我有一个返回为json的cookie，但无法获取该值？

Question

I have this cookie

 {"__ngDebug":"true","userdata":"j:{\"id\":10099,\"username\":\"somename@gmail.com\",\"email\":\"somename@gmail.com\",\"role\":\"candidate\"}"}

If I do cookie.userdata I get

"j:{\"id\":10099,\"username\":\"somename@gmail.com\",\"email\":\"somename@gmail.com\",\"role\":\"candidate\"}"

If I do cookie.userdata.j I get nothing. What do I have to do to get email, username, and role?

Answer 1

The Problem

This is because the result of cookie.userdata is a string not an object .

Unfortunately you can not directly parse the result as JSON with JSON.parse , because the value of userdata is not valid JSON (It is object syntax without being wrapped in { and } , and j needs to be wrapped in " )

Best Method: Fix Input At Source

To solve this issue you need to reformat you input string if possible like so,

{"__ngDebug":"true","userdata":{"j":{"id":10099,"username":"somename@gmail.com","email":"somename@gmail.com","role":"candidate"}}}

Note I added { and } to the beginning and end of userdata and I wrapped j in " . Also I made removed the \\ and the " around the value of userdata since we want it to be an object not a string .

Doing this, you should be able to get the value of j like so cookie.userdata.j .

If you for some reason must have j as a string , this will also work,

{"__ngDebug":"true","userdata":"{\"j\":{\"id\":10099,\"username\":\"somename@gmail.com\",\"email\":\"somename@gmail.com\",\"role\":\"candidate\"}}"}

Note I added { and } to the beginning and end of userdata and I wrapped j in "

Then you should be able to get it with JSON.parse(cookie.userdata).j

Not As Good Method: But it works

If you can't fix the input at the source for some reason, you can do some fiddling with the cookie.userdata string to make it valid JSON, then use JSON.parse on it.

Assuming cookie.userdata yields the following,

"j:{\"id\":10099,\"username\":\"somename@gmail.com\",\"email\":\"somename@gmail.com\",\"role\":\"candidate\"}"

Then you can do the following to coerce it into a valid object.

val = cookie.userdata
objVal = JSON.parse('{' + val.replace('j:', '"j":') + '}')
j = objVal.j

What I am doing here is adding the JSON object delimiters { and } and wrapping j in " , which is required by the JSON standard.

Conclusion

Using any of the above methods, once you have j as in object, it is a simple matter to get the username , email , and role .

j.username => "somename@gmail.com"
j.email => "somename@gmail.com"
j.role => "candidate"