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Advance Techniques in PHP
1. Backtracing
2. Method Chaining
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Backtracing:debug_backtrace()
function bar() {print_r(debug_backtrace());}
bar('apple', 'banana', 'pear');[0] => Array (
[file] => /example.php[line] => 12[function] =>
foo[args] => Array ( [0] => apple [1] => banana [2]
=>pear ))
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Backtracing:debug_backtrace()
$backtrace =print_r(debug_backtrace(), true);This will email or
log the backtrace
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Backtracing:debug_print_backtrace()
If debug_print_backtrace() was calledin the same place in the
examplescript above in place ofdebug_backtrace() it would outputthe
following:
#0 bar() called at [-example.php:4]
#1 foo(apple, banana, pear) called at [-example.php:12]
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Capture the info fromdebug_print_backtrace
Using debug_print_backtracewith output
bufferingob_start();debug_print_backtrace();
$backtrace = ob_get_clean();
Using the Exception object$e = new Exception();$backtrace =
$e->getTraceAsString();
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Method Chaining A Typical Class
class Person{
private $m_szName;private $m_iAge;
public function setName($szName){
$this->m_szName = $szName;
}public function setAge($iAge){
$this->m_iAge = $iAge;}
public function getDetails(){
printf('Hello my name is %s and I am %d years
old.',$this->m_szName,
$this->m_iAge);}}
$p1 = new
Person();$p1->setName(Kumar');$p1->setAge(30);$p1->getDetails();
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Method Chaining class Person
{private $m_szName;private $m_iAge;
public function setName($szName){
$this->m_szName = $szName;
return $this; // We now return $this (the Person)}
public function setAge($iAge){
$this->m_iAge = $iAge;return $this; // Again, return our
Person
}
public function getDetails(){
printf('Hello my name is %s and I am %d years
old.',$this->m_szName,$this->m_iAge);
}}
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Using Method Chaining
$p1 = new Person();
$p1->setName(Kumar')->setAge(30)->getDetails();
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How it works
First up is $p1->setName(Kumar'). This assigns theperson's
name to be Kumar and returns $this -- thatis, the $p1 object. So at
the moment Kumar has hisname, but no age!
Next up comes ->setAge(30). Because we're chainedwith the
previous method, PHP interprets the codeand says "execute the
setAge method belonging towhatever was returned from the previous
method." Inthis case, PHP executes the setAge method belonging
to our Person object, $Kumar. Recall how we do use trim
functions
$x = ltrim(rtrim( Some String ));
Kumar S
