Hive-Component
hive-component
is an npm base class that serves as a factory for the hive-mvc
and hive-loader
npm modules.
Usage
Hive Component is a factory to create custom components based on a mixin
and configuration
.
As an example say you want to design a compoennt to add, track and report tags. Tags in this example are lowercased strings,
and you can't have duplicate tags.
A component-using module for tags (`node_modules/tags.js') would be:
var hc = require('./../index');
var config = require('hive-configuration');
var _ = require('underscore');
var util = require('util');
var _DEBUG = true;
var _mixins = {
add_tags: function (tags) {
_.each(tags, _.bind(function (tag) {
this.add_tag(tag);
}, this));
},
add_tag: function (tag) {
if (!tag) {
throw new Error('trying to add nothing')
}
if (!_.isString(tag)) {
throw new Error('attempt to add non-string tag: %s', util.inspect(tag));
}
this._tags.set(tag.toLowerCase(), true);
},
tags: function () {
// @NOTE: not best practice as it depends on internal structure of another module...
return _.sortBy(_.keys(this._tags.data), _.identity);
},
remove_tag: function (tag) {
if (!tag) {
throw new Error('trying to remove nothing')
}
if (!_.isString(tag)) {
throw new Error('attempt to add non-string tag: %s', util.inspect(tag));
}
this._tags.remove(tag);
},
has: function (tag) {
if (!tag) {
throw new Error('trying to test nothing')
}
if (!_.isString(tag)) {
throw new Error('attempt to test non-string tag: %s', util.inspect(tag));
}
return this._tags.has(tag);
}
}
module.exports = function (tags, cb) {
if (!tags) {
tags = [];
}
return hc(_mixins, {
tags: new config(),
init_tasks: [function (cb) {
console.log('init_tasks')
this._tags = new config();
this.add_tags(tags);
cb();
}]
}, cb);
}
Using your custom component would look like this: (a tap
test)
tap.test('tags', function (t) {
Tags(['foo', 'bar'],
function (err, tags) {
tags.init(function () {
t.ok(tags.has('foo'), 'tags has foo');
t.ok(!tags.has('zoo'), 'tags does not have zoo');
t.deepEqual(tags.tags(), ['bar', 'foo'], 'manifest of tags 1')
tags.add_tag('zoo');
t.ok(tags.has('zoo'), 'tags does not have zoo');
t.deepEqual(tags.tags(), ['bar', 'foo', 'zoo'], 'manifest of tags 2');
t.end();
});
}) // end test
});
the Component() function blends the mixins into a new Component object, and sets the configuration of the component.