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Part 10c: Environment variables now supported #3500

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Part 10c: Environment variables now supported #3500

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2 changes: 1 addition & 1 deletion src/content/10/en/part10c.md
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Expand Up @@ -333,7 +333,7 @@ The changes in the <em>useRepositories</em> hook should not affect the <em>Repos

Every application will most likely run in more than one environment. Two obvious candidates for these environments are the development environment and the production environment. Out of these two, the development environment is the one we are running the application right now. Different environments usually have different dependencies, for example, the server we are developing locally might use a local database whereas the server that is deployed to the production environment uses the production database. To make the code environment independent we need to parametrize these dependencies. At the moment we are using one very environment dependant hardcoded value in our application: the URL of the server.

We have previously learned that we can provide running programs with environment variables. These variables can be defined in the command line or using environment configuration files such as <i>.env</i> files and third-party libraries such as <i>Dotenv</i>. Unfortunately, React Native doesn't have direct support for environment variables. However, we can access the Expo configuration defined in the <i>app.json</i> file at runtime from our JavaScript code. This configuration can be used to define and access environment dependant variables.
We have previously learned that we can provide running programs with environment variables. These variables can be defined in the command line or using environment configuration files such as <i>.env</i> files and third-party libraries such as <i>Dotenv</i>. <s>Unfortunately, React Native doesn't have direct support for environment variables.<s> However, we can access the Expo configuration defined in the <i>app.json</i> file at runtime from our JavaScript code. This configuration can be used to define and access environment dependant variables.

The configuration can be accessed by importing the <em>Constants</em> constant from the <i>expo-constants</i> module as we have done a few times before. Once imported, the <em>Constants.expoConfig</em> property will contain the configuration. Let's try this by logging <em>Constants.expoConfig</em> in the <em>App</em> component:

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