# SS_DAG

class
**SS_DAG** implements
IteratorAggregate (View source)

A Directed Acyclic Graph - used for doing topological sorts on dependencies, such as the before/after conditions in config yaml fragments

## Methods

__construct($data = null)

No description

additem($item)

Add another node/vertex

addedge($from, $to)

Add an edge from one vertex to another.

array

sort()

Sort graph so that each node (a) comes before any nodes (b) where an edge exists from a to b

getIterator()

No description

## Details

###
```
```**__construct**($data = null)

**__construct**($data = null)

###
```
```**additem**($item)

**additem**($item)

Add another node/vertex

###
```
```**addedge**($from, $to)

**addedge**($from, $to)

Add an edge from one vertex to another.

When passing actual nodes (as opposed to indexes), uses array_search with strict = true to find

###
```
array
```**sort**()

**sort**()

Sort graph so that each node (a) comes before any nodes (b) where an edge exists from a to b

###
```
```**getIterator**()

**getIterator**()