Daniel Bachhuber 12:00 am on April 14, 2016  

RESTful WP-CLI – What I’ve been hacking on

Let me just say — Thursday, February 4th was pretty darn demoralizing. I spent a huge amount of time in January towards the WP REST APIREST API The REST API is an acronym for the RESTful Application Program Interface (API) that uses HTTP requests to GET, PUT, POST and DELETE data. It is how the front end of an application (think “phone app” or “website”) can communicate with the data store (think “database” or “file system”) https://developer.wordpress.org/rest-api/. in preparation for what I wanted to do on the command line, and a lot of momentum / inspiration / general good feelings were destroyed in that meeting. As such, I spent much of February and March working on WP-CLIWP-CLI WP-CLI is the Command Line Interface for WordPress, used to do administrative and development tasks in a programmatic way. The project page is http://wp-cli.org/ https://make.wordpress.org/cli/ features unrelated to the WP REST API (e.g. package management).

But, I’m back in the saddle. Because I’m 2/3 of the way through one of those fancy WP REST API + ReactReact React is a JavaScript library that makes it easy to reason about, construct, and maintain stateless and stateful user interfaces. https://reactjs.org/. WordPress applications, I’m running into dozens of ways I want to be able to make WordPress more efficiently. And of course, this means doing it on the command line.

Before we proceed: most of the, if not all, RESTful WP-CLI features have required under the hood changes to WP-CLI. You’ll want to wp cli update --nightly to play with this new functionality locally. Once you’ve done so, you can wp package install danielbachhuber/wp-rest-cli to install the latest.

Use --debug and --debug=rest to profile your REST endpoints

REST APIs are all about speed. Milliseconds matter, and every one you manage to shave off will have a real world impact on user experience.

To make it much, much easier to understand how many queries your endpoint is performing, and how long they take, I’ve added some lightweight profiling to RESTful WP-CLI.

Use --debug to get a summary of your queries for any command.

$ wp rest post list --debug
Debug (rest): REST command executed 7 queries in 0.001954 seconds. Use --debug=rest to see all queries. (1.446s)
+----+-----------------------------+
| id | title                       |
+----+-----------------------------+
| 1  | {"rendered":"Hello world!"} |
+----+-----------------------------+

Use --debug=rest to get the full list of queries executed.

$ wp rest post list --fields=id,title --debug=rest
Debug: REST command executed 7 queries in 0.001696 seconds. Ordered by slowness, the queries are:
1:
  - 0.000291 seconds
  - WP_REST_Posts_Controller->get_items, WP_Query->query, WP_Query->get_posts
  - SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AND (wp_posts.post_status = 'publish')  ORDER BY wp_posts.post_date DESC LIMIT 0, 10
2:
  - 0.000257 seconds
  - WP_REST_Posts_Controller->get_items, WP_Query->query, WP_Query->get_posts, WP_Query->set_found_posts
  - SELECT FOUND_ROWS()
3:
  - 0.000256 seconds
  - WP_REST_Posts_Controller->get_items, WP_REST_Posts_Controller->prepare_item_for_response, setup_postdata, WP_Query->setup_postdata, get_userdata, get_user_by, WP_User::get_data_by
  - SELECT * FROM wp_users WHERE ID = '1'
4:
  - 0.000244 seconds
  - WP_REST_Posts_Controller->get_items, WP_REST_Posts_Controller->prepare_item_for_response, setup_postdata, WP_Query->setup_postdata, get_userdata, get_user_by, WP_User->init, WP_User->for_blog, WP_User->_init_caps, get_user_meta, get_metadata, update_meta_cache
  - SELECT user_id, meta_key, meta_value FROM wp_usermeta WHERE user_id IN (1) ORDER BY umeta_id ASC
5:
  - 0.000233 seconds
  - WP_REST_Posts_Controller->get_items, WP_Query->query, WP_Query->get_posts, _prime_post_caches
  - SELECT wp_posts.* FROM wp_posts WHERE ID IN (1)
6:
  - 0.000209 seconds
  - WP_REST_Posts_Controller->get_items, WP_Query->query, WP_Query->get_posts, _prime_post_caches, update_post_caches, update_object_term_cache, wp_get_object_terms
  - SELECT t.*, tt.*, tr.object_id FROM wp_terms AS t INNER JOIN wp_term_taxonomy AS tt ON tt.term_id = t.term_id INNER JOIN wp_term_relationships AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id  WHERE tt.taxonomy IN ('category', 'post_tag', 'post_format') AND tr.object_id IN (1) ORDER BY t.name ASC
7:
  - 0.000206 seconds
  - WP_REST_Posts_Controller->get_items, WP_Query->query, WP_Query->get_posts, _prime_post_caches, update_post_caches, update_postmeta_cache, update_meta_cache
  - SELECT post_id, meta_key, meta_value FROM wp_postmeta WHERE post_id IN (1) ORDER BY meta_id ASC
 (1.598s)
+----+-----------------------------+
| id | title                       |
+----+-----------------------------+
| 1  | {"rendered":"Hello world!"} |
+----+-----------------------------+

Profiling works for any CRUD operation.

$ wp rest post create --title="Test post" --user=daniel --debug
Debug (rest): REST command executed 28 queries in 0.023962 seconds. Use --debug=rest to see all queries. (1.777s)
Success: Created post.
$ wp rest post update 3 --content="Foo bar" --user=daniel --debug
Debug (rest): REST command executed 31 queries in 0.023309 seconds. Use --debug=rest to see all queries. (1.634s)
Success: Updated post.

Hopefully this feature becomes an invaluable part of your REST endpoint development process, as it has mine. Hit me with feedback on its Github issue.

Use wp rest * edit to edit a resource in your system editor

Most people probably don’t know this, but you can use wp post edit <id> to edit post content in your system editor (e.g. vim). Now, with wp rest * edit, you can edit any REST resource in your system editor.

$ wp rest post edit 3 --user=daniel

When you run wp rest * edit, RESTful WP-CLI fetches the resource, transforms it into a YAML document, and puts it in your system editor:

---
date: 2016-04-14T14:02:57
date_gmt: null
password:
slug:
status: draft
title:
  raw: Test post
  rendered: Test post
content:
  raw: Foo bar
  rendered: |
    |
        Foo bar
excerpt:
  raw:
  rendered: |
    |
        Foo bar
author: 1
featured_media: 0
comment_status: open
ping_status: open
sticky: false
format: standard
categories:
  - 1
tags: [ ]

If you make changes to any of the fields, then the command sends it back to WordPress (through the WP REST API) to update.

On WordPress installs that support Basic Auth, editing also works over HTTPHTTP HTTP is an acronym for Hyper Text Transfer Protocol. HTTP is the underlying protocol used by the World Wide Web and this protocol defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands.:

$ wp --http=http://daniel:daniel@wordpress-develop.dev rest post edit 1

Et, voila.

Get involved!

I’d love your input on the dozens of ideas I have for a more RESTful WP-CLI:

  • Render the help docs in formats like APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways. Blueprint and Swagger [#36]
  • Introduce wp rest * generate to generate mock data in the format your application expects [#55].
  • Introduce wp rest * diff to be able to diff the state of two different WordPresses, a la Dictator [#56].
  • Figure out an elegant aliases implementation, so --http=http://daniel:daniel@wordpress-develop.dev becomes @wpdev [#2039]

And I want to hear your ideas too! As well as any feedback, questions, or violent dissent. Let’s chat on Github.