I've run into an issue while trying to build a page that allows the user to click on a word and get its definition in a bootstrap popover. That is achieved by sending an API request and updating the state with the received data.
The problem is that the popover only appears after the second click on the word. The console.log() in useEffect() shows that every time a new word is clicked an API request is made. For the popover to appear the same word must be clicked twice. It'd be better if it only took one click.
import React, { useState, useRef, useEffect } from "react";
import axios from "axios";
import { Alert, Popover, OverlayTrigger } from "react-bootstrap";
export default function App() {
const [text, setText] = useState(
"He looked at her and saw her eyes luminous with pity."
);
const [selectedWord, setSelectedWord] = useState("luminous");
const [apiData, setApiData] = useState([
{
word: "",
phonetics: [{ text: "" }],
meanings: [{ definitions: [{ definition: "", example: "" }] }]
}
]);
const words = text.split(/ /g);
useEffect(() => {
var url = "https://api.dictionaryapi.dev/api/v2/entries/en/" + selectedWord;
axios
.get(url)
.then(response => {
setApiData(response.data)
console.log("api call")
})
.catch(function (error) {
if (error) {
console.log("Error", error.message);
}
});
}, [selectedWord]);
function clickCallback(w) {
var word = w.split(/[.!?,]/g)[0];
setSelectedWord(word);
}
const popover = (
<Popover id="popover-basic">
<Popover.Body>
<h1>{apiData[0].word}</h1>
<h6>{apiData[0].meanings[0].definitions[0].definition}</h6>
</Popover.Body>
</Popover>
);
return (
<Alert>
{words.map((w) => (
<OverlayTrigger
key={uuid()}
trigger="click"
placement="bottom"
overlay={popover}
>
<span onClick={() => clickCallback(w)}> {w}</span>
</OverlayTrigger>
))}
</Alert>
);
}
UPDATE:
Changed the apiData initialization and the <Popover.Body> component. That hasn't fixed the problem.
const [apiData, setApiData] = useState(null)
<Popover.Body>
{
apiData ?
<div>
<h1>{apiData[0].word}</h1>
<h6>{apiData[0].meanings[0].definitions[0].definition}</h6>
</div> :
<div>Loading...</div>
}
</Popover.Body>
Here's what I think is happening:
setApiData(data).setSelectedWord("pity") causes the component to start rerendering.setApiData(data).Selecting another word will repeat this process over and over.
To fix this, you need to first make use of the show property to show the popover after rendering it out if it matches the selected word. But what if the word appears multiple times? If you did this for the word "her", it would show the popover in multiple places. So instead of comparing against each word, you'd have to assign each word a unique ID and compare against that.
To assign words an ID that won't change between renders, we need to assign them IDs at the top of your component and store them in an array. To make this "simpler", we can abstract that logic into a re-useable function outside of your component:
// Use this function snippet in demos only, use a more robust package
// https://gist.github.com/jed/982883 [DWTFYWTPL]
const uuid = function b(a){return a?(a^Math.random()*16>>a/4).toString(16):([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g,b)}
// Splits the text argument into words, removes excess formatting characters and assigns each word a UUID.
// Returns an array with the shape: { [index: number]: { word: string, original: string, uuid: string }, text: string }
function identifyWords(text) {
// split input text into words with unique Ids
const words = text
.split(/ +/)
.map(word => {
const cleanedWord = word
.replace(/^["]+/, "") // remove leading punctuation
.replace(/[.,!?"]+$/, "") // remove trailing punctuation
return { word: cleanedWord, original: word, uuid: uuid() }
});
// attach the source text to the array of words
// we can use this to prevent unnecessary rerenders
words.text = text;
// return the array-object
return words;
}
Within the component, we need to setup the state variables to hold the words array. By passing a callback to useState, React will only execute it on the first render and skip calling it on rerenders.
// set up state array of words that have their own UUIDs
// note: we don't want to call _setWords directly
const [words, _setWords] = useState(() => identifyWords("He looked at her and saw her eyes luminous with pity."));
Now that we have words and _setWords, we can pull out the text value from it:
// extract text from words array for convenience
// probably not needed
const text = words.text;
Next, we can create our own setText callback. This could be simpler, but I wanted to make sure we support React's mutating update syntax (setText(oldValue => newValue)):
// mimic a setText callback that actually updates words as needed
const setText = (newTextOrCallback) => {
if (typeof newTextOrCallback === "function") {
// React mutating callback mode
_setWords((words) => {
const newText = newTextOrCallback(words.text);
return newText === words.text
? words // unchanged
: identifyWords(newText); // new value
});
} else {
// New value mode
return newTextOrCallback === words.text
? words // unchanged
: identifyWords(newTextOrCallback); // new value
}
}
Next, we need to set up the currently selected word. Once the definition is available, this word's popover will be shown.
const [selectedWordObj, setSelectedWordObj] = useState(() => words.find(({word}) => word === "luminous"));
If you don't want to show a word by default, use:
const [selectedWordObj, setSelectedWordObj] = useState(); // nothing selected by default
To fix the API call, we need to make use of the "use async effect" pattern (there are libraries out there to simplify this):
const [apiData, setApiData] = useState({ status: "loading" });
useEffect(() => {
if (!selectedWordObj) return; // do nothing.
// TODO: check cache here
// clear out the previous definition
setApiData({ status: "loading" });
let unsubscribed = false;
axios
.get(`https://api.dictionaryapi.dev/api/v2/entries/en/${selectedWordObj.word}`)
.then(response => {
if (unsubscribed) return; // do nothing. out of date response
const body = response.data;
// unwrap relevant bits
setApiData({
status: "completed",
word: body.word,
definition: body.meanings[0].definitions[0].definition
});
})
.catch(error => {
if (unsubscribed) return; // do nothing. out of date response
console.error("Failed to get definition: ", error);
setApiData({
status: "error",
word: selectedWordObj.word,
error
});
});
return () => unsubscribed = true;
}, [selectedWord]);
The above code block makes sure to prevent calling the setApiData methods when they aren't needed any more. It also uses a status property to track it's progress so you can render the result properly.
Now to define a popover that shows a loading message:
const loadingPopover = (
<Popover id="popover-basic">
<Popover.Body>
<span>Loading...</span>
</Popover.Body>
</Popover>
);
We can mix that loading popover with apiData to get a popover to show the definition. If we're still loading the definition, use the loading one. If we've had an error, show the error. If it completed properly, render out the defintion. To make this easier, we can put this logic in a function outside of your component like so:
function getPopover(apiData, loadingPopover) {
switch (apiData.status) {
case "loading":
return loadingPopover;
case "error":
return (
<Popover id="popover-basic">
<Popover.Body>
<h1>{apiData.word}</h1>
<h6>Couldn't find definition for {apiData.word}: {apiData.error.message}</h6>
</Popover.Body>
</Popover>
);
case "completed":
return (
<Popover id="popover-basic">
<Popover.Body>
<h1>{apiData.word}</h1>
<h6>{apiData.definition}</h6>
</Popover.Body>
</Popover>
);
}
}
We call this funtion in the component using:
const selectedWordPopover = getPopover(apiData, loadingPopover);
Finally, we render out the words. Because we are rendering out an array, we need to use a key property that we'll set to each word's Id. We also need to select the word that was clicked - even if there were more than one of the same words, we only want just the clicked one. For that we'll check its Id too. If we click on a particular word, we need to sure that the one we clicked on is selected. We also need to render out the original word with its punctuation. This is all done in this block:
return (
<Alert>
{words.map((wordObj) => {
const isSelectedWord = selectedWordObj && selectedWordObj.uuid = wordObj.uuid;
return (
<OverlayTrigger
key={wordObj.uuid}
show={isSelectedWord}
trigger="click"
placement="bottom"
overlay={isSelectedWord ? selectedWordPopover : loadingPopover}
>
<span onClick={() => setSelectedWordObj(wordObj)}> {wordObj.original}</span>
</OverlayTrigger>
)})}
</Alert>
);
Bringing all that together gives:
import React, { useState, useRef, useEffect } from "react";
import axios from "axios";
import { Alert, Popover, OverlayTrigger } from "react-bootstrap";
// Use this function snippet in demos only, use a more robust package
// https://gist.github.com/jed/982883 [DWTFYWTPL]
const uuid = function b(a){return a?(a^Math.random()*16>>a/4).toString(16):([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g,b)}
// Splits the text argument into words, removes excess formatting characters and assigns each word a UUID.
// Returns an array with the shape: { [index: number]: { word: string, original: string, uuid: string }, text: string }
function identifyWords(text) {
// split input text into words with unique Ids
const words = text
.split(/ +/)
.map(word => {
const cleanedWord = word
.replace(/^["]+/, "") // remove leading characters
.replace(/[.,!?"]+$/, "") // remove trailing characters
return { word: cleanedWord, original: word, uuid: uuid() }
});
// attach the source text to the array of words
words.text = text;
// return the array
return words;
}
function getPopover(apiData, loadingPopover) {
switch (apiData.status) {
case "loading":
return loadingPopover;
case "error":
return (
<Popover id="popover-basic">
<Popover.Body>
<h1>{apiData.word}</h1>
<h6>Couldn't find definition for {apiData.word}: {apiData.error.message}</h6>
</Popover.Body>
</Popover>
);
case "completed":
return (
<Popover id="popover-basic">
<Popover.Body>
<h1>{apiData.word}</h1>
<h6>{apiData.definition}</h6>
</Popover.Body>
</Popover>
);
}
}
export default function App() {
// set up state array of words that have their own UUIDs
// note: don't call _setWords directly
const [words, _setWords] = useState(() => identifyWords("He looked at her and saw her eyes luminous with pity."));
// extract text from words array for convenience
const text = words.text;
// mimic a setText callback that actually updates words as needed
const setText = (newTextOrCallback) => {
if (typeof newTextOrCallback === "function") {
// React mutating callback mode
_setWords((words) => {
const newText = newTextOrCallback(words.text);
return newText === words.text
? words // unchanged
: identifyWords(newText); // new value
});
} else {
// New value mode
return newTextOrCallback === words.text
? words // unchanged
: identifyWords(newTextOrCallback); // new value
}
}
const [selectedWordObj, setSelectedWordObj] = useState(() => words.find(({word}) => word === "luminous"));
const [apiData, setApiData] = useState({ status: "loading" });
useEffect(() => {
if (!selectedWordObj) return; // do nothing.
// TODO: check cache here
// clear out the previous definition
setApiData({ status: "loading" });
let unsubscribed = false;
axios
.get(`https://api.dictionaryapi.dev/api/v2/entries/en/${selectedWordObj.word}`)
.then(response => {
if (unsubscribed) return; // do nothing. out of date response
const body = response.data;
// unwrap relevant bits
setApiData({
status: "completed",
word: body.word,
definition: body.meanings[0].definitions[0].definition
});
})
.catch(error => {
if (unsubscribed) return; // do nothing. out of date response
console.error("Failed to get definition: ", error);
setApiData({
status: "error",
word: selectedWordObj.word,
error
});
});
return () => unsubscribed = true;
}, [selectedWord]);
function clickCallback(w) {
var word = w.split(/[.!?,]/g)[0];
setSelectedWord(word);
}
const loadingPopover = (
<Popover id="popover-basic">
<Popover.Body>
<span>Loading...</span>
</Popover.Body>
</Popover>
);
const selectedWordPopover = getPopover(apiData, loadingPopover);
return (
<Alert>
{words.map((wordObj) => {
const isSelectedWord = selectedWordObj && selectedWordObj.uuid = wordObj.uuid;
return (
<OverlayTrigger
key={wordObj.uuid}
show={isSelectedWord}
trigger="click"
placement="bottom"
overlay={isSelectedWord ? selectedWordPopover : loadingPopover}
>
<span onClick={() => setSelectedWordObj(wordObj)}> {wordObj.original}</span>
</OverlayTrigger>
)})}
</Alert>
);
}
Note: You can improve this by caching the results from the API call.