How to add user to SharePoint group using REST & SPServices

Using REST:-

function AddUserToSPGroup()
{
var vCurrentLoggedUser2=$().SPServices.SPGetCurrentUser({fieldName: "UserName",debug: false});

vCurrentLoggedUser2= "KL\\" + vCurrentLoggedUser2;
var requestUri = _spPageContextInfo.webAbsoluteUrl + "/_api/web/sitegroups(57)/users";
$.ajax({
url: requestUri,
type: "POST",
data: JSON.stringify({'__metadata': { 'type': 'SP.User' }, 'LoginName': vCurrentLoggedUser2}),
headers:
{
"accept":"application/json;odata=verbose",
"content-type": "application/json;odata=verbose",
"X-RequestDigest":$("#__REQUESTDIGEST").val()
},
success: onSuccess,
error: onError
});//End of ajax
function onSuccess(data)
{
alert('User Added');
}
function onError(error)
{
alert(JSON.stringify(error));
}
}

Using SPServices:-

function SetContributeAccess()
{
var vCurrentLoggedUser=$().SPServices.SPGetCurrentUser({fieldName: "Title",debug: false});

$().SPServices({
   operation: "AddUserToGroup",
   groupName: "Users",
   userLoginName: vCurrentLoggedUser,
   async: false,
   completefunc: function(data,status){
      alert("User added to group");
   }// End of completefunc
}); //End  of SPServices
}//End of SetContributeAccess

How to get logged user using SPService

var vCurrentLoggedUser2=$().SPServices.SPGetCurrentUser({fieldName: "Title",debug: false});

How to set Managed Metadata field using Jquery

<script src="../../Style Library/spjs-utility.js" type="text/javascript"> </script> 

var vSet = 'abc';

setFieldValue("ManagedMetaDataFieldInternalName",vSet);

</script>

Check out link here to see more on setFieldValue().

How to disable Managed Meta Data field and Browser button

$("div[title='FieldDisplayName1']").prop("disabled",true);//This will disable Managed Metadata textbox.

//Disable Managed Meta Data Browse button
var vNode = $(document.getElementById('FieldInternal_$containercontrolHolder')).prop("disabled",true);
$(vNode ).find("img[title='Browse for a valid choice']").prop("disabled",true);

Hide New and Edit button on Ribbon using JQuery.

Put below CSS file on content editor web part of your page.

<style type="text/css">
#Ribbon\.ListItem\.Manage\.EditProperties-Large
{
   display:none;
}


#Ribbon\.ListItem\.New\.NewListItem-Large
{
  display:none;
}


</style>

Ribbon\.ListItem\.Manage\.EditProperties-Large is the ID of Edit control on Ribbon. Similarly, You can get ID of View and New button as well using Developer tools.

Note: back slash (\) before dot (.) before each class names. Without putting back slash, you wont get the result.