neo4j access control headers

问题:

i am using neo4j REST api and doing an jquery ajax call This is my first time with REST

i was trying to make a call like this:

$.ajax({
    url: "http://localhost:7474/db/data/cypher",
    accepts: "application/json; charset=UTF-8",
    contentType:"application/json",
    dataType:"json",
    data:{
        "query" : "start n  = node(*) return n",
        "params" : {}
    },
    type:"POSt",
    success:function(data,xhr,status)
    {
        console.log(data);
    },
    error:function(xhr,err,msg){
        console.log(xhr);
        console.log(err);
        console.log(msg);
    }
});

using this i get following error:

XMLHttpRequest cannot load http://localhost:7474/db/data/cypher. 
No 'Access-Control-Allow-Origin' header is present on the requested resource. 
Origin 'http://localhost' is therefore not allowed access.

after this i googled it and got the answer HERE but i dont understand the error so i googled that also but it wasnt of any help so if anyone can tell me what this error means in lucid language and If i remove the contenttype clause wont it create a problem in future

Thanks Alot

回答1:

use:

$.ajax({
            url: "http://localhost:7474/db/data/cypher",
            accepts: "application/json; charset=UTF-8",
            dataType:"json",
            data:{
                "query" : "start n  = node(*) return n",
                "params" : {}
            },
            type:"POST",
            success:function(data,xhr,status)
            {
                console.log(data);
            },
            error:function(xhr,err,msg){
                console.log(xhr);
                console.log(err);
                console.log(msg);
            }
        });

EDIT:

when you post data to server using an ajax call, two requests are created generated from browser, first is OPTIONS(preflight request) and the second is the POST request. If you make an OPTIONS request to your neo4j rest API URL (use fiddler or any other http request maker), you will notice that it DOESNOT contain somwthing like:

Access-Control-Allow-Headers:   content-type

in the response header, which is why when ever you make a post call, whose options doesnot have "Access-Control-Allow-Headers", it will be rejected

Same is explained here