Support thumbnails

Hi Sam, I have been working with Vit on this patch and I think that we have gotten it as far as we are going to in this round of development. Vit has captured all of the main points above pretty well. I will recap on what has been done:

- An admin screen with API fields has been added to handle the downloading of the thumbnails. These fields are optional and will not break any sites which do not want to populate these fields.
- We have extended this functionality to also handle lazy loading of Brightcove videos. Once again, the autoplay video ID is optional and will not break any sites which do not want to fill it in.

The lazy loading functionality was added into the patch because it would have been hard to do this in two patches because both needed to work with the admin screen.

We think the patch is a big improvement and opens the way for pages with many Brightcove videos on them: the thumbnails are shown as the preview and then lazyload when the thumbnail is clicked.

We will be using this patch in production and will report back any problems or fixes we have.

I haven't been following this issue, but have bookmarked it and will take a squiz in the morning. Thanks!

Looking great, thanks for both working on this. While I have some feedback, this is a big improvement on the functionality. The module doesn't have a stable release, so I think we can continue to iterate on this stuff, as time allows.

Since more of the code in the module has been written by @kyberman than me at this point, I've also granted you permission to maintain the project. Feel free to push features/fixes and manage releases if you have capacity to do so.

Thanks!

1. --- /dev/null
   +++ b/config/install/video_embed_brightcove.settings.yml
   
   +++ b/config/install/video_embed_brightcove.settings.yml
   @@ -0,0 +1,3 @@
   
   @@ -0,0 +1,3 @@
   +client_id: ''
   +client_secret: ''
   +autoplay_player: ''
   

   This configuration should have associated schema definitions.

2. +++ b/src/Form/SettingsForm.php
   @@ -0,0 +1,145 @@
   +    // Check authentication if keys are provided.
   +    if (!empty($client_id) || !empty($client_secret)) {
   +      $auth_uri = 'https://oauth.brightcove.com/v4/access_token';
   +      $auth_string = base64_encode($client_id . ':' . $client_secret);
   +      $auth_options = [
   +        'headers' => [
   +          'Authorization' => 'Basic ' . $auth_string,
   +          'Content-Type' => 'application/x-www-form-urlencoded',
   +        ],
   +        'body' => 'grant_type=client_credentials',
   +      ];
   
   +++ b/src/Plugin/video_embed_field/Provider/Brightcove.php
   @@ -38,7 +92,60 @@ class Brightcove extends ProviderPluginBase {
   +    // Process authentication to get access token.
   +    $auth_uri = 'https://oauth.brightcove.com/v4/access_token';
   +    $auth_string = base64_encode($client_id . ':' . $client_secret);
   +    $auth_options = [
   +      'headers' => [
   +        'Authorization' => 'Basic ' . $auth_string,
   +        'Content-Type' => 'application/x-www-form-urlencoded',
   +      ],
   +      'body' => 'grant_type=client_credentials',
   +    ];
   +    $auth = $this->httpClient->request('POST', $auth_uri, $auth_options);
   +
   

   Here we repeat a lot of information, like the URL of the API, how to authorise with it, loading the credentials from configuration.

   This is a good candidate to split out into a seperate service. The service could have methods like canConnect and fetchRemoteThumbnail, which encapsulate the details of the API/auth within them.

3. +++ b/video_embed_brightcove.routing.yml
   @@ -0,0 +1,9 @@
   +  requirements:
   +    _permission: 'administer site configuration'
   

   I think we should define our own permission for this. This is quite broad.