Block Directory: Return deactivated plugins in search results.

[StevenDufresne]

Describe the bug
Inactive block directory blocks should return as installable in the search results. The block should be activated if the user decides to click Add Block again.

This functionality was removed in the transition to using the WP_REST_Plugins_Controller in #22454.

This feature was initially introduce in #22286.

To reproduce
Steps to reproduce the behavior:

1. Install a block from the directory (Boxer)
2. Disable plugin via wp-admin/plugins.php
3. Reload page
4. Search for the same block
5. Notice the result is not returned.

Expected behavior
See description.

Editor version (please complete the following information):

• WordPress version: current master

[StevenDufresne]

@TimothyBJacobs What do you think the best approach would be?

[TimothyBJacobs]

I think we can just remove the find_plugin_for_slug from the block directory controller. There is already a wp:plugin link generated. So we could follow that link an do a PUT { status: active }.

[TimothyBJacobs]

I've implemented that for trunk here, WordPress/wordpress-develop@7946dc6

When the block is already installed, you get a response like this.

{
    "name": "cgb\/block-p5js",
    "title": "p5.js Block",
    "description": "p5.js + WordPress. Want to share some generative art on your own WordPress site? This is the plugin to make it happen. Add your custom p5.js code, and preview it...",
    "id": "wp-p5js-block",
    "rating": 5,
    "rating_count": 3,
    "active_installs": 100,
    "author_block_rating": 5,
    "author_block_count": 1,
    "author": "Mark Uraine",
    "icon": "https:\/\/ps.w.org\/wp-p5js-block\/assets\/icon-128x128.png?rev=2026902",
    "assets": [
      "https:\/\/ps.w.org\/wp-p5js-block\/trunk\/dist\/blocks.build.js?v=1590645660",
      "https:\/\/ps.w.org\/wp-p5js-block\/trunk\/dist\/blocks.style.build.css?v=1590645660",
      "https:\/\/ps.w.org\/wp-p5js-block\/trunk\/dist\/blocks.editor.build.css?v=1590645660"
    ],
    "last_updated": "2020-05-28T06:01:00",
    "humanized_updated": "1 month ago",
    "_links": {
      "wp:install-plugin": [
        {
          "href": "http:\/\/trunk.test\/wp-json\/wp\/v2\/plugins?slug=wp-p5js-block"
        }
      ],
      "wp:plugin": [
        {
          "embeddable": true,
          "href": "http:\/\/trunk.test\/wp-json\/wp\/v2\/plugins\/wp-p5js-block\/plugin"
        }
      ],
      "curies": [
        {
          "name": "wp",
          "href": "https:\/\/api.w.org\/{rel}",
          "templated": true
        }
      ]
    }
  }

[TimothyBJacobs]

It would probably make sense to add an _embed=wp:plugin to the search request. That way you get the plugin details embedded.

{
    "name": "cgb\/block-p5js",
    "title": "p5.js Block",
    "description": "p5.js + WordPress. Want to share some generative art on your own WordPress site? This is the plugin to make it happen. Add your custom p5.js code, and preview it...",
    "id": "wp-p5js-block",
    "rating": 5,
    "rating_count": 3,
    "active_installs": 100,
    "author_block_rating": 5,
    "author_block_count": 1,
    "author": "Mark Uraine",
    "icon": "https:\/\/ps.w.org\/wp-p5js-block\/assets\/icon-128x128.png?rev=2026902",
    "assets": [
      "https:\/\/ps.w.org\/wp-p5js-block\/trunk\/dist\/blocks.build.js?v=1590645660",
      "https:\/\/ps.w.org\/wp-p5js-block\/trunk\/dist\/blocks.style.build.css?v=1590645660",
      "https:\/\/ps.w.org\/wp-p5js-block\/trunk\/dist\/blocks.editor.build.css?v=1590645660"
    ],
    "last_updated": "2020-05-28T06:01:00",
    "humanized_updated": "1 month ago",
    "_links": {
      "wp:install-plugin": [
        {
          "href": "http:\/\/trunk.test\/wp-json\/wp\/v2\/plugins?slug=wp-p5js-block"
        }
      ],
      "wp:plugin": [
        {
          "embeddable": true,
          "href": "http:\/\/trunk.test\/wp-json\/wp\/v2\/plugins\/wp-p5js-block\/plugin"
        }
      ],
      "curies": [
        {
          "name": "wp",
          "href": "https:\/\/api.w.org\/{rel}",
          "templated": true
        }
      ]
    },
    "_embedded": {
      "wp:plugin": [
        {
          "plugin": "wp-p5js-block\/plugin",
          "status": "active",
          "name": "p5.js Block",
          "plugin_uri": "https:\/\/github.com\/mapk\/p5js-block",
          "author": "Mark Uraine",
          "author_uri": "https:\/\/markuraine.com",
          "description": {
            "raw": "Add custom p5.js code into this Gutenberg block and preview it as you edit.",
            "rendered": "Add custom p5.js code into this Gutenberg block and preview it as you edit. <cite>By <a href=\"https:\/\/markuraine.com\">Mark Uraine<\/a>.<\/cite>"
          },
          "version": "1.1.0",
          "network_only": false,
          "requires_wp": "",
          "requires_php": "",
          "text_domain": "wp-p5js-block",
          "_links": {
            "self": [
              {
                "href": "http:\/\/trunk.test\/wp-json\/wp\/v2\/plugins\/wp-p5js-block\/plugin"
              }
            ]
          }
        }
      ]
    }
  }