In this case, Apollo Client discards any query response data returned by the server and sets the error property in the useQuery result object. The default value is none, which tells Apollo Client to treat all GraphQL errors as runtime errors. You can customize your query error handling by providing the errorPolicyĬonfiguration option to the useQuery hook. To view a complete version of the app we just built, check out the CodeSandbox here. To enable polling for a query, pass a pollInterval configuration option to the useQuery hook with an interval in milliseconds: Polling provides near-real-time synchronization with your server by executing your query periodically at a specified interval. Apollo Client supports two strategies for this: polling and refetching. Sometimes, you want to make sure that your query's cached data is up to date with your server's data. Next, let's learn some techniques for ensuring that our cached data is fresh. You'll notice that the bulldog photo loads instantly the second time around. Then switch to another breed, and then switch back to bulldog. Select bulldog from the dropdown to see its photo appear. In this case, we want to pass the currently selected breed from the dropdown. The variables option is an object that contains all of the variables we want to pass to our GraphQL query. Notice that we're providing a configuration option ( variables) to the useQuery hook this time. DogPhoto accepts a prop called breed that reflects the current value of the dropdown menu in our Dogs component: To see this caching in action, let's build a new component called DogPhoto. This makes later executions of that same query extremely fast. Whenever Apollo Client fetches query results from your server, it automatically caches those results locally. In the next step, we'll associate the dropdown with a more sophisticated query that uses GraphQL variables. When the user selects a dog breed from the populated dropdown, the selection is sent to the parent component via the provided onDogSelected function. The component renders a dropdown menu that's populated with the list of dog breeds returned by the server. When loading is false and there is no error, the query has completed.As long as loading is true (indicating the query is still in flight), the component presents a Loading.Now Open App.js in any code editor and replace the code with the following codeĪpp.As our query executes and the values of loading, error, and data change, the Dogs component can intelligently render different UI elements according to the query's state: Install Dependencies npm install react-native-paper -save npm install react-native-safe-area-context -save npm install react-native-vector-icons -save CocoaPods Installation npx pod-install Code You can also view the Card component provided by react-native-paper, for that, you have to install react-native-paper and react-native-vector-icons dependency. If you want to explore more then you can also see the below example of Card View using react-native-paper React Native Card View using react-native-paper Or on the iOS Simulator by running (macOS only) npx react-native run-ios To run the project on an Android Virtual Device or on real debugging device npx react-native run-android Open a new terminal and run the application. Let Metro Bundler run in its own terminal. Once you start Metro Bundler it will run forever on your terminal until you close it. To start Metro bundler run following command npx react-native start cd ProjectNameįirst, you will need to start Metro, the JavaScript bundler that ships with React Native. Open the terminal again and jump into your project using. import all the components we are going to use Now Open App.js in any code editor and replace the code with the following code App.js // React Native Card View for Android and IOS Please use the following command to install CocoaPods npx pod-install Code Run the following commands npm install -save CocoaPods Installation To install these dependencies open the terminal and jump into your project cd ProjectName To use Card you need to install react-native-elements and dependencies. This will make a project structure with an index file named App.js in your project directory. Try uninstalling the cli and run the cli using npx. Note If the above command is failing, you may have old version of react-native or react-native-cli installed globally on your pc. If you want to start a new project with a specific React Native version, you can use the -version argument: npx react-native init ProjectName -version X.XX.X Npm uninstall -g react-native-cli the following commands to create a new React Native project npx react-native init ProjectName
0 Comments
Leave a Reply. |