:::{php:namespace} Atk4\Ui
:::

(breadcrumb)=

# Breadcrumb

:::{php:class} Breadcrumb
:::

Implement navigational Breadcrumb, by using https://fomantic-ui.com/collections/breadcrumb.html

## Basic Usage

:::{php:method} addCrumb()
:::

:::{php:method} set()
:::

Here is a simple usage:

```
$crumb = Breadcrumb::addTo($app);
$crumb->addCrumb('User', ['user']);
$crumb->addCrumb('Preferences', ['user_preferences']);
$crumb->set('Change Password');
```

Every time you call addCrumb a new one is added. With set() you can specify the name of the current page.
addCrumb also requires a URL passed as second argument which can be either a string or array (which would then
be passed to url() ({php:meth}`View::url`).

## Changing Divider

:::{php:attr} dividerClass
:::

By default value `right angle icon` is used, but you can change it to `right chevron icon` or simply set to empty string `""`
to use slash.

## Working with Path

:::{php:attr} path
:::

:::{php:method} popTitle()
:::

Calling addCrumb adds more elements into the $path property. Each element there would contain 3 hash values:

- section - name that will appear to the user
- link - where to go if clicked
- divider - which divider to use after the crumb

By default `divider` is set to {php:attr}`Breadcrumb::$dividerClass`. You may also manipulate $path array yourself.
For example the next code will use some logic:

```
$crumb = Breadcrumb::addTo($app);
$crumb->addCrumb('Users', []);

$model = new User($app->db);

$id = $app->stickyGet('user_id');
if ($id) {
    // perhaps we edit individual user?
    $entity = $model->load($id);
    $crumb->addCrumb($entity->get('name'), []);

    // here we can check for additional criteria and display a deeper level on the crumb

    Form::addTo($app)->setEntity($entity);
} else {
    // display list of users
    $table = Table::addTo($app);
    $table->setModel($model);
    $table->addDecorator(['name', [\Atk4\Ui\Table\Column\Link::class, [], ['user_id' => 'id']);
}

$crumb->popTitle();
```