PHP-to-Javascript

A tool for converting simple PHP objects to Javascript code, so that code for manipulating objects can be used both server-side and client-side.

There is a page with a set of example code that can be [converted online here] (http://www.basereality.com/PHPToJavascript/) "PHP to Javascript conversion").

This is not meant to be use to convert arbitrary PHP code to Javascript as that is not possible due to differences between the two languages. It is meant to be used to write explicitly simple PHP code that can also be compiled to Javascript, rather than converting vast swathes of PHP to Javascript.

How to use

Examples

cd tests

php examples.php

This will convert the PHP files in the tests directory and for each write a javascript file equivalent.

Programmatically

• Install Composer from http://getcomposer.org/

• Add the "base-reality/php-to-javascript": ">=0.0.3" to your project's composer.json file:

  "require":{ "base-reality/php-to-javascript": "0.1.16" }

  Or the latest tagged version. The dev master should only be used for development, not production.

• Include the Composer SPL autoload file in your project:

  require_once('../vendor/autoload.php');

• Call the converter:

  $phpToJavascript = new PHPToJavascript\PHPToJavascript(); $phpToJavascript->addFromFile($inputFilename); $jsOutput = $phpToJavascript->toJavascript();

$jsOutput will now contain an auto-generated Javascript version of the PHP source file.

TODO

• Setup some automated testing.

• Add hasOwnProperty check to foreach loops.

• Add support for const to be same as public static.

• Figure out what to do about Javascript reserved keywords. Probably out to detect them and either warn or give an error on detection. testObject.delete();

• Support arrays for variables in class declaration.

• Add conversion of PHP array push to Javascript array push PHP => $withoutTags[] = false; JS => withoutTags.push(false);

• Add support for array with single element false; PHP => $withoutTags = array(false); JS => var withoutTags = {false};

• Statis class variables should be in class scope not the global one. SM PHPToJavascript\CodeConverterState_TSTRING token [T_STRING] => [ClassExample] SM PHPToJavascript\CodeConverterState_Default token [T_DOUBLE_COLON] => [::] SM PHPToJavascript\CodeConverterState_Default token [T_VARIABLE] => [$testStatic] SM PHPToJavascript\CodeConverterState_TVARIABLE token [T_VARIABLE] => [$testStatic] SM PHPToJavascript\CodeConverterState_TVARIABLEGLOBAL token [T_VARIABLE] => [$testStatic] Added variable testStatic to scope PHPToJavascript\GlobalScope

Limitations

There are several features of the PHP language that either are too difficult to map into Javascript, or are just not possible in Javascript. These features will almost certainly never be implemented (at least by myself) so if you're waiting for these to be done, give up early.

Pass scalars by reference

PHP allows you to pass scalar values by reference into a function. This feature does not exist in Javascript and so cannot be supported without a huge amount of effort.

Arrays passed by copy in PHP, by reference in Javascript

In PHP arrays are passed by copying the array into a function. In the converted Javascript, arrays are converted to objects and objects are passed by reference, so any modification to the parameter also modified the variable in the original scope - see.

Static class variables are always public

Due to the way objects in Javascript are implemented static class variables will always have public scope.

Defines are converted to value, but not defined in Javascript.

The code:

define('DATABASE_TYPE', 'MySQL');
echo "Database type is ".DATABASE_TYPE;

is converted to:

// define('DATABASE_TYPE', 'MySQL');
document.write( "Database type is " + 'MySQL');

If this is a problem for you - current solution is don't use defines. Instead use classes to define your const variables. It would be possible to add the define as a variable in the Global scope for Javascript. But that would be kind of sucky.

Associative arrays aren't ordered in Javascript.

In PHP an array will have the same order it's declared in e.g.

$testArray = array(
    'salutation' => 'Hello',
    ' ',
    'people' => 'world'
);

foreach($testArray as $string){
    echo $string;
}

Will output "Hello world". The equivalent in Javascript outputs " Helloworld" as the indexes aren't kept in order.

If you need arrays to stay in order you should use integer keys only.

Unset is fragile

The unset command in PHP works on any variable. PHP-To-Javascript converts it to the Javascript function delete, which only works on objects. This is okay for now as all arrays are currently created as objects, but it is a very fragile way of doing things. I would recommend not using unset, but instead copy out the values you want to keep into a new array.

List not supported

The PHP construct list is not supported.

Exception model is different

Javascript doesn't have a native way of catching different exception types, and doing different things with them. Although a different way of implementing this has been suggested, this isn't implemented yet and would require namespaces (which are also not implemented yet) to work.

Pull requests

For various reasons pull requests are not accepted on this project. If you find a bug please just open an issue. If there's an enhancement you'd like to see, please open an issue first to discuss it.