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Osm Admin: Current Goal. Combining ElasticSearch And MySql. Rendering Faceted Navigation

2022 March Osm Admin

6 months ago ∙ 4 minutes read

My current goal is a minimum list page, a form page and a faceted navigation for a Product data class.

Today, I've:

  • implemented ElasticSearch + MySql combo that gets the list page data
  • started rendering the faceted navigation

More details:

P.S. Feel free to DM me if anything is unclear, or you want to discuss it, or help.

Goal

My current goal is to create some minimum admin UI that actually works. As an example,

I've picked the Product class having standard id and title properties, and one custom color property that can be assigned one of predefined color values.

List Page

Product list page will show up as a multiselect grid with title and color columns. Clicking on a grid row will open an editing page for the clicked product.

The faceted navigation in the sidebar will contain a single color filter show counts for every option based on currently shown product set. You'll be able to filter by one or more color values, and see matching product list, and a list of applied filters.

Buttons:

  • Create button will show a new product page.
  • Edit button will show an editing page for one or more selected products.
  • Delete button will delete one or more selected products.

Form Pages

The new product page, and the product editing page will show the same form with title input, and color dropdown.

The same faceted navigation will be shown in the sidebar.

Buttons:

  • Close button will return you to the list page.
  • Save button will save new or edited product(s).
  • Delete button will delete edited product(s).

Status

I've already had the list page showing the products, and now I'm working on the faceted navigation in the sidebar.

For it to work, I created the underlying index in the ElasticSearch. Currently, the only way to update it is to fully rebuild it using osm index command.

Well, it will be osm index in the product that use Osm Admin. While developing Osm Admin the exact command is php bin/run.php index.

Now it's time to implement querying the color facet, and display it in the sidebar.

Currently, the list page shows 'Osm\Admin\Ui\Query::runSearchAndDb()' not implemented exception. This is where I am.

Ui\Query is a class responsible for retrieving the data both for the grid (Ui\List_\Grid class), and for the faceted navigation in the sidebar (Ui\Facets class). The rendering is done in three steps:

  1. Both grid and faceted navigation objects tell the UI query object what columns and facets should be shown, and what filters should be applied.
  2. The UI query object retrieves the data from the database and the search engine.
  3. Grid and faceted navigation objects render the data to HTML using Blade templates.

If no facets are being rendered, the UI query only queries the database. This scenario (without applying filters) is already implemented.

Otherwise:

  1. It retrieves matching product IDs and facet counts.
  2. It uses these product IDs to retrieve product properties from the database.

The search+database scenario is yet to be implemented.

Implementing Search + DB Queries

OK, let's implement it:

// Ui\Query

protected function run(): void
{
    if ($this->executed) {
        return;
    }

    if (!empty($this->query_facets)) {
        $this->runSearchAndDb();
    }
    else {
        $this->runDb();
    }

    $this->executed = true;
}

protected function runSearchAndDb(): void {
    $searchQuery = $this->searchQuery();

    foreach (array_unique($this->query_facets) as $propertyName) {
        $searchQuery->facetBy($propertyName);
    }

    $searchResult = $searchQuery->get();

    $this->count = $searchResult->count;
    $this->facets = $searchResult->facets;

    $this->items = count($searchResult->ids)
        ? $this->dbQuery()
            ->where("id IN (" .
                implode(', ', $searchResult->ids). ")")
            ->get(...array_unique($this->query_selects))
        : [];
}

protected function runDb(): void {
    if ($this->query_count) {
        $this->count = $this->dbQuery()->value("COUNT() AS count");
    }

    if ($this->query_items) {
        $this->items = $this->dbQuery()
            ->get(...array_unique($this->query_selects));
    }
}

This implementation lacks several things:

  • it doesn't apply any filters, orders, limit or offset
  • search index always return count and items even if they are not needed
  • consistency. Search query returns a separate object with the results while UI query assigns results to the same query object.

I'll address these issues later. Now, I have a more urgent one.

Parsing Formulas

Previously, the Grid requested data for its columns like this:

$this->query->db_query->select(...$this->selects);

Now, it's changed to

$this->query->select(...$this->selects);

New implementation stores select formulas as text in the Ui\Query object, and passes them to the underlying DB query when query is actually executed.

However, the Grid object needs these formulas parsed, as it needs to know the schema information about the selected property, and decide how to render each column.

On the other hand, I still want to avoid parsing the same formulas two times instead of one.

The solution is having an internal Query object using it to parse formulas passed to Ui\Query::select().

And yes, it's time to separate query data and duery result data into two separate objects.

Facet Visibility

Query returns facet counts. The next step is to render them on the list page.

Facets are rendered in the sidebar. If there are no facets, the sidebar is not shown (ui::layout Blade template):

@if(!empty($sidebar) && $sidebar->visible)
    ... render sidebar
@else
    ... don't render sidebar
@endif

Sidebar is visible if at least one of its items is visible. Currently, it can only show facets. Later, there may be more sidebar items:

protected function get_visible(): bool {
    return $this->facets?->visible ?: false;
}

Facets navigation is visible if at least one of the facets is visible:

protected function get_visible(): bool {
    foreach ($this->facets as $facet) {
        if ($facet->visible) {
            return true;
        }
    }

    return false;
}

Finally, the color facet (Facet\Checkboxes) class is visible if the facet counts that it had requested earlier are not empty:

protected function get_visible(): bool {
    return !empty($this->query->result->facets[$this->property->name]);
}

"Drawing" color Facet Template

Finally, a facet view is rendered in the sidebar:

ui::sidebar (Sidebar class)
    ui::facets (Facets class)
        ui::facet.checkboxes (Facet\Checkboxes class)

Let's "draw" the ui::facet.checkboxes template using Tailwind CSS:

{{ $title }}

It's only the first approximation, I'll tune it up later, when it starts showing some data.

color Facet Template Variables

To make it work, let's pass title and options variables. The underlying class, Facet\Checkboxes, does that in its get_data() method.

Here is the first naive version:

protected function get_data(): array {
    return [
        'title' => $this->property->control->title,
        'options' => $this->query->result
            ->facets[$this->property->name]->counts,
    ];
}

To be continued ...