accessor

accessor

Here's a thing you have to do a lot when using D3 data joins:

// Here, you provide a function to that gets an id from a datum so that D3 
// can correctly identify a corresponding element to update.
var thingElements = rootSelectAll('.leaf').data(
  things, function getId(thing) { return thing.id; }
);
thingElements.enter().append('option');
// Here, you provide a function get gets a label from a datum so that D3 
// can set the text for each element.
thingElements.text(function getLabel(thing) { return thing.label; });
thingElements.exit().remove();

While those accessor functions aren't hard to write, it's easier to just use something that makes them for you, like this:

var thingElements = rootSelectAll('.leaf').data(accessor());
thingElements.enter().append('option');
thingElements.text(accessor('label'));
thingElements.exit().remove();

Installation

npm install accessor

Usage

If you're using Browserify:

var accessor = require('accessor');

Otherwise:

<script src="node_modules/accessor/index.js">

Then, you'll have the accessor function. It takes an argument, property, and returns a function that takes an object and returns that object.property. If you provide no argument property will default to id.

You can specify a second argument, a default value. The accessor will return the default value if the property you're accessing is undefined on the object.

Tests

Run tests with make test.

License

MIT.