Question

Recently I’ve been busy with some PHP framework – completely off-topic by the way.

Anyhow, I got specific html/template files I would like to parse with C++ (don’t ask me why, it’s just because I want to write it in C++). Besides that, it might actually be the first useful thing I would ever write in C++.

Anyway, to get back to the problem, imagine I have a file like the following:

<table>
    <tr>
        <th>ID</th>
        <th>Title</th>
        <th>Actions</th>
    </tr>
    {foreach from="$pages => $page"}
    <tr>
        <td>{$page.Id()}</td>
        <td>{$page.Title()}</td>
        <td><a href="page/edit/{$page.Id()}/">Edit</a> | <a href="page/delete/{$page.Id()}/">Delete</a></td>
    </tr>
    {foreachelse}
    <tr>
        <td colspan="3">There are no pages to be displayed</td>
    </tr>
    {/foreach}
</table>

And the output should be:

<table>
    <tr>
        <th>ID</th>
        <th>Title</th>
        <th>Actions</th>
    </tr>
    <?php if(count($pages) > 0): ?>
    <?php foreach($pages as $page): ?>
    <tr>
        <td><?php echo $page->getId(); ?></td>
        <td><?php echo $page->getTitle(); ?></td>
        <td><a href="page/edit/<?php echo $page->getId(); ?>/">Edit</a> | <a href="page/delete/<?php echo $page->getId(); ?>/">Delete</a></td>
    </tr>
    <?php endforeach; ?>
    <?php else: ?>
    <tr>
        <td colspan="3">There are no pages to be displayed</td>
    </tr>
    <?php endif; ?>
</table>

Why I am doing this might not be exactly clear to you, but it remains a problem, applicable somewhere else in any case.

Anyhow, some forward and backward lookups and modifications in the output files are required. What is the right approach to this problem?

Answer 1

For these type of problems I tend to be inclined towards REGEX. Using either boost::regex or the GNU regex classes or any other library. Identifying those markers and converting them is mostly a regex search and replace thing (with parameters for variable names, values, etc.), and you don’t have to write code to actually parse the complete HTML and the special inserts.