Thursday, June 16, 2016

Porting custom module from Drupal 7 to Drupal 8 (databases, block view, URLs, and some menu work)

This is the next steps in getting my module working in Drupal 8. In the previous post, I got the block setup working, but it's just a generic "Hello World!" output. The block gets the most recent entries from a database table, so my next step is getting the database setup.

Databases

This doesn't seem to have changed from Drupal 7 to 8. You basically copy over the .install file. The hook_schema() takes care of it. BTW, one thing that is different is if you need to uninstall/reinstall the modules, you just need to drush pm-uninstall MODULE vs. drush dis MODULE ; drush pm-uninstall MODULE.

Once I had the database tables in place, I dumped my database tables from D7 and imported them into D8. NOTE: I probably need to either codify this (perhaps there's a way to hook into the migration system?) or keep notes about what tables to dump/import once everything's in place.

Now I needed to update my block to query the most recent entries in the table. db_query() is still supported in D8, however it looks like it's going away for D9, so if I wanted to future-proof my module even more, I could convert it to the new injection technique. So I created a storage class in my src folder. I downloaded the examples module and looked at the dbtng_example submodule and its DbtngExampleStorage class. I also found this answer on StackOverflow and the example posted in the select doc helpful. I ended up with a hybrid approach:

So a few things there. First, my post_date field was a legacy datetime field, so I had to convert the current time from a timestamp to the date format that mysql expected. format_date() is deprecated, so they recommend using Drupal::service('date.formatter'). Also, I make my __construct() method a little dynamic so that I don't have to pass in a connection, but it can support it if it is passed in.

Then my block build() method uses my storage class and calls the get_reports() method, passing in the block's configuration array. First, I add use Drupal\gated_content\GCStorage; to the top of my block plugin. Then my build() looks like this:
  public function build() {
    $storage = new GCStorage;
    $reports = $storage->get_reports($this->configuration);
    $build = array();
    kint($reports, $build);
    return $build;
  }

Block View

So now that my block has the right set of reports to show, I need to show them. This takes me to the whole theming and templates stuff. The D7 version called theme() directly and there was a hook_theme and I had a template. The end result was a simple
and foreach report, a
and l(); call to link to the report. Kind of reminds me of item_list a bit, so I think I'll start there.

Ok, it looks like item_list looks about the same. My render array just needs to '#theme' => 'item_list'. But l() is gone. This comment pointed me in the right direction. So now it looks like this:
    $items = array();
    foreach ($reports as $report) {
      $url = Url::fromRoute('');
      $items[] = \Drupal::l(t($report['title']), $url);
    }
    $build = array(
      'report_list' => array(
        '#theme' => 'item_list',
        '#items' => $items,
        '#attributes' => array(
          'class' => 'report-block',
        ),
      ),
    );
Success!

Of course, these all link to just the homepage, which isn't very helpful.

Menu

So now I'm looking down another rabbit hole. The URL to my report is reports/[ID#]. But I use this module on separate domains, so the reports part is configurable. So I need to get that configuration setting to get the first bit of the URL. Actually, I think I can skip that since we'll be doing something different in our migration plans, so I can skip that part of the module. [postnote: if I do end up needing this, it looks like this shows how]

Also, I had this module all setup with pathauto to get a nice SEO-friendly public URL. Ok, so I need to setup the menu routing so the user can get to /gated_content and /gated_content/[ID#] and /gated_content/[ID#]/download. And I need to setup pathauto again.

First, all of those URL's were setup in D7 with type of MENU_CALLBACK, so according to this doc, I need to set them up in a .routing.yml file. This wasn't something DMU setup for me, so I did this from scratch. This was a great doc that showed some examples going from D7 to D8.

My first question is that I was familiar with named placeholders and how the name would be used to call a NAME_load() function to put together the argument that gets passed into the callback. But these examples are using book, which uses node and entity, so I need something that will use my own data type.

Stuff for the next post!