Bob's Blog

In the previous article, we looked at a technique to hide elements on the Create/Edit Resource page. The plugin was seriously flawed, however, since if it executed on other pages in the Manager, it might well hide things that shouldn't be hidden. In this article, we'll see a way to limit the execution of the plugin to specific actions.

The Method

If you look at the URL in your browser's address bar for various pages in the MODX Manager, you'll see that it always ends with something like this:

/manager/?a=element/plugin/update&id=5446

The part after the question mark is called the "query string" and it contains variables sent as part of a get request. That means that the variables and their values will be contained in the $_REQUEST array (which includes the $_GET array). You can see the full $_REQUEST array in the error log by putting this code in a plugin attached to OnManagerPageBeforeRender, and viewing any Manager page in the browser:

$modx->log(modX::LOG_LEVEL_ERROR, 'Request Array: ' . print_r($_REQUEST, true));

When you go to a page in the Manager where you would update an existing resource, this would appear in the error log:

[2016-07-12 01:58:18] (ERROR @ /addons/manager/index.php) Request Array: Array
(
    [a] => resource/update
    [id] => 5446
)

Notice the first element of the array. It contains the action MODX is performing — in this case resource/update. The Manager action will always be available in the plugin in the variable $_REQUEST['a']. We can use that to make sure the plugin will only execute on the appropriate pages.

The Improved Plugin

This plugin will only execute for the Create/Edit Resource panel:

$action = $_REQUEST['a'];

if ($action !== 'resource/create' && $action !== 'resource/update') {
   return;
}

if (! $modx->user->isMember('Administrator')) {
    $css = '
    <style>
        #ext-gen113 {
            display: none !important;
        }
    </style>
    ';

    $modx->regClientCSS($css);
}
return '';

The plugin code checks the action before executing. 'resource/create' or 'resource/update'. If it's not 'resource/create' and it's not 'resource/update', the plugin returns without doing anything.

Here is an alternate version for code purists who don't think a bit of code should have two return statements:

$action = $_REQUEST['a'];

if ($action == 'resource/create' || $action == 'resource/update') {
    if (! $modx->user->isMember('Administrator')) {
        $css = '
        <style>
            #ext-gen113 {
                display: none !important;
            }
        </style>
        ';

        $modx->regClientCSS($css);
    }
}
return '';

Notice that we've changed both equality tests to == and we've changed the logical connector from && (AND) to || (OR).

Here's yet another version that's a little more efficient:

$action = $_REQUEST['a'];

if (strpos($action, 'resource') !== false) {
    if (! $modx->user->isMember('Administrator')) {
        $css = '
        <style>
            #ext-gen113 {
                display: none !important;
            }
        </style>
        ';

        $modx->regClientCSS($css);
    }
}
return '';

The first if statement checks to see if the action contains 'resource'. The code inside it will only execute if it does. Since 'resource' appears in both 'resource/create' and 'resource/update', and no other actions on Manager pages will contain 'resource', the code should have the same effect as the versions above.

Coming Up

In the next article, we'll see how to hide the Static field for elements (Snippets, Plugins, Templates, TVs, and Chunks).

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For more information on how to use MODX to create a web site, see my web site Bob's Guides, or better yet, buy my book: MODX: The Official Guide.

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