added base code...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
This commit is contained in:
Alex A. Naanou 2016-08-20 23:46:34 +03:00
parent 90d8f0db1b
commit ab4e2275ce
3 changed files with 2107 additions and 2 deletions

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actions.js Executable file

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features.js Executable file
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/**********************************************************************
*
*
*
**********************************************************************/
(typeof(define)[0]=='u'?function(f){module.exports=f(require)}:define)(
function(require){ var module={} // makes module AMD/node compatible...
/*********************************************************************/
var args2array = require('lib/util').args2array
var actions = require('lib/actions')
var object = require('lib/object')
/*********************************************************************/
//
// Feature attributes:
// .tag - feature tag (string)
// this is used to identify the feature, its event handlers
// and DOM elements.
//
// .title - feature name (string | null)
// .doc - feature description (string | null)
//
// .priority - feature priority
// can be:
// - 'high' (99) | 'medium' (0) | 'low' (-99)
// - number
// - null (0, default)
// features with higher priority will be setup first,
// features with the same priority will be run in order of
// occurrence.
// .suggested - list of optional suggested features, these are not
// required but setup if available.
// This is useful for defining meta features but without
// making each sub-feature a strict dependency.
// .depends - feature dependencies -- tags of features that must setup
// before the feature (list | null)
// .exclusive - feature exclusivity tags (list | null)
// an exclusivity group enforces that only one feature in
// it will be run, i.e. the first / highest priority.
//
// .actions - action object containing feature actions (ActionSet | null)
// this will be mixed into the base object on .setup()
// and mixed out on .remove()
// .config - feature configuration, will be merged with base
// object's .config
// NOTE: the final .config is an empty object with
// .__proto__ set to the merged configuration
// data...
// .handlers - feature event handlers (list | null)
//
//
//
// .handlers format:
// [
// [ <event-spec>, <handler-function> ],
// ...
// ]
//
// NOTE: both <event-spec> and <handler-function> must be compatible with
// Action.on(..)
//
//
// Feature applicability:
// If feature.isApplicable(..) returns false then the feature will not be
// considered on setup...
//
//
// XXX this could install the handlers in two locations:
// - mixin if available...
// - base object (currently implemented)
// should the first be done?
var FeatureProto =
module.FeatureProto = {
tag: null,
isApplicable: function(actions){
return true
},
getPriority: function(){
var res = this.priority || 0
return res == 'high' ? 99
: res == 'low' ? -99
: res == 'medium' ? 0
: res
},
setup: function(actions){
var that = this
// mixin actions...
if(this.actions != null){
actions.mixin(this.actions)
}
// install handlers...
if(this.handlers != null){
this.handlers.forEach(function(h){
actions.on(h[0], that.tag, h[1])
})
}
// merge config...
// NOTE: this will merge the actual config in .config.__proto__
// keeping the .config clean for the user to lay with...
if(this.config != null
|| (this.actions != null
&& this.actions.config != null)){
var config = this.config = this.config || this.actions.config
if(actions.config == null){
actions.config = Object.create({})
}
Object.keys(config).forEach(function(n){
// NOTE: this will overwrite existing values...
actions.config.__proto__[n] = config[n]
})
}
// custom setup...
// XXX is this the correct way???
if(this.hasOwnProperty('setup') && this.setup !== FeatureProto.setup){
this.setup(actions)
}
return this
},
remove: function(actions){
if(this.actions != null){
actions.mixout(this.actions)
}
if(this.handlers != null){
actions.off('*', this.tag)
}
if(this.hasOwnProperty('remove') && this.setup !== FeatureProto.remove){
this.remove(actions)
}
// remove feature DOM elements...
actions.ribbons.viewer.find('.' + this.tag).remove()
return this
},
}
// XXX is hard-coded default feature-set a good way to go???
//
// Feature(obj)
// -> feature
//
// Feature(feature-set, obj)
// -> feature
//
// Feature(tag, obj)
// -> feature
//
//
// Feature(tag, actions)
// -> feature
//
// Feature(feature-set, tag, actions)
// -> feature
//
var Feature =
module.Feature =
function Feature(feature_set, tag, obj){
if(arguments.length == 2){
// Feature(<tag>, <obj>)
if(typeof(feature_set) == typeof('str')){
obj = tag
tag = feature_set
feature_set = Features
// Feature(<feature-set>, <obj>)
} else {
obj = tag
tag = null
}
// Feature(<obj>)
} else if(arguments.length == 1){
obj = feature_set
feature_set = Features
}
if(tag != null && obj.tag != null && obj.tag != tag){
throw 'Error: tag and obj.tag mismatch, either use one or both must match.'
}
// action...
if(obj instanceof actions.Action){
if(tag == null){
throw 'Error: need a tag to make a feature out of an action'
}
var f = {
tag: tag,
actions: obj,
}
obj = f
// meta-feature...
} else if(obj.constructor === Array){
if(tag == null){
throw 'Error: need a tag to make a meta-feature'
}
var f = {
tag: tag,
suggested: obj,
}
obj = f
// feature...
} else {
obj.__proto__ = FeatureProto
}
if(feature_set){
feature_set[obj.tag] = obj
}
return obj
}
Feature.prototype = FeatureProto
Feature.prototype.constructor = Feature
var FeatureSetProto = {
__feature__: Feature,
__actions__: actions.Actions,
// if true, .setup(..) will report things it's doing...
__verbose__: null,
// List of registered features...
get features(){
var that = this
return Object.keys(this)
.filter(function(e){
return e != 'features'
&& that[e] instanceof Feature })
},
// Build list of features...
//
// Build list of all features for an empty object...
// .buildFeatureList()
// .buildFeatureList({})
// .buildFeatureList({}, '*')
// -> data
//
// Build a list of features for a specific root feature and object...
// .buildFeatureList(object, feature)
// -> data
//
// Build a list of features for a specific set of root features and object...
// .buildFeatureList(object, [feature, ..])
// -> data
// NOTE: to disable a feature and all of it's dependants prefix
// it's tag with '-' in the list.
// e.g. including 'some-feature' will include the feature
// and its dependants while '-some-feature' will remove
// it and it's dependants.
//
//
// This will build from user input a loadable list of features taking
// into account feature dependencies, priorities and suggestions.
//
// Roughly this is done in this order starting with the given features:
// - include all dependencies (recursively)
// - include all suggested features (recursively)
// - sort features by priority
// - sort features by dependency
// - check for feature applicability
// - remove non-applicable features and all dependants (recursively)
// - remove disabled features and all dependants (recursively)
// - check and resolve exclusivity conflicts (XXX needs revision)
// - check for missing features and dependencies
//
//
// Return format:
// {
// // list of input features...
// input: [ .. ],
//
// // features in correct load order...
// features: [ .. ],
//
// // features disabled explicitly and their dependants...
// disabled: [ .. ],
// // unapplicable features and their dependants...
// unapplicable: [ .. ],
//
// // features removed due to exclusivity conflict...
// excluded: [ .. ],
//
// missing: {
// // features explicitly given by user but missing...
// USER: [ .. ],
// // missing <feature> dependencies...
// <feature>: [ .. ],
// ...
// },
// conflicts: {
// XXX
// },
// }
//
//
// NOTE: obj (action set) here is used only for applicability testing...
// NOTE: some feature applicability checks (.isApplicable(..)) may
// require a real action set, thus for correct operation one
// should be provided.
// NOTE: all feature sorting is done maintaining relative feature order
// when possible...
// NOTE: meta-features are not included in the list as they do not
// need to be setup.
// ...this is because they are not Feature objects.
//
// XXX should meta-features be MetaFeature objects???
// XXX not sure about handling excluded features (see inside)...
// XXX add dependency loops to .conflicts...
// XXX might be a good idea to check dependency loops on feature
// construction, too... (???)
buildFeatureList: function(obj, lst){
var that = this
obj = obj || {}
lst = (lst == null || lst == '*') ? this.features : lst
lst = lst.constructor !== Array ? [lst] : lst
var input = lst.slice()
var disabled = []
var excluded = []
var unapplicable = []
var missing = {}
var conflicts = {}
// reverse dependency cache...
var dependants = {}
// build dependency list...
var _buildDepList = function(n, seen){
seen = seen || []
return seen.indexOf(n) >= 0 ? []
: seen.push(n) && dependants[n] ? []
.concat.apply(
dependants[n],
dependants[n]
.map(function(n){ return _buildDepList(n, seen) }))
: []
}
// missing stage 1: check if all user included features exist...
// NOTE: we'll ignore missing disabled features too...
lst.forEach(function(n){
if(!that[n] && n[0] != '-'){
var m = missing['USER'] = missing['USER'] || []
m.push(n)
}
})
// include all dependencies...
//
// NOTE: this should never fall into an infinite loop as we do
// not include feature already seen...
// ...unless there is an infinite number of features, but
// I'll try to avoid that big a feature creep.
// XXX should we check for dependency loops here???
// ...this would have been simple if this was a recursion
// (just check if cur is in path), but here it is not
// trivial...
for(var i=0; i < lst.length; i++){
var k = lst[i]
// skip disabled or missing features....
if(k[0] == '-' || !that[k]){
continue
}
var deps = that[k].depends || []
var refs = that[k].suggested || []
deps.forEach(function(n){
// expand lst with dependencies....
lst.indexOf(n) < 0 && lst.push(n)
// build reverse dependency index...
var d = dependants[n] = dependants[n] || []
d.indexOf(k) < 0 && d.push(k)
})
// expand lst with suggenstions....
refs.forEach(function(n){
lst.indexOf(n) < 0 && lst.push(n)
})
}
// sort features by priority or position...
lst = lst
// remove undefined and non-features...
.filter(function(n){
// feature disabled -> record and skip...
if(n[0] == '-'){
disabled.push(n.slice(1))
return false
}
var f = that[n]
// feature not defined or is not a feature...
if(f == null || !(f instanceof Feature)){
return false
}
// check applicability...
if(f.isApplicable && !f.isApplicable.call(that, obj)){
unapplicable.push(n)
return false
}
return true
})
// remove disabled...
.filter(function(e){ return disabled.indexOf(e) < 0 })
// build the sort table: [ <priority>, <index>, <elem> ]
.map(function(e, i){ return [ that[e].getPriority(), i, e ] })
// do the sort...
// NOTE: JS compares lists as strings so we have to compare
// the list manually...
.sort(function(a, b){ return a[0] - b[0] || a[1] - b[1] })
// cleanup -- drop the sort table...
.map(function(e){ return e[2] })
// remove dependants on not applicable and on disabled...
var _unapplicable = unapplicable.slice()
var _disabled = disabled.slice()
// build the full lists of features to remove...
_unapplicable
.forEach(function(n){ _unapplicable = _unapplicable.concat(_buildDepList(n)) })
_disabled
.forEach(function(n){ _disabled = _disabled.concat(_buildDepList(n)) })
// clear...
// NOTE: in case of intersection disabled has priority...
lst = lst
.filter(function(n){
return _disabled.indexOf(n) >= 0 ?
disabled.push(n) && false
: _unapplicable.indexOf(n) >= 0 ?
unapplicable.push(n) && false
: true })
// missing stage 2: dependencies...
lst.forEach(function(k){
(that[k].depends || []).forEach(function(d){
// NOTE: we do not need to check disabled or unapplicable
// here as if the feature depended on dropped feature
// it would have been already dropped too...
if(!that[k]){
var m = missing[k] = missing[k] || []
m.push(d)
}
})
})
// check exclusive -> excluded...
//
// NOTE: this is the right spot for this, just after priority
// sorting and clearing but before dependency sorting.
//
// XXX do we need to clear dependencies pulled by excluded features???
// ways to go:
// - drop excluded and continue (current state)
// - disable excluded, add to original input and rebuild
// - err and let the user decide
var _exclusive = []
lst = lst.filter(function(n){
var e = that[n]
// keep non-exclusive stuff...
if(!e || e.exclusive == null){
return true
}
// count the number of exclusive features already present...
var res = e.exclusive
.filter(function(n){
if(_exclusive.indexOf(n) < 0){
_exclusive.push(n)
return false
}
return true
})
.length == 0
!res
&& excluded.push(n)
// warn the user...
// XXX not sure if this is the right place for this...
&& console.warn(
'Excluding unaplicable:', n, '(reccomended to exclude manually)')
return res
})
// sort by dependency...
var l = lst.length
// get maximum possible length...
// ...the worst case length appears to be (for full reversal):
// S(2*(n-1) + 1)
// S = n => n > 0 ? 2*(n-1)+1 + S(n-1) : 0
// S = n => n > 0 ? 2*n-1 + S(n-1) : 0
//
// 2 * S(n) - n
// S = n => n > 0 ? n + S(n-1) : 0
// f = n => 2 * S(n) - n
//
// N^2 + C
// S = n => n * n
//
// NOTE: this is the brute force way to check if we have a
// dependency loop, need something faster...
//
// XXX is O(n^2) good enough worst case here?
// ...at this point I think it is acceptable as we'll not
// expect dependency graphs too saturated, and the average
// complexity is far better...
var max = l * l
for(var i=0; i < lst.length; i++){
var k = lst[i]
var depends = that[k].depends || []
// list of dependencies to move...
var move = []
lst
.slice(0, i)
.forEach(function(n, j){
// if n is a dependency of k, prepare to move...
if(depends.indexOf(n) >= 0){
delete lst[j]
move.push(n)
}
})
// move the dependencies after k...
// NOTE: this will keep the order within the dependencies...
move.length > 0
&& lst.splice.apply(lst, [i+1, 0].concat(move))
// check for cyclic dependencies...
// XXX loop signs:
// - the tail length stops changing -- we stop progressing to list end
// - the loop is packed
// - each element includes a set of dependencies
// - this set is of the same length when at a specific element
// - we only shift the same set of N elements over N iterations
// - ...
if(lst.length >= max){
// XXX get the actual cycle...
console.error('Feature cyclic dependency...')
break
}
}
// cleanup after sort...
lst = lst
// remove undefined and non-features...
.filter(function(e){
return that[e] != null && that[e] instanceof Feature })
.reverse()
return {
input: input,
features: lst,
disabled: disabled,
unapplicable: unapplicable,
excluded: excluded,
missing: missing,
conflicts: conflicts,
}
},
//
// .setup(<actions>, [<feature>, ...])
// -> <actions>
//
// .setup([<feature>, ...])
// -> <actions>
//
setup: function(obj, lst){
// if no explicit object is given, just the list...
if(lst == null){
lst = obj
obj = null
}
obj = obj || (this.__actions__ || actions.Actions)()
lst = lst.constructor !== Array ? [lst] : lst
var features = this.buildFeatureList(obj, lst)
lst = features.features
// check for conflicts...
if(Object.keys(features.conflicts).length != 0
|| Object.keys(features.missing).length != 0){
var m = features.missing
var c = features.conflicts
// build a report...
var report = []
// missing deps...
Object.keys(m).forEach(function(k){
report.push(k + ': missing but required by:\n ' + m[k].join(', '))
})
report.push('\n')
// conflicts...
Object.keys(c).forEach(function(k){
report.push(k + ': must setup after:\n ' + c[k].join(', '))
})
// break...
throw 'Feature dependency error:\n ' + report.join('\n ')
}
// report excluded features...
if(this.__verbose__ && features.excluded.length > 0){
console.warn('Excluded features due to exclusivity conflict:',
features.excluded.join(', '))
}
// report unapplicable features...
if(this.__verbose__ && features.unapplicable.length > 0){
console.log('Features not applicable in current context:',
features.unapplicable.join(', '))
}
// do the setup...
var that = this
var setup = FeatureProto.setup
lst.forEach(function(n){
// setup...
if(that[n] != null){
this.__verbose__ && console.log('Setting up feature:', n)
setup.call(that[n], obj)
}
})
// XXX should we extend this if it already was in the object???
obj.features = features
return obj
},
remove: function(obj, lst){
lst = lst.constructor !== Array ? [lst] : lst
var that = this
lst.forEach(function(n){
if(that[n] != null){
console.log('Removing feature:', n)
that[n].remove(obj)
}
})
},
// shorthand for: Feature(<feature-set>, ...)
// XXX should this return this?
Feature: function(){
return this.__feature__.apply(null, [this].concat(args2array(arguments)))
},
}
var FeatureSet =
module.FeatureSet = object.makeConstructor('FeatureSet', FeatureSetProto)
//---------------------------------------------------------------------
var Features =
module.Features = new FeatureSet()
/**********************************************************************
* vim:set ts=4 sw=4 : */ return module })

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@ -2,12 +2,12 @@
"name": "features",
"version": "1.0.0",
"description": "",
"main": "index.js",
"main": "features.js",
"scripts": {
},
"repository": {
"type": "git",
"url": "git+https://github.com/flynx/features.git"
"url": "git+https://github.com/flynx/features.js.git"
},
"keywords": [
"js",