How to access a custom field of a list using REST

Question

I'm trying to get information from a list in a custom SPField called "My Field" with the internal name "MyField" using this JavaScript code:

$.ajax({
    url: "http://<URL>/_api/web/lists/GetByTitle('Documents')/items?$select=MyField",
    type: "GET",
    headers: {
        "accept": "application/json;odata=verbose",
    },
    success: function(data){
        $.each(data.d.results, function (key, value) {
            console.log(value.MyField);
        });
    },
    error: function(error){
        console.warn(JSON.stringify(error));
    }
});

MyField has a custom field value type.

I found this description

Not all types of column are available via REST, most annoyingly managed metadata columns are amongst this group of unsupported column types. Further, not all types of column will return data for an entry just by including them in the $select parameter, an example of which is Lookup (single or multi-value) columns. ...

Is this still the case, and what do I have to implement in the custom SPField, to make it retrievable via REST ...

Any ideas what I'm doing wrong?

Answer 1

If my field is Taxonomy Column, I would take a look at this blog.

It explains how to retrive Taxonomy columns with REST.

Basically you need to do a Post to a different endpoint:

$.ajax({
    url: "http://sharepointificate/_api/web/Lists/GetByTitle('Documents')/GetItems(query=@v1)?@v1={'ViewXml':'<View><Query></Query></View>'}",
    type: "POST",

Answer 2

The below code gives the results of the field into a variable called myfield.

<script type="text/javascript">
SP.SOD.executeFunc('sp.js','SP.ClientContext',update);
var returnedItems;
function update(){

var context=new SP.ClientContext();
var list=context.get_web().get_lists().getByTitle('Documents');

var caml = new SP.CamlQuery();
caml.set_viewXml("<View><Query></Query></View>");
returnedItems=list.getItems(caml);
context.load(returnedItems);
context.executeQueryAsync(onSucceededCallback,onFailedCallback);

}

function onSucceededCallback(sender,args){
alert();
var enumerator = returnedItems.getEnumerator(); 

while(enumerator.moveNext()){
var listItem=enumerator.get_current();
var myfield=listItem.get_item('MyField');

}
    }

function onFailedCallback(sender,args){
alert("Failed to connect:  "+args.get_message());
}
</script>

You can access the variable in javascript and use it anywhere from JS

Answer 3

Can you try

dataType: "json",

after

type: "GET",