CODEWITHSUNDEEP
javascriptandroidangularjsionic-framework
olajide
olajide

Reputation: 179

Handling CORS Issues in Ionic

I am creating an API with our API server script and am trying to communicate with the API on the IONIC framework application. I am working but it keeps on bringing up the cross-origin blocked error:

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Upvotes: 14

Views: 42345

Answers (6)

Leena
Leena

Reputation: 783

The best solution that worked for me is to use ionic-native http. Follow the link to check its implementation- https://www.freakyjolly.com/ionic-4-native-http-plugin-tutorial-with-example/

Upvotes: 0

Phillip Hartin
Phillip Hartin

Reputation: 889

When developing locally using ionic serve or ionic run/emulate -l -c with livereload enabled, ionic creates a local dev server at port 8100 by default (http://localhost:8100/ ). The origin in this case is localhost:8100 , which when you contact an external service via HTTP with CORS enabled, they deem the request not trustworthy and therefor reject it.

As suggested by Ionic themselves (http://blog.ionic.io/handling-cors-issues-in-ionic/) , you can create a proxy alias within the Ionic app to route the API calls via, avoiding the origin issue altogether, however, their guide was specific for Ionic 1, so here is an update for Ionic v2.

Creating a Proxy in Ionic v2

Open ionic.config.json and add in the following proxies setup. 

{
  "name": "project-name",
  "app_id": "xyz-projectid",
  "v2": true,
  "typescript": true,
  "proxies": [{
    "path": "/api",
    "proxyUrl": "https://the-real-api-host.com"
  }]
}

In this instance, we are creating a path within the ionic app at /api ,which will forward requests to the endpoint https://the-real-api-host.com . If you wanted to use a different api endpoint, for example http://my-custom-api.com/api/v2/ , you could insert it into proxyUrl instead.

Updating References to API Endpoint

In your app code, you now need to update all the references of the base URL for the API endpoint at https://the-real-api-host.com with /api . A call to /api should be detected when in Ionic serve, and proxied to the real address.

Each projects implementation may vary. In my case, I did not have control of the API, as it was an external service, so I could not control the CORS handling/responses myself.

Note: remember to restart the server (ionic serve) or you will get 404's from your API call because it will not yet be proxying.

Upvotes: 24

José Antonio Postigo
José Antonio Postigo

Reputation: 2974

If you have no way to change the server configuration, you should use Http native plugin to perform Http requests from your mobile device, to prevent cors problems. However, in web enviroment you still need to use Angular's HtttClient. Fortunately, with ionic-native-http-connection-backend library you can use the same HttpClient service for both enviroments, and Http native will be used internally if the app is executed from a mobile device. It's a kind of wrapper.

Upvotes: 6

Rajnesh Rathor
Rajnesh Rathor

Reputation: 31

Cors error can only be resolved from server side. But yes for browser only we can resolved it by installing cors extension but for device can be only from server side

Upvotes: 1

Musab
Musab

Reputation: 1127

The issue is just during development phase ,the best way to deal with it is to install "Allow-Control-Allow-Origin" extension in chrome.

Upvotes: 1

Ari
Ari

Reputation: 7556

Creating proxy only works for when you run Ionic on your browser using ionic -serve. CORS issue is still a problem when you run on your device, specially on iOS with WKWebView.

In those cases, you can use Cordova's native HTTP plugin.

See here for details:

https://hackernoon.com/a-practical-solution-for-cors-cross-origin-resource-sharing-issues-in-ionic-3-and-cordova-2112fc282664

Upvotes: 4

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