Pass parameters to URL in SP.UI.ModalDialog

Question

On load of my site I check if a user is 'registered' with the site (I need specific non-SP data about them which is saved in Users list).

If not, then I show the NewForm.aspx page for Users list.

<script type="text/javascript">
  var siteuri = "/teams/technology-cell-79-new-stores-retail-implementations/testing/testlab";

   function isUserRegistered() {

    var login = _spPageContextInfo.userLoginName;

       $.ajax({
           url: siteuri + "/_api/web/lists/getByTitle('Users')/items?$filter=Title eq '" + login + "'&$select=FirstName,LastName,Email,CellNo,Company,CarReg,AccessCard",
          type: "GET",
          headers: {
            "accept": "application/json;odata=verbose"
          },
       }).success(function (data) {
         var u = data.d.results.length;

         if (u != 1) {
           var options = {
              url: "/teams/technology-cell-79-new-stores-retail-implementations/testing/testlab/Lists/Users/NewForm.aspx?Title='" + login + "'&IsDlg=1",
              width: 800,
              height: 600,
              showClose: true,
              title: "User details"
           };

        SP.SOD.execute('sp.ui.dialog.js', 'SP.UI.ModalDialog.showModalDialog', options);
    }

  }).error(function (er) {
    alert("Error getting user " + er);
  });
}

_spBodyOnLoadFunctionNames.push("isUserRegistered");

</script>

However, I want to pass the information SharePoint does know - that is loginname, email and name (albeit another ajax call to currentUser) - to the dialog and populate the form.

Edited

So, from Leopold's answer - and googling - I added below script between tag in the NewForm.aspx page:

<script type="text/javascript">
  ExecuteOrDelayUntilScriptLoaded(getArgs, "sp.js");

  function getArgs(){
  var args = SP.UI.ModalDialog.get_childDialog().get_args();
}
</script>

But when the dialog is displayed I get this error:

Sorry, something went wrong

An error occurred during the processing of /teams/technology-cell-79-new-stores-retail-implementations/testing/testlab/Lists/Users/NewForm_reg.aspx. Only Content controls are allowed directly in a content page that contains Content controls. 

If I create a new custom form with just HTML and add the script then I get error:

SP is undefined.

Am I missing something simple just to get args for modal dialog?

Answer 1

You can use the args-property in the Options for delivering Parameters into the modal dialog.

Inside the Dialog you can request them using the commonModalDialogGetArguments()function