John Bickar's Blog Posts

If you spend a lot of your day at the command line (as I do), you're constantly on the lookout for new tools and tricks to increase your productivity and efficiency. Today we're going to take a look at the pushd suite of commands that exist in most shells (e.g., bash, tcsh and so forth).

What Do These Commands Do?

pushd, dirs, and popd help you move around your directory structure more efficiently. In short, they are cd on steroids.

Command Usage

cd

cd is pretty straightforward, and limited. cd <directoryname> to switch to that directory; cd - to switch back to where you were previously.

pushd

pushd allows you to save a series of directories in your history, and later navigate back to any directory in the history. It also echoes, in a single line, what's in the history (or "stack"):

The above command, pushd /Applications, set /Applications as my current working directory, and echoed back the two directories in the stack, /Applications and ~, separated by a space.

Add a few more locations into the stack by using pushd some more:

dirs

Use the dirs command to view what's in your history.

Then use pushd +n to navigate to the nth item in your history:

popd

Use popd to remove the top location in the history (which is index 0, or where you currently are) and return to the previous location (which is index 1):

Thanks to JB Christy in University Communications for introducing me to the pushd commands!

Further Reading

• pushd, popd, and dirs (from Softpanorama)

Today's "Module of the Day" is a handy little module called JS Injector that allows you to insert snippets of Javascript into your site.

In this post, I'll walk through how to enable and configure the module, use it to shout, "Hello, World!", and then go into some more advanced configuration.

Enable the Module

To use the module, you must enable it. This module has recently been installed on Stanford Sites and does not get enabled by default.

Go to admin/modules, check the box for "JS Injector", and click save.

(What's that fancy user interface at admin/modules? That's Module Filter.)

Add a JS Injector Rule

Go to admin/config/development/js-injector and click the "+Add" link (or go directly to admin/config/development/js-injector/add):

Creating a "Hello World" JS Injector Rule

Create a new rule with the following settings:

• Friendly name: hello_world
• Description: Greets the world
• JS Code:
  
  alert('Hello, World!');
• Placement Options
  • Position of the javascript: Usually you would want to leave this set to "header"
  • Preprocess JS: For development and testing purposes, leave this unchecked; once your Javascript code is finalized and your site is in production, check this box
  • Inline JS: Usually you would want to leave this unchecked
• Pages: Choose "The listed pages only", and enter "<front>" in the text box. This will run the Javascript only on the front page.

Then save the rule.

See Your JS Injector Rule in Action

Go to your home page and get your greeting!

Doing More With JS Injector

So now you have a "Hello, World!" alert greeting you every time you open your front page. You may think you have reached the pinnacle of human achievement on the Intertubes, but there is, in fact, more that you can do with JS Injector. (Go ahead and delete your "Hello World" JS Injector rule, as a service to humanity.)

Use Some jQuery

Drupal bundles jQuery with default installs, and that means you can use jQuery functions and selectors to select and manipulate elements in the DOM.

Add a new JS Injector rule and use the following Javascript/jQuery code:

And set it to display on the front page.

Load your front page and inspect the <h2> element and see that it has the class="awesomesauce" attribute:

You can use the full range of jQuery functions in JS Injector. Just remember to wrap your jQuery code in jQuery(document).ready(function($) {}); like so:

The modern Web is a dynamic place. However, sometimes it's necessary (or desirable) to remove the dynamic functionality of a website, while preserving its static content.

Inspired in part by Karen Stevenson's excellent blog post, "Sending a Drupal Site into Retirement," I wanted to outline a few other techniques for accomplishing this.

Reasons you may want to create a static copy of a site:

• The site runs on an outdated version of dynamic web software
• The site has been hacked, but its content is still relevant
• The site's content has lost its immediacy, but may need to be revived in the future as a dynamic website
• The site was built in 2004 in ColdFusion by a vendor that has flown the coop (oops)

Method One: wget

Wget is a cross-platform command-line program for retrieving web pages. It's almost like it was built to do this.

Run the following code to crawl www.example.com and save it as flat files to an arbitrary directory of your choosing (noted by /path/to/destination/directory):
 wget -P /path/to/destination/directory/ -mpck --user-agent="" -e robots=off --wait 1 -E <a href="https://www.example.com/">https://www.example.com/</a>

See this code explained on explainshell

More Information for the Stanford Web Environment

If you have a Drupal, WordPress, or MediaWiki site hosted on the Stanford WWW servers (AKA "AFS"), you can use the wget method to create a static copy of your site in cgi-bin.

Assuming you have a site at http://ponies.stanford.edu and it lives at /afs/ir/group/ponies/cgi-bin/drupal.

1. SSH into corn.stanford.edu
2. Run the following command:
    wget -P /afs/ir/group/ponies/WWW/ -mpck --user-agent="" -e robots=off --wait 1 -E <a href="http://ponies.stanford.edu/">http://ponies.stanford.edu/</a>
3. Visit http://www.stanford.edu/group/ponies/ponies.stanford.edu in a browser; you should have a full copy of your production site
4. You may have to do some cleanup of the HTML code, and may want to rename the directory using the following command:
   mv /afs/ir/group/ponies/WWW/ponies.stanford.edu /afs/ir/group/ponies/WWW/static
5. Once you've checked everything out and it looks good, you can submit a Virtual Host change request so that ponies.stanford.edu points at www.stanford.edu/group/ponies/static
6. If you want to then delete the dynamic site, submit a HelpSU request.
7. Note: if the site is a Drupal site, you may want to disable CSS and Javascript aggregation, so that wget will grab the original source versions of those files

Method Two: Drupal's "Disable All Forms" Module

If it's a Drupal site, you can use the Disable All Forms Module. This module does exactly what it says: it disables all forms. Using it requires Bad Judgement (sic).

This method works well if you may want to revive the Drupal site at some point in the future, but don't want to deal with spammers and other malcontents.

Method Three: WordPress Plugin

There are a variety of WordPress plugins to create a static copy of a WordPress site.

See Also

• Sending a Drupal Site Into Retirement
• Creating a static archive of a Drupal site

In Drupal development land, the theme is what controls the final HTML, CSS, and Javascript that get delivered to the browser.

Sometimes, however, in developing a custom module, you want to provide a suggestion for an HTML framework, and not rely on the theme's default implementation of a given block of HTML.

You may ask yourself:

Can I use .tpl.php files in a Drupal module?

(And you may ask yourself, "How do I work this?", and you may ask yourself, "Where is that large automobile?")

Enter hook_theme_registry_alter()

Drupal's API includes a nifty function named hook_theme_registry_alter(). This hook allows you to - wait for it - alter the theme registry. The theme registry "maintains cached data on the available theming hooks and how to handle them". By altering the theme registry, you can tell Drupal to look elsewhere for theme templates (e.g., *.tpl.php files).

See What's in the Theme Registry

1. Install and enable the Devel module
2. Call dpm($theme_registry) in your custom module:
   
   
   function mymodule_theme_registry_alter(&$theme_registry) {
     dpm($theme_registry);
   }
                  

3. Clear your theme-registry cache: drush cc theme-registry

4. Reload the page, and you then get a nice Krumo display of the entire $theme_registry array.

   

5. In this case, we want to override the search page "no results" language (which has been the subject of contentious debate) with a custom template.
   
6. $theme_registry['search_results'] looks like this:
   
   
   Array
   (
       [variables] => Array
           (
               [results] =>
               [module] =>
           )

       [file] => search.pages.inc
       [template] => modules/search/search-results
       [type] => module
       [theme path] => modules/search
       [includes] => Array
           (
               [0] => modules/search/search.pages.inc
           )

       [preprocess functions] => Array
           (
               [0] => template_preprocess
               [1] => template_preprocess_search_results
               [2] => contextual_preprocess
           )

       [process functions] => Array
           (
               [0] => template_process
               [1] => rdf_process
           )

   )

   

Alter the Theme Registry

We're going to override that setting in the theme registry, and tell the theme system to look in our custom module (named "mymodule") for a template:

Our search-results.tpl.php file looks like this:

The Results

Now our $theme_registry['search_results'] looks like this:

And our search results page looks like this:

Note that "bike shed" has been replaced by "stanford university"

See Also

• https://drupal.org/node/715160
• Stanford Sites Helper module - a further example of hook_theme_registry_alter() in action