2020-09-24-prevent-filter-combination-with-no-result.md

title	issue
Prevent filter combinations with no result	NEXT-5993

Core

• Added possibility to differentiate between install and update process in a migration

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Storefront

• Added possibility for filter plugins to disable themselves when filter combinations are not available
• Added widgets.search.filter route to SearchController
• Added parameter event to private method _onChangeRating in the filter-rating.plugin.js plugin

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Upgrade Information

Support of disabled filters feature

If your custom filter should support the new feature you need to create a refreshDisabledState() function. This plugin gets two parameters:

• filters: Result of the widgets.search.filter request
• filterParams: Actual filter parameters of the page

These parameters can be used to refresh the state of the filter plugin. Here is a small example for a boolean filter:

refreshDisabledState(filter) {
        let value = 0;

        const booleanFilter = filter[this.options.name];

        if (booleanFilter.max) {
            value = booleanFilter.max;
        }

        if(value > 0) {
            this.el.classList.remove('disabled');
            this.checkbox.removeAttribute('disabled');
        } else {
            this.el.classList.add('disabled');
            this.checkbox.disabled = true;
        }
    }