Posted on May 1, 2024 • Originally published at Medium

Import and Export locations on Google Maps

#webdev #javascript #beginners #react

Hello readers!

Previously I wrote about adding a click function on Google Maps and displaying markers.

Today I want to add another feature in the app by allowing import and export locations.

Create Import and Export Buttons

I added import and export location buttons to the bottom of the web page like this.

{/* displays export and import options */} <div className="list-footer"> <AppButton handleClick={exportLocations}> Export Locations </AppButton>  <input className="app-button" type="file" accept=".json" onChange={importLocations} />  </div>

Import Locations Logic

This function imports a location list from a JSON file, parses the data, and appends it to the existing list of locations. It utilizes a FileReader to read the file contents and updates the state accordingly.

// Function to import location list from JSON const importLocations = (event) => { const file = event.target.files[0]; const reader = new FileReader(); reader.onload = (e) => { const importedData = JSON.parse(e.target.result); setListOfLocations([...listOfLocations, ...importedData]); }; reader.readAsText(file); };

Export Locations Logic

This function exports the location list as a JSON file by converting the list of locations to JSON format, creating a Blob with the JSON data, and generating a download link for the user to save the file.
Finally, it initiates the download of the JSON file and removes the dynamically created download link from the document.

// Function to export location list as JSON const exportLocations = () => { const data = JSON.stringify(listOfLocations); const blob = new Blob([data], { type: "application/json" }); const url = URL.createObjectURL(blob); const a = document.createElement("a"); a.href = url; a.download = "locations.json"; document.body.appendChild(a); a.click(); document.body.removeChild(a); };