How to Create item in SharePoint Online using REST api? If list name contains underscore(_)

Question

I am easily able to create record in other lists using rest API.

But with this one list, api failed. Listname: Project_List Can anyone please help me.

Thanks

Code:

 function GetItemTypeForListName(name){
        return "SP.Data." + name.charAt(0).toUpperCase() + name.split(" ").join("").slice(1) + "ListItem";  
    }
function AddListItem(){
var listName = "Project_List";  
var itemType = GetItemTypeForListName(listName);
            var myID ="";   
            var name = "276 Flinders St";
              
            var item = {  
                "__metadata": { "type": itemType },  
                "Title": name
            };
            $.ajax({  
                url:  _spPageContextInfo.webAbsoluteUrl  + "/_api/web/lists/getbytitle('" + listName + "')/items(" + myID + ")",  
                type: "POST", 
                contentType: "application/json;odata=verbose",  
                data: JSON.stringify(item),  
                headers: {  
                    "Accept": "application/json;odata=verbose",  
                    "X-RequestDigest": $("#__REQUESTDIGEST").val(),  
                    "IF-MATCH": "*",  
                    "X-HTTP-Method":"POST",  
                },  
                success: function (data) {
                    alert("success");  
                },  
                error: function (data) {  
                    alert("failed");  
                }  
            });  
        }

Edit 1: I tried with all solution which you guys gave, but still not working

Error screenshot attached:

Edit 2:

ListItemtype:

Answer 1

As per my understanding you are getting this issue because you are passing wrong type inside __metadata.

Before using the main REST call check the ListItemEntityTypeFullName of your own list and pass it in __metadata property.

You can get this property by hitting below URL in browser tab:

https://<sitecollection>/<site>/_api/web/lists/getbytitle('listName')?$select=ListItemEntityTypeFullName

Do not use the GetItemTypeForListName function in your code. This is kind of a hack which will work correctly only if there are no spaces or special characters in your list name.

Hit above URL in browser tab and pass the ListItemEntityTypeFullName you got from this endpoint in your itemType variable.

Check my answer given in below question:

how to axios post to SharePoint 2013 list

Note:

Generally, _ in list name gets converted into _x005f_ and space in list name gets converted into _x0020_ in ListItemEntityTypeFullName of SharePoint list. But, it is always recommended to use above REST endpoint and check the ListItemEntityTypeFullName of your list.

Answer 2

Is this display name of the list?

Try with %5F var listName = "Project%5FList";

OR

/lists/getbytitle('" + encodeURIComponent(listName) + "')

https://julieturner.net/2016/09/special-characters-in-rest-listitem-metadata/

Answer 3

While you are generating the type using : GetItemTypeForListName in you machine, You should not use like this pattern. You can get the type from the rest end point. The list name with special character like _ will not have the type with proper pattern. Check the type of this list.

Answer 4

Thanks all guys who helped me to solve my issue.

I solved issue by removing quotes from item and previously i was using a variable to store column data and name but now i am directly writing inside ajax.

That's now working successfully, don't know why its not working when i use variable. For further clarification, i added screenshot also.

Answer 5

The reason for the problem is that SharePoint will escape special characters, causing '_ ' to ' x005f '.The title will not affect the excution,but the itemType get by the function GetItemTypeForListName is wrong.

My test code works well:

<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<script>
$(function (){
CreateListItemWithDetails("test")
})
function CreateListItemWithDetails(listName) {
   
    var item = {
        "__metadata": { "type": "SP.Data.Test_x005f_testListItem" },
        "Title": "test"
    };

 

    $.ajax({
        url: _spPageContextInfo.siteAbsoluteUrl + "/_api/web/Lists/getbytitle('test_test')/items",
        type: "POST",
        contentType: "application/json;odata=verbose",
        data: JSON.stringify(item),
        headers: {
            "Accept": "application/json;odata=verbose",
            "X-RequestDigest": $("#__REQUESTDIGEST").val()
        },
        success: function (data) {
            console.log("s");
        },
        error: function (data) {
            console.log(data);
        }
    });
}

</script>

You could update the GetItemTypeForListName,when the itemtype get by GetItemTypeForListName contains '_',we should replace it with ' x005f '.