PhpRenderer 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 simply by passing an array of variables to render()
– may be retrieved in three
ways:
- Explicitly, by retrieving them from the
Variables
container composed in thePhpRenderer
: $this->vars()->varname. - As instance properties of the
PhpRenderer
instance: $this->varname. (In this situation, instance property access is simply proxying to the composedVariables
instance.) - As local PHP variables: $varname. The
PhpRenderer
extracts the members of theVariables
container locally.
We generally recommend using the second notation, as it’s less verbose than the first, but differentiates between variables in the view script scope and those assigned to the renderer from elsewhere.
By way of reminder, here is the example view script from the PhpRenderer
introduction.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | <?php if ($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><?php echo $this->escapeHtml($val['author']) ?></td>
<td><?php echo $this->escapeHtml($val['title']) ?></td>
</tr>
<?php endforeach; ?>
</table>
<?php else: ?>
<p>There are no books to display.</p>
<?php endif;?>
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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.
1 2 3 4 5 6 7 8 9 10 | // 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 = "<?php echo $this->escapeJs($variable) ?>";
</script>
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