Skip to main content

Overcoming CORS while testing SPA locally

One of the common problems you common across while developing SPA or hybrid mobile apps locally is that when you make a cross domain API call, this is what you get in your console window


XMLHttpRequest cannot load http://jsonplaceholder.typicode.com/. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8100' is therefore not allowed access. 

The reason for this is the browser security is preventing cross domain Ajax call. You can read more about CORS here.

As a developer you don't want to worry about this and you just want to drink your coffee, write awesome code and test it your machine.

Cool! I do the same!

Here is a little secret. You can tell Chrome to ignore the security and allow cross domain request. To do this, create a new shortcut for Chrome and pass these parameters.
  --disable-web-security --user-Agent="Android" --user-data-dir="c:/temp-chrome-eng"

user-Agent is optional but other two are required to make it work. So your shortcut should look like this

"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --disable-web-security --user-Agent="Android" --user-data-dir="c:/temp-chrome-eng"

Name the short cut as Chrome-X-Domain to make it obvious that you are running under less security. Now click on the shortcut to start the browser. Chrome will warn you that you are using unsupported command line. You can ignore that. Now fire up your application and you can make cross domain api calls.

Please leave a comment or share this post if you found it useful and if it saved you hours scratching your head on how to test cross domain api calls.

Happy programming!


Labels:

Comments

Post a Comment

Popular posts from this blog

How to detect HTML5 support for a browser?

HTML5 has introduced lots of new cool  tags . Not all the browsers support all tags and also the implementation of these tags may be different for each browser. HTML5 specification defines the functional aspects of these tags and not the implementation. Also the general concensus is that by 2022 all browsers will support all new features of HTML5. Of all the modern browsers, Chrome seems to have implemented most, if not all, featutes of HTML5. IE9 supports few. Firefox sits in between. So as a developer how do you make use of the cool HTML5 features without causing any compatibility issues with existing browsers? Traditionally developers have used User Agent to detect browser type and use the features accordingly. However these days, you can easily change a User Agent by using addons in your browser. So you need a more robust way to detect the features supported by the browser as the same engine of two different versions of a browser mig...
Post a Comment
Read more

Searching Unicode characters in Oracle table

Oracle implementation of Regular expression has no support for using hexadecimal code to search for Unicode characters. The only way to search for Unicode character is it use the character itself. Normally with Regular expression, you can use \x or \u followed by hexadecimal code to search for any character. E.g. \x20 will match space. But REGEXP_LIKE in Oracle does not support \x. You need to use unistr function to convert the code to equivalent character and then use it with REGEXP_LIKE. E.g. REGEXP_LIKE(source,'[' ||unistr('\0020')|| ']');
Post a Comment
Read more

System.Configuration in .Net Framework 2 onwards

Often application need custom configuration section. System.Configuration namespace includes classes for reading and writing configuration settings. There is a slight difference in how you use this namespace depending on the Framework version you are using Prior to .Net Framework 2.0, the .Net Framework included System.Configuration namespace, but that version of the namespace is now outdated. If you simply add the System.configuration namespace to your project (using in C#), your application references the outdated namespace. To refer to the updated namespace, follow these steps 1. In VS, open the project that requires System.Configuration namespace. 2. Click on the Project menu and then click Add Reference 3. On the .Net tab, Select System.Configuration as shown in following figure, and click OK 4. Now add the System.Configuration namespace to your project normally using Imports (in VB) or using (in C#) and your application will reference the correct version of the namespa...
Post a Comment
Read more