SingleDropdownList

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.

Note

This component is exactly like the SingleList component except the UI is based on a dropdown, ideal for showing additional UI filters while conserving screen space.

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

<template>
    <single-dropdown-list
        componentId="CitySensor"
        dataField="group.group_city.raw"
        title="Cities"
    />
</template>

Usage With All Props

<single-dropdown-list
  componentId="CitySensor"
  dataField="group.group_city.raw"
  title="Cities"
  sortBy="count"
  defaultSelected="London"
  placeholder="Search City"
  selectAllLabel="All Cities"
  filterLabel="City"
  :showCount="true"
  :react="{ and: ['CategoryFilter', 'SearchFilter'] }"
  :size="100"
  :showFilter="true"
  :URLParams="false"
/>

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.
• nestedField String [optional]
  use to set the nested mapping field that allows arrays of objects to be indexed in a way that they can be queried independently of each other. Applicable only when dataField is a part of nested type.
• title String or JSX [optional]
  title of the component to be shown in the UI.
• 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.
• defaultSelected string [optional]
  default selected value pre-selects an option from the list.
• showCount Boolean [optional]
  show count of number of occurences besides an item. Defaults to true.
• showSearch Boolean [optional]
  whether to show a searchbox to filter the list items locally. Defaults to false.

• renderItem Function|scoped-slot [optional]
  customize the rendered list via a function or scoped-slot which receives the item label, count and isChecked & expects a JSX or String back. For example:

  renderItem={({ label, count }) => (
      <div>
          {label}
          <span style={{ marginLeft: 5, color: 'dodgerblue' }}>
              {count}
          </span>
      </div>
  )}
  

  or

    <template slot="renderItem" scoped-slot="{ label, count }">
        <div>
            {{label}}
            <span :style="{ marginLeft: 5, color: 'dodgerblue' }">
                {{count}}
            </span>
        </div>
    </template>

• renderError String|Function|scoped-slot [optional] can be used to render an error message in case of any error.

    renderError={error => (
            <div>
                Something went wrong!<br/>Error details<br/>{error}
            </div>
        )
    }

or

   <template slot="renderError" scoped-slot="error">
        <div>
            Something went wrong!<br/>Error details<br/>{{ error }}
        </div>
    </template>

• showMissing Boolean [optional]
  defaults to false. When set to true it also retrives the aggregations for missing fields under the label specified by missingLabel.
• missingLabel String [optional]
  defaults to N/A. Specify a custom label to show when showMissing is set to true.
• placeholder String [optional]
  placeholder to be displayed in the dropdown searchbox.
• 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.
• URLParams Boolean [optional]
  enable creating a URL query string parameter based on the selected value of the list. This is useful for sharing URLs with the component state. Defaults to false.
• showLoadMore Boolean [optional]
  defaults to false and works only with elasticsearch >= 6 since it uses composite aggregations. This adds a “Load More” button to load the aggs on demand combined with the size prop. Composite aggregations are in beta and this is an experimental API which might change in a future release.

Demo

Styles

SingleDropdownList component supports innerClass prop with the following keys:

• title
• select
• list
• icon
• count

Read more about it here.

Extending

SingleDropdownList component can be extended to

1. customize the look and feel with className,
2. update the underlying DB query with customQuery,
3. connect with external interfaces using beforeValueChange, valueChange and queryChange,
4. specify how options should be filtered or updated using react prop.

<single-dropdown-list
  ...
  className="custom-class"
  :customQuery=`
    function(value, props) {
      return {
        query: {
            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()
      })
    }`
    @valueChange=`
        function(value) {
        console.log("current value: ", value)
        // set the state
        // use the value with other js code
    }`
    @queryChange=`
        function(prevQuery, nextQuery) {
        // use the query with other js code
        console.log('prevQuery', prevQuery);
        console.log('nextQuery', nextQuery);
        }`
    // specify how and which options are filtered using `react` prop.
    :react=`{
        "and": ["pricingFilter", "dateFilter"],
        "or": ["searchFilter"]
    }`
/>

• className String
  CSS class to be injected on the component container.
• 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.
• defaultQuery Function takes value and props as parameters and returns the data query to be applied to the source component, as defined in Elasticsearch Query DSL. Note: defaultQuery doesn’t get leaked to other components.
• 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.
• transformData Function [optional]
  allows transforming the data to render inside the list. You can change the order, remove, or add items, tranform their values with this method. It provides the data as param which is an array of objects of shape { key: <string>, doc_count: <number> } and expects you to return the array of objects of same shape.

• react Object
  specify dependent components to reactively update SingleDropdownList’s options.

  • 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.

Events

• queryChange
  is an event which accepts component’s prevQuery and nextQuery as parameters. It is called everytime the component’s query changes. This event is handy in cases where you want to generate a side-effect whenever the component’s query would change.

• valueChange
  is an event which accepts component’s current value as a parameter. It is called everytime the component’s value changes. This event 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 list item is selected in a “Discounted Price” SingleList.

• error gets triggered in case of an error and provides the error object, which can be used for debugging or giving feedback to the user if needed.