘;’
  • Google Test Analytics – Now in Open Source – introduces Google’s Attributes-Components-Capabilities (ACC) application intended to replace laborous and write&forget test plans with something much more usable and quicker to set up, it’s both a methodology for determining what needs to be tested and a tool for doing so and tracking the progress and high-risk areas (based not just on estimates but also actual data such as test coverage and bug count). The article is a good and brief introduction, you may also want to check a live hosted version and a little more detailed explanation on the project’s wiki.
  • JSF and Facelets: build-time vs. render-time (component) tags (2007) – avoid mixing them incorrectly
  • StackOverflow: What are the main disadvantages of Java Server Faces 2.0? Answer: The negative image of JSF comes from 1.x, JSF 2 is very good (and 2.2 is expected to be just perfect :-) ). Nice summary and JSF history review.
  • Ola Bini: JavaScript in the small – best practices for projects using partly JavaScript – the module pattern (code in the body of an immediately executed function not to polute the global var namespace), handling module dependencies with st. like RequireJS, keeping JS out of HTML, functions generating functions for more readable code, use of many anonymous functions e.g. as a kind of named parameters, testing, open questions.

Talks

  • Kent Beck’s JavaZone talk Software G Forces: The Effects of Acceleration is absolutely worth the 1h time. Kent describes how the development process, practices and partly the whole organization have to change as you go from annual to monthly to weekly, daily, hourly deployments. What is a best practice for one of these speeds becomes an impediment for another one – so know where you are. You can get an older version of the slides and there is also a detailed summary of the talk from another event.
  • Rich Hickey: Simple Made Easy - Rich, the author of Clojure, argues very well that we should primarily care for our tools, constructs and artifacts to be “simple”, i.e. with minimal complexity, rather than “easy” i.e. not far from our current understanding and skill set. Simple means minimal interleaving – one concept, one task, one role, minimal mixing of who, what, how, when, where, why. While easy tools may make us start faster, only simplicity will make it possible to keep going fast because (growing) comlexity is the main cause of slowness.  And simplicity is a choice – we can create the same programs we do today with the tools of complexity with drastically simpler tools. Rich of course explains what, according to him, are complex tools and their simple(r) alternatives – see below. The start of the 1h talk is little slow but it is worth the time. I agree with him that we should much more thing about the simplicity/complexity of the things we use and create rather than easiness (think ORM).
    Read also Uncle Bob’s affirmative reaction (“All too often we do what’s easy, at the expense of what’s simple. And so we make a mess. [...] doing what is simple as opposed to what is easy is one of the defining characteristics of a software craftsman.”).

Random Notes from Rich’s Simple Made Easy Talk:

There are also better notes by Alex Baranosky and you may want to check a follow-up discussion with some Rich’s answers.

The complex vs. simple toolkit (around 0:31):

COMPLEXITY                             SIMPLICITY
State, objects                            Values
Methods                                   Functions, namespaces
vars                                          Managed refs
Inheritance, switch, matching  Polymorphism a la carte
Syntax                                      Data
Imperative loops, fold              Set functions
Actors                                      Queues
ORM                                         Declarative data manipulation
Conditionals                             Rules
Inconsistency                            Consistency

What each of the complexity constructs mixes (complects) together

CONSTRUCT                        COMPLECTS (MIXES)
State, objects – everything that touches it (for state complects time and value)
Methods – function and state, namespaces (2 classes, same m. name)
Syntax – Meaning, order
Inheritance – Types (ancestors, child)
Switch/matching – Multiple who/what pairs (1.decide who, 2.do what ?)
var(iable)s – Value, time
Imperative loops, fold – what/how (fold – order)
Actors – what/who
ORM – OMG :-)
Conditionals – Why, rest of program (rules what program does are intertw. with the structure and order of the program, distributed all over it)

HE SIMPLICITY TOOLKIT (around 0:44)
CONSTRUCT            GET IT IVA…
Values – Final, persistent collections
Functions – a.k.a. stateless methods
Namespaces – Language support
Data – Maps, arrays, sets, XML, JSON etc.
Polymorphism a la carte – Protocols, Haskell type classes
Managed refs – Clojure/Haskell refs (compose time and value , not mix)
Set functions – Libraries
Queues – Libraries
Declarative data manipulation – SQL/LINQ/Datalog
Rules – Libraries, Prolog
Consistency – Transactions, values

True abstraction isn’t hiding complexity but drawing things away – along one of the dimensions of who, what, when, where, why [policy&rules of the app.], how.
Abstraction => there are things I don’t need – and don’t want – to know.
Why – do explore rules and declarative logic systems.
When, where – when obj. A communicates with obj. B. => put a queue in between them so that A doesn’t need to know where B is; you should use Qs extensively.

Links to Keep

  • Incredibly Useful CSS Snippets -  “a list of CSS snippets that will help you minimize headaches, frustration and save your time while writing css” – few float resets, targetting specific browsers & browser hacks, cross-rowser transparency/min height/drop shadow, Google Font API, link styled by file type,

DevOps: Tools and libraries for system monitoring and (time series) data plotting

  • Hyperic SIGAR API – open-source library that unifies collection of system-related metrics such as memory, CPU load, processes, file system metrics across most common operating systems
  • rrd4j – Java clone of the famous RRDTool, which stores, aggregates and plots time-series data (RRD = round-robin database, i.e. keeps only a given number of samples and thus has a fixed size)
  • JRDS “is performance collector, much like cacti or munins”, uses rrd4j. The documentation could be better and it seems to be just a one man project but it might be interesting to look at it.

Clojure Corner

  • Alex Miller: Real world Clojure – a summary of experiences with using Clojure in enterprise data integration and analytics products at Revelytix, since early 2011 with a team of 5-10 devs. Some observations: Clojure code is 1-2 order of magnitude smaller than Java. It might take more time to learn than Java but not much. Clojure tooling is acceptable, Emacs is still the best. Debugging tools are unsurprisingly quite inferior to those for Java. Java profiling tools work but it may be hard to interpret the results. “[..]  I’ve come to appreciate the data-centric approach to building software.” Performance has been generally good so far.
  • Article series Real World Clojure at World Singles – the series focuses on various aspects of using Clojure and how it was used to solve particular problems at a large dating site that starting to migrate to it in 2010. Very interesting. F. ex. XML generation, multi-environment configuration, tooling (“If Eclipse is your drug of choice, CCW [Counter ClockWise] will be a good way to work with Clojure.”, “Clojure tooling is still pretty young [..]  - but given how much simpler Clojure is than most languages, you may not miss various features as much as you might expect!”)
  • StackOverflow: Comparing Clojure books – Programming Clojure, Clojure in Action, The Joy of Clojure, Practical Clojure – which one to pick? A pretty good comparison.
  • Clojure is a Get Stuff Done Language – experience report – “For all that people think of Clojure as a “hard” “propeller-head” language, it’s actually designed right from the start not for intellectual purity, but developer productivity.”

Posted in eclipse, General, j2ee, Java, Testing, Top links of month | Tagged: , , , , , , , , , | 3 Comments »

Most interesting links of May

Posted by Jakub Holý on May 31, 2011

Recommanded Readings

Acceptance testing / Specification by example:

  • Gojko Adzic: Anatomy of a good acceptance test - an example of refactoring a bad acceptance test into a good one – good for learning about pitfalls and how a good one should look like
  • Gojko: Top 10 reasons why teams fail with Acceptance Testing – acceptance testing is great and brings lot of value but must not be underestimated; some of the problems are bad collaboration, focusing on “how” instead of “what,” confusing AT with full regression tests. Brief, worth reading.
  • Specification by Example: a love story (go directly to the PDF with the story): A nice, made-up story of going from low-level, workflow-based Selenium tests through similar Cucumber ones to true BDD tests describidng clearly what, not how – very well shows the point of specification by example and how it should (and should not) look like

(Enterprise) Java best practices:

  •  Clean code, clean logs: 10 brief posts on logging best-practices – nothing really new here for me but in total it is a very good overview that every developer should know
  • Make Large Scale Changes Incrementally with Branch By Abstraction – Continuous integration doesn’t work well with branches but as this article shows, you can manage even large-scale refactorings without branches using “branch by abstraction,” an approach reminding me of Fowler’s “strangler application” (an incremental replacement of a legacy system). The idea is: 1. Create an abstraction over the part of code to be changed;  2. Refactor the code to use it; 3. Implement new functionality using the new way / step by step move old functionality too, the abstraction layer delegating either to the new or old implementation … . It may be more work but: 1) your software is always working and deliverable; 2) (side-effect) in the end it will be more decoupled

Git:

  • John Wiegley’s Git from the bottom upp (31p, Git 1.5.4.5, PDF) – a useful explanation of the fundamentals of Git, i.e. how it is constructed and how it works, which makes it much easier to understand how to  use it properly (recommended by Pål R.). Reading the The Git Parable first may be a good idea for an easy introduction into the fundamentals, though absolutely not necessary. This document introduces very well the important Git concepts (blob, index, commit, commit names such as branches, reflog) and how they cooperate to provide the rich set of functionality it has. It also explains well the value and usage of rebase. Among others I’ve appreciated the tip to use checkout, branch -m <new-branch> master, branch -D instead of the much more dangerous reset –hard and the tip to use stash / stash apply to create daily backups of your working tree in the reflog (with clearing it with ‘git reflog expire –expire=30.days refs/stash‘ instead of stash clear). Also git diff/log master..[HEAD] for reviewing work done in the current branch and and git diff/log ..master for checking the changes since the last merge/rebase after a fetch are interesting.

Tools:

  • The secret power of bookmarklets - bookmarklets are an indispensable tool for every developer who works with web applications (to fill in test data, speed up log in, …), yet I’m sometimes surprised by meeting people who don’t know or use them; this blog explains them nicely, links to some useful ones and some useful tools for building them

Recommended Books

  • (*****) Implementing Lean Software Development: From Concept to Cash by Mary Poppendieck, Tom Poppendieck – A great introduction into lean thinking (the values and principles it is build upon), clearly communicated with the help of “war stories”. I absolutely recommend it to anybody interested in lean/agile.
  • (**** ) Agile Project Management with Scrum (Microsoft Professional) by Ken Schwaber – Even though you can’t understand Scrum without experiencing it, this book full of war stories will help you to avoid many Scrum implementation pitfalls and to understand its mantra of “the art of the possible” and will show you how to adapt Scrum to various situations. It’s very easy to read thanks to its format of brief case studies organized by topics (team, product owner, …).

Favourite Quotes of the Month

@unclebobmartin: Cleaning code does NOT take time. NOT cleaning code does take time.

Posted in General, Java, Testing, Tools, Top links of month | Tagged: , , , , , , , , , | Leave a Comment »

CKEditor: Collapsing only 2nd+ toolbar rows – howto

Posted by Jakub Holý on April 1, 2011

Normally CKEditor (v3.5.2) hides/shows all the toolbar buttons when you press the collapse/expand button but I needed to always show the first row with “basic tools” and only collapse the second and following rows with advanced functionality tool buttons. CKEditor doesn’t have proper support for that but there is a simple workaround.

Update: Example solution (CKEditor 3.6.1) published, see the changes done or download the full source and open _samples/replacebyclass.html.

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Posted in General | Tagged: , , | 5 Comments »

Most interesting links of October

Posted by Jakub Holý on October 31, 2010

Few of my favourite themes this month – TDD, performance, build tools/Maven. Plus a usefel JS library, news from the Java community x Oracle world etc.

  • About dying JCP and too silent Oracle (or mostly silent) – a summary of the latest issues and hot topics in the Java community that cause lot of rumor but still no reaction from Oracle including the criticism of JCP and its proclaimed decline. Update 11/1: The article about IBM, Oracle and OpenJDK has links to many related resources and a section on JCP future.
  • A fair evaluation of TDD – Test driven development at Transloadit (“honest assessment of the beauty and pain of tdd” – Kent Beck) – according to the author, TDD requires a lot of discipline and is a pain to do but it really pays off if your risks are high, basically it’s something like an insurance – there are people living without it but to some it can save life. I miss there a thing I find essential about good test coverage – namely that it forces you to write a better code (more modular, following the single responsibility principle etc.).
  • Dear Javascript Guru: Please Stop Using The Hash Symbol For No-Op HREFs – don’t use href=”#” for it modifies the browsing history and makes the browser scroll to the top. Prefer <a href=”javascript:void(0);” … > or just use the javascript: protocol for a function call that returns false (you can force it like this: <a href=”javascript:doSomething(); void(0);”>).
  • Why Hibernate 4 switches to Gradle instead of Maven 3 – “a means to describe the issues and frustrations I have seen in my 2.5+ years of using Maven for Hibernate builds; in many cases the cause is simply an assumption or concept in Maven itself which did not line up cleanly with how I wanted to do build stuff in Hibernate.” The main issues were that Hibernate is a very specific project, which doesn’t line up very well with the Maven philosophy and, at the same time, Maven is very strict at forcing it and not really flexible to accommodate to unusual needs (and if Maven is, its plugin often aren’t). For example Hibernate is composed of modules that depend on each other while Maven really supports only an aggregation of independent projects. Also, “the release plugin is completely worthless”. On the other hand, Gradle is very flexible and – among others – offers powerful scripting, doesn’t enforce its way of doing things at all cost (i.e. directory structure), let you also define dependencies on tasks, modules, directories, etc.
  • Flot – JavaScript plotting library for jQuery, which has replaced Flash at WordPress.com (so it must be really good!) for blog statistics visualization. Main points: simple usage (all settings are optional), attractive looks and interactive features like zooming and mouse tracking. Really nice one! Check Flot examples.
  • String Concatenation Performance vs. String Builder/Buffer and how Liferay 6 achieved a speedup by not using S.B. [that much] – StringBuilder/Buffer has lot of overhead and thus String.concat or custom code can be faster sometimes. Also see the linked ticket, esp. the comment ‘most javac will try to translate “+” to StringBuilder whenever possible. So if you do need to use String.concate(), you’d better use it explicitly.’
  • Paul Graham – Beating the Averages – why it’s good to learn Lisp. (Because it makes you able to see the limitations of you current language as it’s most likely superior to it – among others thanks to Lisp macros.) A really good essay on the power of programming languages, which has persuaded me about some year ago, when I’ve originally read it, to learn Clojure (a modern Lisp dialect running on the JVM).

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