Rendering Views

View Scripts

Once you call render(), Zend\View\Renderer\PhpRenderer then include()s the requested view script and executes it "inside" the scope of the PhpRenderer instance. Therefore, in your view scripts, references to $this actually point to the PhpRenderer instance itself.

Variables assigned to the view, either via a View Model, Variables container, or by passing an array of variables to render(), may be retrieved in three ways:

• Explicitly, by retrieving them from the Variables container composed in the PhpRenderer: $this->vars()->varname.
• As instance properties of the PhpRenderer instance: $this->varname. (In this situation, instance property access is proxying to the composed Variables instance.)
• As local PHP variables: $varname. The PhpRenderer extracts the members of the Variables container locally.

We generally recommend using the second notation, as it's less verbose than the first, but differentiates between variables in the view script scope and those assigned to the renderer from elsewhere.

By way of reminder, here is the example view script from the PhpRenderer introduction.

<?php if ($this->books): ?>

    <!-- A table of some books. -->
    <table>
        <tr>
            <th>Author</th>
            <th>Title</th>
        </tr>

        <?php foreach ($this->books as $key => $val): ?>
        <tr>
            <td><?= $this->escapeHtml($val['author']) ?></td>
            <td><?= $this->escapeHtml($val['title']) ?></td>
        </tr>
        <?php endforeach; ?>

    </table>

<?php else: ?>

    <p>There are no books to display.</p>

<?php endif;?>

Escaping Output

One of the most important tasks to perform in a view script is to make sure that output is escaped properly; among other things, this helps to avoid cross-site scripting attacks. Unless you are using a function, method, or helper that does escaping on its own, you should always escape variables when you output them and pay careful attention to applying the correct escaping strategy to each HTML context you use.

The PhpRenderer includes a selection of helpers you can use for this purpose: EscapeHtml, EscapeHtmlAttr, EscapeJs, EscapeCss, and EscapeUrl. Matching the correct helper (or combination of helpers) to the context into which you are injecting untrusted variables will ensure that you are protected against Cross-Site Scripting (XSS) vulnerabilities.

// bad view-script practice:
echo $this->variable;

// good view-script practice:
echo $this->escapeHtml($this->variable);

// and remember context is always relevant!
<script type="text/javascript">
    var foo = "<?= $this->escapeJs($variable) ?>";
</script>