Monthly Archives: October 2013

Metaprogramming experiments: Selector Properties

Hello everyone!

A few days ago I wrote a post about “Virtual Instances in JavaScript with Proxy API โ€“ JSDataViews“.
It’s an approach on how to calculate the data representation of a variable at runtime with the help of the new Proxy API.

Today I want to show another feature which is part of the core of JSDataViews

Selector Properties

A lot of people are familiar with jQuery. The development of jQuery is driven by the fact that the DOM is a hierarchical, complex data structure and people need an easy way to access and manipulate different parts of it.
Since JavaScript objects can reach a similar complexity I was looking for an easy and nice way to run similar queries on them.
Continue reading Metaprogramming experiments: Selector Properties

How to install Couchbase for Node.js on a Windows 8 machine


Update: You’re reading the Couchbase Post of the Week!
pow


Working Installation

This should be a working step-by-step installation. If you’re interested in a particular error or how I got to this steps please read the article below.

1. Make sure you have python >=2.5 and < 3.0 (eg 2.7) installed 2. Download and install libcouchbase (search for windows)
2b. Ensure that your folder structure matches the
binding.gyp – (try to access C:\couchbase\bin\libcouchbase.dll in your explorer)
3. Download and install a C/C++ compiler (e.g. via Visual Studio Express for Win8)
4. Set path to python in your shell like so: set PYTHON=C:\Dev\Python27\python.exe
6. Run

(7.) If the gyp config does not match your visual studio edition use flags:

Tips for Mac Users

For additional information please refer to the node-gyp requirements page

Test it

Tugdual Grall has a simple test example on his page which unfortunately seems to be outdated. Here is a newer one:

I hope this helps some people out there ๐Ÿ˜‰

Continue reading How to install Couchbase for Node.js on a Windows 8 machine

Virtual Instances in JavaScript with Proxy API – JSDataViews

Today I discovered an interesting new way of declaring variables. I used a technique to mimic a principle which is called “Views” and which is well known in the database world.

DB Views !== UI Views

On the PostgreSQL website Views are described as follows:

The view is not physically materialized. Instead, the query is run every time the view is referenced in a query.

The principle can be simply visualized using a set of data entries where each “View” builds a subset of these entries (colored boxes) when executed:

db views

Enter JS

Instead of declaring the final variable/dataset for the View we will create a function that behaves like a View object. I’ll call this a Virtual Instance since the data for this View is not existent before it is accessed. Instead, the function is evaluated and brings data into the ย variable at runtime.
Continue reading Virtual Instances in JavaScript with Proxy API – JSDataViews