DataQuery Component

A thin wrapper around the useDataQuery hook

Basic Usage

import { DataQuery } from '@dhis2/app-runtime'

// within a React component's JSX render tree
return (
    <DataQuery query={query}>
        {({ loading, error, data, refetch }) => {
            /* child render funtion */
        }}
    </DataQuery>
)

Input Props

Name	Type	Required	Description
query	Query	required	The Query definition describing the requested data
variables	Object		Variables to be passed to the dynamic portions of the query
onComplete	Function		Callback function to be called on successfull completion of the query. Called with the response data as the only argument.
onError	Function		Callback function to be called on failure of the query. Called with the error instance as the only argument.
lazy	boolean		If true, wait until refetch is called before fetching data. Default: false

Render Function Props

Name	Type	Description
called	boolean	true if the data request has been initiated with either lazy: false or refetch() at least once
loading	boolean	true if the data is not yet available and no error has yet been encountered
error	Error or undefined	undefined if no error has occurred, otherwise the Error which was thrown
data	QueryResult or undefined	undefined if the data is loading or an error has occurred, otherwise a map from the name of each QueryDefinition defined in the Query to the resulting data for that query
refetch	Function	This function can be called to refetch the data. Any in-flight HTTP requests will automatically be aborted.
engine	Data Engine	A reference to the DataEngine instance

Example

import React from 'react'
import { DataQuery } from '@dhis2/app-runtime'

const query = {
    indicators: {
        resource: 'indicators',
        params: ({ count }) => ({
            order: 'shortName:desc',
            pageSize: count,
        })
    },
}
export const IndicatorList = ({ count }) => (
    <DataQuery query={query} variables={{ count }}>
        {({ loading, error, data }) => (
            <h3>Indicators (first {count})</h3>
            {loading && <span>...</span>}
            {error && <span>{`ERROR: ${error.message}`}</span>}
            {data && (
                <pre>
                    {data.indicators.indicators
                        .map(ind => ind.displayName)
                        .join('\n')}
                </pre>
            )}
        )}
    </DataQuery>
)