SingleDropdownList creates a dropdown list based single select UI component. It is used for filtering results based on the current selection from a list of items.

Example uses:

  • select a category from a list of categories for filtering e-commerce search results.
  • filtering restaurants by a cuisine choice.

Usage

Basic Usage

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<SingleDropdownList componentId="SearchSensor" dataField="brand.raw" />

Usage With All Props

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<SingleDropdownList
	componentId="SearchSensor"
	dataField="brand.raw"
	placeholder="Pick a car"
	defaultSelected="volvo"
	selectAllLabel="All cars"
	sortBy="count"
	showCount
	size={100}
	showFilter={true}
	filterLabel="Car"
	react={{
		and: ['CategoryFilter', 'SearchFilter'],
	}}
/>

Props

  • componentId String unique identifier of the component, can be referenced in other components' react prop.
  • dataField String data field to be connected to the component's UI view. This field is used for doing an aggregation and returns the result. We're using a .raw multifield here. You can use a field of type keyword or not_analyzed depending on your Elasticsearch cluster.
  • defaultSelected string [optional] default selected value pre-selects an option from the list.
  • placeholder String [optional] placeholder to be displayed in the dropdown searchbox. Defaults to "Select a value".
  • size Number [optional] control how many items to display in the List. Defaults to 100.
  • sortBy String [optional] property that decides on how to sort the list items, accepts one of count, asc or desc as valid values. count sorts the list based on the count occurences, with highest value at the top. asc sorts the list in the ascending order of the list item (Alphabetical). desc sorts the list in the descending order of the term. Defaulted to count.
  • showCount Boolean [optional] show count of number of occurences besides an item. Defaults to true.
  • selectAllLabel String [optional] if provided, shows an extra option to select all the options in the list with the provided string value.
  • showFilter Boolean [optional] show as filter when a value is selected in a global selected filters view. Defaults to true.
  • filterLabel String [optional] An optional label to display for the component in the global selected filters view. This is only applicable if showFilter is enabled. Default value used here is componentId.
  • innerProps Object [optional] specifies additional props for the internal components. Accepts an object with the specified keys. Read more about the usage here

Key

Explanation

picker Picker component from native-base
pickerItem Picker.Item component from native-base

Demo


View on Snack

Styles

SingleDropdownList component supports style prop. Read more about it here.

It also supports an innerStyle prop with the following keys:

  • label
  • title

Read more about it here

Extending

SingleDropdownList component can be extended to

  1. customize the look and feel with style,
  2. update the underlying DB query with customQuery,
  3. connect with external interfaces using beforeValueChange, onValueChange and onQueryChange,
  4. specify how search suggestions should be filtered using react prop
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<SingleDropdownList
  ...
  style={{ paddingBottom: 10 }}
  customQuery={
    function(value, props) {
      return {
        match: {
          data_field: "this is a test"
        }
      }
    }
  }
  beforeValueChange={
    function(value) {
      // called before the value is set
      // returns a promise
      return new Promise((resolve, reject) => {
        // update state or component props
        resolve()
        // or reject()
      })
    }
  }
  onValueChange={
    function(value) {
      console.log("current value: ", value)
      // set the state
      // use the value with other js code
    }
  }
  onQueryChange={
    function(prevQuery, nextQuery) {
      // use the query with other js code
      console.log('prevQuery', prevQuery);
      console.log('nextQuery', nextQuery);
    }
  }
  // specify how and which suggestions are filtered using `react` prop.
  react={
    "and": ["pricingFilter", "dateFilter"],
    "or": ["searchFilter"]
  }
/>
  • style Object CSS styles to be applied to the SingleDropdownList component.
  • customQuery Function takes value and props as parameters and returns the data query to be applied to the component, as defined in Elasticsearch Query DSL. Note: customQuery is called on value changes in the SingleDropdownList component as long as the component is a part of react dependency of at least one other component.
  • beforeValueChange Function is a callback function which accepts component's future value as a parameter and returns a promise. It is called everytime before a component's value changes. The promise, if and when resolved, triggers the execution of the component's query and if rejected, kills the query execution. This method can act as a gatekeeper for query execution, since it only executes the query after the provided promise has been resolved.
  • onValueChange Function is a callback function which accepts component's current value as a parameter. It is called everytime the component's value changes. This prop is handy in cases where you want to generate a side-effect on value selection. For example: You want to show a pop-up modal with the valid discount coupon code when a user searches for something in the SingleDropdownList.
  • onQueryChange Function is a callback function which accepts component's prevQuery and nextQuery as parameters. It is called everytime the component's query changes. This prop is handy in cases where you want to generate a side-effect whenever the component's query would change.
  • react Object specify dependent components to reactively update SingleDropdownList's suggestions.
    • key String one of and, or, not defines the combining clause.
      • and clause implies that the results will be filtered by matches from all of the associated component states.
      • or clause implies that the results will be filtered by matches from at least one of the associated component states.
      • not clause implies that the results will be filtered by an inverse match of the associated component states.
    • value String or Array or Object
      • String is used for specifying a single component by its componentId.
      • Array is used for specifying multiple components by their componentId.
      • Object is used for nesting other key clauses.