Simple templating with str_replace

I'm just experimenting first of all.

I just came up with an idea of making my own in a simple way here:

class Template
{
    function pars开发者_开发技巧e($template_file, $braces)
    {
        if(file_exists($template_file))
        {
            $template = file_get_contents($template_file);

            foreach($braces as $brace => $replacement)
            {
                $brace = trim(strtoupper($brace));
                $build = str_replace('{' . $brace . '}', $replacement, $template);
            }

            echo $build;
        }
        else
        {
            trigger_error('Template file does not exist: ' . $template_file, E_ERROR);  
        }
    }
}

This in order to work:

$template = new Template();

$template->parse('index_body.html', array('ONE' => 'one',
                                          'TWO' => 'two',
                                          'THREE' => 'three'));

index_body.html:

{ONE}
{TWO}
{THREE}

The problem is, that it only outputs:

{ONE} {TWO} three

It always replaces the last brace, how come not the whole array?

$build = str_replace('{' . $brace . '}', $replacement, $template);
                                                       ^^^^^^^^^

You're always replacing against the original template, never against the updated one. Either keep assigning $template, or update $build

$template = file_get_contents($template_file);

$build = $template;

foreach($braces as $brace => $replacement)
                {
                    $brace = trim(strtoupper($brace));
                    $build = str_replace('{' . $brace . '}', $replacement, $build);
                }

It only replaces the last place because in each case, you're replacing the value in the original $template variable. It's not updating the variable each iteration.

You echo $build, which is being reassigned every foreach iteration.

You should've written this instead

 $template = str_replace('{' . $brace . '}', $replacement, $template);

How about using like full php engine power (similar to smarty interface): just for experimenting:

class Template {
    private $_file;
    private $_variables = array();

    public function __construct($file = null) {
        $this->_file = $file;
    }

    public function set($key, $value) {
        $this->_variables[$key] = $value;
    }
    public function fetch($file = null) {
        if (!$file) {
            $file = $this->_file;
        }

        extract($this->_variables);
        ob_start();

        require($file);

        $content = ob_get_contents();

        ob_end_clean();

        return $content;
    }

    public function display($file = null) {
        if (!$file) {
            $file = $this->_file;
        }

        $result = $this->fetch($file);

        echo $result;
    }
}

=============

$tpl = new Template('hello.tpl');
$tpl->set('world', 'earth');
$tpl->display();

=============
Template sample:hello.tpl

Hello <?=$world;?>

Your $build is overwritten in each iteration. This will solve the issue.

class Template
{
    function parse($template_file, $braces)
    {
        if(file_exists($template_file))
        {
            $template = file_get_contents($template_file);

            foreach($braces as $brace => $replacement)
            {
                $brace = trim(strtoupper($brace));
                $temp = str_replace('{' . $brace . '}', $replacement, $template);//create a temporary array
                $build  = array_merge($build ,$temp);
            }

            echo $build;
        }
        else
        {
            trigger_error('Template file does not exist: ' . $template_file, E_ERROR);  
        }
    }
}