PHP/Laravel Check a condition in a function only once - php

I have written a custom translation function for Laravel, which first checks a configuration variable to see whether to use Laravel's default __() function or my custom trans() function.
Here's my function:
function t($key, $replace = [], $locale = null)
{
$source = Config::get('translate.source');
if ($source == 'database') {
return trans($key, $replace, $locale);
} else {
return __($key, $replace, $locale);
}
}
However, for speed purposes, I don't want the if condition to run reach time I call the t() function, but only on the first call.
Any ideas?

You want to set a variable in the class and refer to that. So, create a variable databaseSource:
private $databaseSource = false;
You then want a method that will change the boolean:
function updateSource()
{
$source = Config::get('translate.source');
if ($source == 'database') {
$this->databaseSource = true;
}
$this->databaseSource = false;
}
You can then use this piece of functionality over and over via accessing the variable instead of getting the source every time you need it.
E.g. if ($databaseSource) { ... }

Related

How to call a function with other function as argument

im just learning php
Im trying to add a log with comments to my functions output.
Right now it looks like this:
//the function
function add1($x){
if($GLOBALS['logging'] === 'on'){ $log[] = 'Adding 1 to '.$x;};
$a = $x + 1;
if($GLOBALS['logging'] === 'on'){
$return[] = $a;
$return[] = $log;
return $return;
}else{ return $a; };
};
//calling the function
if($GLOBALS['logging'] === 'on'){
$return = add1($x);
$number = $return[0];
$log = $return[1];
}else{ $number = add1($x); };
Im kinda annoyed by the fact i need to retype this if statement.
So i made a seperate function for returning the function
which looks like this:
//function
function log_return($data = 'x', $log = 'x'){
if($GLOBALS['logging'] === 'on'){
if($data !== 'x') $return[] = $data;
if($log !== 'x') $return[] = $log;
return $return;
} return $data;
};//function end
And returning it with:
return $return = isset($log) ? log_return($data, $log) : log_return($data);
Now my quastion is: Is there a way to call a function with function..
like:
call_function(add1($x));
so i can return it either with log or without..
Given the answer https://stackoverflow.com/a/2700760/5387193 - this should work:
function add1($a)
{
// add1 code goes here
}
function call_function($name, $param)
{
$name($param);
}
call_function('add1', $x);
On a side note, your variable and function names aren't very intuitive. Perhaps you should study how to write good quality readable code. I recommend reading chapter 9 of Refactoring by Martin Fowler, it's quite good. You can find a PDF version on the web.
Another note, your return statement return $return = isset($log) ? log_return($data, $log) : log_return($data); has a unnecessary assignment to $return. The code should simply read
return isset($log) ? log_return($data, $log) : log_return($data);
Yes, it is possible. To simplify:
function first($x) {
return $x+1;
}
function second($y) {
return $y+1;
}
echo second(first(1)); // Returns 3, ie. 1+1+1
As gview said in his comment, don't use global variables. Argument lists exist for several reasons, included but not limited to making code easier to read, edit, and debug. The same goes for function and variable names.
Moreover, your code is very messy. It can be consolidated:
function addTo($currentValue, $valueToAdd, $logging = 0)
{
if ($logging) {
logWrite('addTo', "Adding $valueToAdd to $currentValue");
return $currentValue + $valueToAdd;
} else {
return $currentValue;
}
}
function logWrite($operation, $message)
{
$log = getLog(); // maybe it's a file, or DB record or something
// perform the write, depending on your implementation
}
$number = addTo($someStaringValue, $someOtherValue, 1);
All of this said, logging should not control program flow. In other words, whether something is logged by the system or not should have no bearing on what your code is trying to do. I really think you need to take a broader view of what you're trying to do and break it up into components.
At best, your code should tell a logger to log info, and the logger itself should determine if logging is actually turned on. If it is, the info is logged. If not, then the code that calls on the logger still works and goes about its business.

Variable scope - php - Using variables from one function in another

I am having trouble using a variable generated in one function, as a variable in a second function.
The Problem:
I get Notice: Undefined variable: parameter in the validate function, on the line:
$this->$methodName($item,$value,$parameter) OR $valid=false;
When the function call for splitRulesAndParameters is simply replaced with the code within the function, the problem goes away.
The Scenario:
The following two functions are both within the Validator class, the first, validate, makes use of the second, splitRulesAndParameters
Here is the validate function:
public function validate($data, $rules)
{
$valid= true;
foreach($rules as $item=>$ruleSet)
{
$ruleSetArray=explode('|',$ruleSet);
foreach($ruleSetArray as $rule)
{
$this->splitRulesAndParameters($rule);
$methodName='validate'.ucfirst($rule);
$value = isset($data[$item]) ? $data[$item] : NULL;
if(method_exists($this, $methodName))
{
$this->$methodName($item,$value,$parameter) OR $valid=false;
}
}
}
return $valid;
}
And here is the splitRulesAndParameters function
public function splitRulesAndParameters($rule)
{
$position = strpos($rule, ':');
if($position !==false)
{
$parameter = substr($rule,$position + 1);
$rule = substr($rule,0,$position);
}
else
{
$parameter='';
}
}
Seeing as the problem goes away if you "inline" the code in splitRulesAndParameters, I suspect the $parameters variable is used in that method. If so, simply have that method return the value of this variable, and assign it to a variable local to the validate method you've posted here:
$parameters = $this->splitRulesAndParameters($rule);
After adding this to the splitRulsAndParameters method:
return $parameters;
The method itself also modifies the $rule value. Again: this $rule variable is local to each method. It may have the same name, but the value is a copy. Any changes you make to $rule in splitRulesAndParameters is not reflected by $rule in your validate method. If I were you, I'd write:
public function splitRulesAndParameters($rule)
{
$position = strpos($rule, ':');
if($position !==false)
{
return array(
'parameter' => substr($rule, $position+1),
'rule' => substr($rule, 0, $position)
);
}
return array(
'parameter' => null,//no param == null, IMO, change to '' if you want
'rule' => $rule
);
}
Then, to change the variables in validate:
$split = $this->splitRulesAndParameters($rule);
$rule = $split['rule'];
$parameter = $split['parameter'];
That ought to do it.
Side-note:
You seem to be validating everything that needs validating, even if the first validation failed. If I were you, I'd change this fugly statement:
$this->$methodName($item,$value,$parameter) OR $valid=false;
To a more efficient:
if (!$this->{$methodName}($item, $value, $parameter))
return false;//if validation fails, return false
That stops any further valiation from being executed: if one value is invalid, then just stop there. To continue is pointless, because the data-set is not entirely valid anyway.
Bonus:
Using a colon to separate the method name, and some parameter(s) does allow you to specify multiple params, too, and it allows you to simplify the splitRulesAndParameters some more:
protected function splitRulesAndParameters($rule)
{
$all = explode(':', $rule);
return array(
'rule' => array_shift($all),//removes first element in array
'params' => $all//rest of the array
);
}
Tweak this a little to better suite your needs
You can't just use a variable from inside a function in another function. You have to return the variable $parameter. Add a return statement to the end of splitRulesAndParameters and store the result in a variable inside validate ($parameter = $this->spli...).
You actually have two problems here, because you change the &rule variable inside your function, but you are passing it by reference. So after the fucntion is done the $rule variable is the same as it was before.
The way to solve this in the manner you are doing it right now would be to change the function to:
public function splitRulesAndParameters(&$rule)
{
$position = strpos($rule, ':');
if($position !==false)
{
$parameter = substr($rule,$position + 1);
$rule = substr($rule,0,$position);
}
else
{
$parameter='';
}
return $parameter;
}
and change the line
$this->splitRulesAndParameters($rule);
to
$parameter = $this->splitRulesAndParameters($rule);

I need some help accessing a member function in a protected array in PHP

Right now I'm trying to write a function that would allow me to access member functions. The code in question looks a little like this:
protected $formName;
protected $formClass;
protected $formAction;
protected $formMethod;
protected $formObjArray = array(); //outputs in order. So far it should only take newLine, selectTag, inputTag, textTag.
protected $submitBtnVal;
protected $encType;
function __construct($args) {
$this->formName = $args['formName'];
$this->formAction = $args['formAction'];
if (isset($args['formClass'])) $this->formClass = $args['formClass'];
if (isset($args['encType'])) $this->encType = $args['encType'];
//default should be POST. Hell, you should never really be using GET for this..
//also, the default submit value is Submit
$this->formMethod = isset($args['formMethod']) ? $args['formMethod'] : "POST";
$this->submitBtnVal = isset($args['submitBtnVal']) ? $args['submitBtnVal'] : "Submit";
}
//get functions
function getFormName () { return $this->formName; }
function getFormAction () { return $this->formAction; }
function getFormMethod () { return $this->formMethod; }
function getSubmitBtnVal () { return $this->submitBtnVal; }
function getEncType () { return $this->encType; }
//set functions
function setFormName ($newName) { $this->fromName = $newName; }
function setFormAction ($newAction) { $this->formAction = $newAction; }
function setFormMethod ($newMethod) { $this->formMethod = $newMethod; }
function setEncType ($newEType) { $this->encType = $newEType; }
function addTag($newTag) {
if ($newTag instanceof formTag || $newTag instanceof fieldSetCont || $newTag instanceof newLine
|| $newTag instanceof noteTag)
$this->formObjArray[] = $newTag;
else throw new Exception ("You did not add a compatible tag.");
}
I'd like to be able to call $myForm->getTagByName("nameA")->setRequired(true);
How would I do that? Or would I need to do something more like..
$tagID = $myForm->getTagByName("nameA");
$myForm->tagArray(tagID)->setRequired(true);
Nothing in your code seems to be protected so you should have no trouble accessing any of it.
It looks like all your tags are in $formObjArray so it should be trivial to filter than array and return tags that match the name you've passed in. The trouble you will have is that, getTagByName really should be getTagsByName and should return an array because you can have more than one tag with the same name. Since it will return an array, you can not call setRequired on the return value, arrays don't have such a method. You'll need to do it more like:
$tags = $myForm->getTagsByName("nameA");
foreach ($tags as $tag) {
$tag->setRequired(true);
}
Exactly what are you stuck on? Maybe I don't understand the question very well.
So maybe the filtering has you stuck? Try this (if you you're using at least php 5.3)
function getTagsByName($tagname)
{
return array_filter($this->formObjArray, function($tag) use($tagname) {
return $tag->getName() == $tagname;
});
}
No ifs or switches.
Prior to 5.3, you don't have lambda functions so you need to do it differently. There are several options but this may be the simplest to understand:
function getTagsByName($tagname)
{
$out = array();
foreach ($this->formObjArray as &$tag) {
if ($tag->getName() == $tagname) {
$out[] = $tag;
}
}
return $out;
}
In your addTag method, you are storing new tags in $this->formObjArray using the [] notation, which will just append the new tag to the end of the array. If your tag objects all have a getName() method, then you can do something like this:
$this->formObjArray[$newTag->getName()] = $newTag;
Then, you can easily add a getTagByName() method:
public function getTagByName($name) {
if (array_key_exists($name, $this->formObjArray) {
return $this->formObjArray($name);
}
else {
return null;
}
}
Please beware of the solutions suggesting you to iterate through all the tags in your array! This could become very costly as your form gets larger.
If you need to use the [] construct because the order of the elements added is important, then you can still maintain a separate index by name, $this->tagIndex, that will be an associative array of name => tag. Since you are storing object references, they will not be using much space. Assuming that getTagByName will be used many times, this will save you a lot of resources over iterating the tags array on every call to getTagByName.
In that case, your addTag method would look like this:
$this->formObjArray[] = $newTag;
$this->tagIndex[$newTag->getName()] = $newTag; // it seems that you're doubling the memory needed, but you're only storing object references so this is safe
EDIT : Here is some modified code to account for the fact that multiple tags can have the same name:
In your addTag() method, do:
$this->formObjArray[] = $newTag;
$tag_name = $newTag->getName();
if (!array_key_exists($tag_name, $this->tagIndex)) {
$this->tagIndex[$tag_name] = array();
}
$this->tagIndex[$tag_name][] = $newTag
You can then rename getTagByName to getTagsByName and get the expected result.
As mentioned in the comments, this is only useful if you will call getTagsByName multiple times. You are trading a little additional memory usage in order to get quicker lookups by name.

Can I use a function to return a default param in php?

I would like to do something like this:
function readUser($aUser = loadDefaultUser()){
//doing read User
}
I find that it will display a error to me, how can I pass a function return as a default value? Thank you.
I would rather give a Null value for this argument and then call loadDefaultUser() in the body of the function. Something like this:
function readUser($aUser = NULL){
if(is_null($aUser)){
$aUser = loadDefaultUser();
}
//...
}
Yes, you can provide a default argument. However, the default argument "must be a constant expression, not (for example) a variable, a class member or a function call."
You can fake this behaviour by using some constant value for the default, then replacing it with the results of a function call when the function is invoked.
We'll use NULL, since that's a pretty typical "no value" value:
function readUser($aUser = NULL) {
if (is_null($aUser))
$aUser = loadDefaultUser();
// ... your code here
}
You can add a callback-parameter to your loadDefaultUser() function when it's finished it fires the callback function with the return/result. It's a bit like ajax-javascript callbacks.
function loadDefaultUser ( $callback )
{
$result = true;
return $callback($result);
}
function readUser($aUser = NULL){
if ($aUser === NULL){
$aUser = loadDefaultUser();
}
//do your stuff
}

PHP and DRUPAL, Cannot save values in a static variable and pass through function

Developing a module for drupal and I need to pass/modify variables within functions. I avoided using global variables because drupal uses the include function which subsequently makes my global variable into local.
As such, i created the following script which stores a static variable but I cannot retain the new value. Any help will be appreciated
function _example_set_flashurl($value = '21224', $clear = NULL) {
static $url;
if ($clear) {
// reset url variable back to default
$url = null;
}
// assigned url a perminate value within this function
$url = $value;
return $url;
}
function _example_get_flashurl() {
return _example_set_flashurl();
// retrieve the value inside set scope
}
_example_set_flashurl('another', TRUE);
print _example_get_flashurl(); // prints 21224, I want it to print another
Try this
<?
function _example_set_flashurl($value = '21224', $clear = NULL) {
static $url;
if ($clear) {
// reset url variable back to default
$url = null;
}
if($value!='21224') {
// assigned url a perminate value within this function
$url = $value;
}
return $url;
}
function _example_get_flashurl() {
return _example_set_flashurl();
// retrieve the value inside set scope
}
_example_set_flashurl('another', TRUE);
print _example_get_flashurl(); // prints 21224, I want it to print another
You override the value in the empty call to set in your get function.
First, you probably want to add the default value directly to the static and not the argument. Like this: "static $url = '21224';". Then, this value will also be returned when set has never been called.
Second, there is no need for a $clear argument if you can pass in any value you want. If you want to change it, just override the old value.
Third, as the answer from bruce dou showed, you want to protect it against accidently overriding the value.
So, this code for the set function should be all you need:
<?php
function _example_set_flashurl($value = FALSE) {
static $url = '21224';
// Only keep value if it's not FALSE.
if ($value !== FALSE) {
// assigned url a perminate value within this function
$url = $value;
}
return $url;
}
?>

Categories