ES|QL query builder

[miguelgrinberg]

This PR contains a prototype of an ES|QL query builder feature for the PHP client based on the one I built for the Python client.

Example usage:

$query = Esql\Query::from("books", "books*")
    ->where('author == "King"', 'year == 1982')
    ->limit(10);
echo $query;

Output:

FROM books, books*
| WHERE author == "King" AND year == 1982
| LIMIT 10

In IDEs, you get correct suggestions based on context. For example:

[ezimuel]

@miguelgrinberg thanks for the PR it looks interesting. The only comment that I've at the moment is to split each class in a separate file. The name of the file must be the same of the class. This is a best practices in PHP .

[miguelgrinberg]

@ezimuel I refactored into multiple files (one per class) and added a couple more commands now. Let me know if this structure seems reasonable and I'll add the remaining commands and all the docs.

Two usage examples:

use Elastic\Elasticsearch\Helper\Esql;

$query = Esql\Query::from("books", "books*")
    ->where('author == "King"', 'year == 1982')
    ->limit(10);
echo $query;

$query = Esql\Query::row(a: 123, b: "test")
    ->limit(1);
echo $query;

[miguelgrinberg]

@ezimuel This is ready to review!

Maybe what makes the most sense is for you to read the unit test file first, so that you see how all the commands are constructed.

[ezimuel]

Thanks @miguelgrinberg for this awesome PR! I just left a couple of comments, the most relevant that I would suggest to investigate is the possibility to use Traits instead of passing the parent in EsqlBase.
Moreover, we should add also some documentation about this helper with an example on how to call it using the Esql endpoint.

[ezimuel]

Maybe we can avoid using this function and avoid to pass the parent reference for each class using a Trait here. I used this mechanism for code reuse in the AbstractEndpoint to share common code on each Endpoint implementation.

[github-actions]

🔍 Preview links for changed docs

• docs/reference/esql.md

[github-actions]

The backport to 9.2 failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-9.2 9.2
# Navigate to the new working tree
cd .worktrees/backport-9.2
# Create a new branch
git switch --create backport-1462-to-9.2
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 a42e2dd906dbb27f7a263ae28538608463422363
# Push it to GitHub
git push --set-upstream origin backport-1462-to-9.2
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-9.2

Then, create a pull request where the base branch is 9.2 and the compare/head branch is backport-1462-to-9.2.