x-common

Build Status](https://travis-ci.org/x-component/x-common)

• ./common.js

./common.js

• undefined.extend()
• merge
• undefined.isNaN()
• undefined.flatten()

undefined.extend(target:, source_1...source_n:)

extend( target, source_1...source_n )

Extends a target object with properties from multiple source objects. Properties from source objects are added in the given order. Existing properties are overwritten. Note: Property values like objects and arrays are not cloned or copied.

example:

  t={a:1,b:2};
  s1={c:{y:'z'}};
  s2={d:3};
  r=extend(t,s1,s2,{e:4}); // => r is now { a:1,b:2,c:{y:'z'},d:3,e:4}
  r.a=5; // => t.a====5  is now also 5, as t i target
  r.d=6; // => s2.d====3, number is not an object and copied
  r.c.y='zz'; // ==> s1.y===='zz' is now also 'zz', as both point to the same object

when using

  extend(t,s1,s2,{e:4},true);

then

  r.c.y='zz'; // s1.y===='z'

you can use this to add properties to any object like functions or to an options object

merge

merge( target, source_1...source_n )

Merges multiple nested object structures into a single target object structure. It handles all enumaratable properties recursively.

• Arrays/objects from the sources are copied by a deep copy.
• null as a source property sets target obect/array/function property to null.
• Array like objects like arguments and dom lists are transformed into real arrays
• Arrays of sources are concatenated to target arrays
• Primitives and functions are added to arrays
• Object properties are merged as properties added to arrays.

So you can not add an object directly into an array, you have to use [] arround it
For the same reason you can not add null direclty into an array you must use [null]

• Functions from sources can define or replace target functions

• Functions from sources can not be merged/copied into a target objects,array, or primitives, they switch roles with the target.

• Thus merging for functions has side effects!

• Source objects properties can be merged into functions

• Arrays and primitives can not be merged into function, the source becomes an object with a single value before merging.

• Arrays and objects can not be merged into target primitives,

the target becomes an array or obect with a single value before merging.

To delete a property in a merge you can use a sepcial object as source: merge.remove

undefined.isNaN()

isNaN(value)

replacement for Number.isNaN as long as not all support this

undefined.flatten(object:)

flatten( object )

Flattens a nested object hierarchy to an single object with just non object values

example:

  flatten({a:{n:1,m:2},b:['x',{'y':'z'}],c:3})

result:

  {'a.n':1,'a.m':2,'b[0]':'x','b[1].y':'z',c:3}

recursive structures can not be flattened because paths would be endless