Replace string read from a file

Question

I’m creating a routine using the Symfony console to create new controllers from a pre-existing template file, but when searching for pattern defined in this template, the class SplFileObject jumps and sometimes skips a few lines;

public function writeWithTemplate($template)
{
    try {
        $this->template = new \SplFileObject(__DIR__ . "/templates/{$template}", "r");

        $pattern = '@' . strtoupper($template) . '@';

        while (!$this->template->eof()) {
            $this->file->fwrite($this->template->fgets());
        }
        return true;
    } catch(\Exception $error) {

        return false;
    }
}

the $this->file is also an open file using the SplFileObject, in this way that this function the same works perfectly, however if I make some comparisons within the while the write is not applied correctly.

the template file is:

<?php

namespace App\Controller;

use App\Controller\Controller;
use Psr\Http\Message\ServerRequestInterface as Request;
use Psr\Http\Message\ResponseInterface as Response;

class @CONTROLLER@ extends Controller
{

    public function main(Request $request, Response $response)
    {

    }
}

Note that there is a tag @CONTROLLER@ which is where I wish to do the substitution, if I do a check inside the while;

...
while (!$this->template->eof()) {
    if (strpos($this->template->fgets(), $pattern) !== false) {
       $line = str_replace($pattern, $this->fileName, $this->template->fgets());
    }         
    $line = empty($line) ? $this->template->fgets() : $line;
    $this->file->fwrite($line); 
}

Sometimes the generated file comes out only with } (1 or more) and several other meaningless combinations.

Answer 1

You may have more problems with your code, but one obvious is this:

Here you take a line and see if the Pattern is on that line:

if (strpos($this->template->fgets(), $pattern) !== false) {
//                          ^^^^^ leu uma linha

but then you picks up a new line and try to change the Pattern in this new:

   $line = str_replace($pattern, $this->fileName, $this->template->fgets());
   //                                                              ^^^^^ leu outra

That is, you are discarding most of the lines with the Pattern, and trying to change the Pattern on some line that doesn’t know if it really needs.

More sense would make that:

$line = $this->template->fgets();
if (strpos($line , $pattern) !== false) {
    $line = str_replace($pattern, $this->fileName, $line );
}

Actually, you need to see if it’s justified to have the if. Supposing it wasn’t something to be executed all the time, that’s all it would take:

while (!$this->template->eof()) {
    $line = $this->template->fgets();
    if(!empty($line)) $this->file->fwrite(str_replace($pattern, $this->fileName, $line));
}

Like it or not, the strpos has some cost. It is slightly less than the str_replace, but most likely the gain does not compensate in this scenario (I imagine that your generated file is the cache for normal use, and you only consume the template when there is some change).