Magento 1.9 Best Practices – Using CDATA in JavaScript

best practicejavascriptmagento-1.9

<script type="text/javascript">
  //<![CDATA[
    Some code...
  //]]>
</script>

We agree that magento use the CDATA in javascript pieces codes, but I would like to know which is really the utility of this. There are some who say that we should put it in the XHTML and XML. So for exemple in some phtml, if i need to add a javascript function to validate some field or add a class etc … i should add the CDATA between the code or not necessarily.

Best Answer

I found also this answer:

It to ensure that XHTML validation works correctly when you have JavaScript embedded in your page, rather than externally referenced.

XHTML requires that your page strictly conform to XML markup requirements. Since JavaScript may contain characters with special meaning, you must wrap it in CDATA to ensure that validation does not flag it as malformed.

With HTML pages on the web you can just include the required JavaScript between and tags. When you validate the HTML on your web page the JavaScript content is considered to be CDATA (character data) that is therefore ignored by the validator. The same is not true if you follow the more recent XHTML standards in setting up your web page. With XHTML the code between the script tags is considered to be PCDATA (parsed character data) which is therefore processed by the validator.

Because of this, you can't just include JavaScript between the script tags on your page without 'breaking' your web page (at least as far as the validator is concerned).

Related Solutions

Magento 1.7 – Adding JavaScript to Head in Certain Pages

Add the following in your local.xml layout file (app/design/frontend/{interface}/{theme}/layout/local.xml) right under the <layout> tag this:
For product pages

<catalog_product_view>
    <reference name="head">
        <block type="core/text" name="some_name" as="some_name">
            <action method="setText">
                <text><![CDATA[YOUR TEXT GOES HERE]]></text>
            </action>
        </block>
    </reference>
</catalog_product_view>

For the checkout page is the same thing, except you need to replace the top tag with <checkout_onepage_index>. So the section above becomes:

<checkout_onepage_index>
    <reference name="head">
        <block type="core/text" name="some_name" as="some_name">
            <action method="setText">
                <text><![CDATA[YOUR TEXT GOES HERE]]></text>
            </action>
        </block>
    </reference>
</checkout_onepage_index>

it works the same for any other page. You just need to know the correct page handle (top tag). For index is cms_index_index, for cart is checkout_cart_index.

Magento – Begin & Commit – Lock rows to prevent user from receiving same code

I don't think your going to be able to handle this with the core database models. According to the MySQL Reference Manual, Locking Reads the type of query that your going to want to use is more like this:

SELECT * FROM codes WHERE used = 0 FOR UPDATE;
UPDATE codes SET used=1 WHERE id IN ( ...ids....);

You probably should use the transactions as well however.

I think your best approach is going to be to run queries directly against the database to give the functionality which you require.

    $query = "SELECT * FROM codes WHERE used = 0 FOR UPDATE";
    /**
     * Get the resource model
     */
    $resource = Mage::getSingleton('core/resource');

    /**
     * Retrieve the read connection
     */
    $readConnection = $resource->getConnection('core_read')->fetchOne($query);

From there your usual database operations can be applied and you can update the code generated for indicating it has been used and complete the transaction. Then the next person looking to get a code will be able to fit in and secure their unique codes.

(For a more indepth discussion of query handling please see this post: http://fishpig.co.uk/magento/tutorials/direct-sql-queries/)

Best Answer

Related Solutions

Magento 1.7 – Adding JavaScript to Head in Certain Pages

Magento – Begin & Commit – Lock rows to prevent user from receiving same code

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