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Improved Commenting
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@olifolkerd
olifolkerd committed Dec 20, 2015
1 parent 800f835 commit bd992c0
Showing 1 changed file with 134 additions and 32 deletions.
166 changes: 134 additions & 32 deletions Convertor.php
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Original file line number Diff line number Diff line change
Expand Up @@ -96,35 +96,51 @@ function defineUnits(){
"kwhr"=>array("base"=>"j", "conversion"=>3600000), //kilowatt hour
"mwhr"=>array("base"=>"j", "conversion"=>3600000000), //megawatt hour
"mev"=>array("base"=>"j", "conversion"=>0.00000000000000016), //mega electron volt


);
);
}

//constructor
/**
* Construt Object
*
* @param number $value - a numeric value to base conversions on
* @param string $unit (optional) - the unit symbol for the start value
* @return an instance of the Convertor object
*/
function __construct($value, $unit) {//

//create units array
$this->defineUnits();

//unit optional
if(!is_null($value)){

//set from unit
$this->from($value, $unit);
}

}

//set initial value again
/**
* Set from conversion value / unit
*
* @param number $value - a numeric value to base conversions on
* @param string $unit (optional) - the unit symbol for the start value
* @return none
*/
public function from($value, $unit) {
//unit optional

//check if value has been set
if(is_null($value)){
throw new Exception("Value Not Set");
}

if($unit){

//check that unit exists
if(array_key_exists($unit, $this->units)){
$unitLookup = $this->units[$unit];

//convert unit to base unit for this unit type
$this->baseUnit = $unitLookup["base"];
$this->value = $this->convertToBase($value, $unitLookup);
}else{
Expand All @@ -135,23 +151,31 @@ public function from($value, $unit) {
}
}

//run conversion to new unit
/**
* Convert from value to new unit
*
* @param string[] $unit - the unit symbol (or array of symblos) for the conversion unit
* @param int $decimals (optional, default-null) - the decimal precision of the conversion result
* @param boolean $round (optional, default-true) - round or floor the conversion result
* @return none
*/
public function to($unit, $decimals=null, $round=true){
//if no unit set in constructor workout base unit of to function
//if no decimals set return whole result

//check if from value is set
if(is_null($this->value)){
throw new Exception("From Value Not Set");
}

//check if to unit is set
if(!$unit){
throw new Exception("Unit Not Set");
}

//if unit is array, itterate through each unit
if(is_array($unit)){
return $this->toMany($unit, $decimals, $round);
}else{

//check unit symbol exists
if(array_key_exists($unit, $this->units)){
$unitLookup = $this->units[$unit];

Expand All @@ -166,20 +190,23 @@ public function to($unit, $decimals=null, $round=true){
$this->baseUnit = $unitLookup["base"];
}

//calculate value
//calculate converted value
if(is_callable($unitLookup["conversion"])){
// if unit has a conversion function, run value through it
$result = $unitLookup["conversion"]($this->value, true);
}else{
$result = $this->value / $unitLookup["conversion"];
}

//sort decimal rounding etc.
//result precision and rounding
if(!is_null($decimals)){
if($round){
$result = round($result, $decimals); //round to the specifidd number of decimals
//round to the specifidd number of decimals
$result = round($result, $decimals);
}else{
//truncate to the nearest number of decimals
$shifter = $decimals ? pow(10, $decimals) : 1;
$result = floor($result * $shifter) / $shifter; //truncate to the nearest number of decimals
$result = floor($result * $shifter) / $shifter;
}
}

Expand All @@ -190,23 +217,54 @@ public function to($unit, $decimals=null, $round=true){
}
}

//returns an array of conversion to all units with matching base units
/**
* Itterate through multiple unit conversions
*
* @param string[] $unit - the array of symblos for the conversion units
* @param int $decimals (optional, default-null) - the decimal precision of the conversion result
* @param boolean $round (optional, default-true) - round or floor the conversion result
* @return array - results of the coversions
*/
private function toMany($unitList = [], $decimals=null, $round=true){

$resultList = array();

foreach ($unitList as $key) {
//convert units for each element in the array
$resultList[$key] = $this->to($key, $decimals, $round);
}

return $resultList;
}


/**
* Convert from value to all compatable units
*
* @param int $decimals (optional, default-null) - the decimal precision of the conversion result
* @param boolean $round (optional, default-true) - round or floor the conversion result
* @return array - results of conversion to all units with matching base units
*/
public function toAll($decimals=null, $round=true){

//ensure the from value has been set correctly
if(is_null($this->value)){
throw new Exception("From Value Not Set");
}

//ensure the base unit has been set correctly
if($this->baseUnit){

$unitList = array();

//build array of units that share the same base unit.
foreach ($this->units as $key => $values) {
if($values["base"] == $this->baseUnit){
array_push($unitList, $key);
}
}

//convert units for all matches
return $this->toMany($unitList, $decimals, $round);

}else{
Expand All @@ -215,42 +273,79 @@ public function toAll($decimals=null, $round=true){

}

//return multiple conversions
private function toMany($unitList = [], $decimals=null, $round=true){

$resultList = array();

foreach ($unitList as $key) {
$resultList[$key] = $this->to($key, $decimals, $round);
}

return $resultList;

}

//add conversion unit
/**
* Add Conversion Unit
*
* @param string $unit - the symbol for the new unit
* @param string $base - the symbol for the base unit of this unit
* @param number/function() - the conversion ration or conversion function from this unit to its base unit
* @return boolean - true - if successfull
*/
public function addUnit($unit, $base, $conversion){
//throw new Exception('Base Unit Does Not Exist");

//check that the new unit does not ealread exist
if(array_key_exists($unit, $this->units)){
throw new Exception("Unit Already Exists");
}else{
//make sure the base unit for the new unit exists or that the new unit is a base unit itself
if(!array_key_exists($base, $this->units) && $base != $unit){
throw new Exception("Base Unit Does Not Exist");
}else{
//add unit to units array
$this->units[$unit] = array("base"=>$base, "conversion"=>$conversion);
return true;
}
}

}

//returns and array of units available for given unit, empty value returns all units

/**
* Remove Conversion Unit
*
* @param string $unit - the symbol for the unit to be removed
* @return boolean - true - if successfull
*/
public function removeUnit($unit){
//check unit exists
if(array_key_exists($unit, $this->units)){

//if unit is base unit remove all dependant units
if($this->units[$unit]["base"] == $unit){
foreach ($this->units as $key => $values) {
if($values["base"] == $unit){
//remove unit
unset($this->units[$key]);
}
}

}else{
//remove unit
unset($this->units[$unit]);
}

return true;

}else{
throw new Exception("Unit Does Not Exist");
}
}

/**
* List all available conversion units for given unit
*
* @param string $unit - the symbol to search for available conversion units
* @return array - list of all available conversion units
*/
public function getUnits($unit){
//check that unit exists
if(array_key_exists($unit, $this->units)){
//find base unit
$baseUnit = $this->units[$unit]["base"];

$unitList = array();

//find all units that are linked to the base unit
foreach ($this->units as $key => $values) {
if($values["base"] == $baseUnit){
array_push($unitList, $key);
Expand All @@ -263,10 +358,17 @@ public function getUnits($unit){
}
}

//convert value to base unit
/**
* Convert from value to its base unit
*
* @param number $value - from value
* @param array $unitArray - unit array from object units array
* @return number - converted value
*/
private function convertToBase($value, $unitArray){

if(is_callable($unitArray["conversion"])){
// if unit has a conversion function, run value through it
return $unitArray["conversion"]($value, false);
}else{
return $value * $unitArray["conversion"];
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