Inside our SPFx web part we have the following code inside the spservices.js code:-

spservices.prototype.getLookupFieldOptions = function (siteUrl, listId, fieldInternalName) {
        return __awaiter(this, void 0, void 0, function () {
            var fieldOptions, web, results, options, _i, options_1, option, error_14;
            return __generator(this, function (_a) {
                switch (_a.label) {
                    case 0:
                        fieldOptions = [];
                        _a.label = 1;
                    case 1:
                        _a.trys.push([1, 5, , 6]);
                        web = new Web(siteUrl);
                        return [4 /*yield*/, web.lists.getById(listId)
                                .filter("InternalName eq '" + fieldInternalName + "'")
                                .select("LookupList", "LookupWebId", "LookupField")
                    case 2:
                        results = _a.sent();
                        if (!results) return [3 /*break*/, 4];
                        return [4 /*yield*/, web.lists.getById(results[0].LookupList)
                                .select("ID", results[0].LookupField)
                    case 3:
                        options = _a.sent();
                        if (options && options.length > 0) {
                            for (_i = 0, options_1 = options; _i < options_1.length; _i++) {
                                option = options_1[_i];
                                    key: option.ID,
                                    text: option[results[0].LookupField]
                        _a.label = 4;
                    case 4: return [3 /*break*/, 6];
                    case 5:
                        error_14 = _a.sent();
                        return [2 /*return*/, Promise.reject(error_14)];
                    case 6: return [2 /*return*/, fieldOptions];

but on runtime the SPFx web part will return this error and it will keep loading forever:-

calendar-web-part_a87ac4ce95dc9057c9f00ccd9727c133.js:1 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'LookupList')

this is the piece of code which is returning the error:-

return [4 /*yield*/, web.lists.getById(results[0].LookupList)

as follow:-

enter image description here

any advice on this please?

  • 2
    Why are you using SPServices in your SPFx web part? Can you post your webpart code where you are actually using SPServices? Dec 10, 2021 at 18:40
  • 2
    What you posted looks like it might be the SPServices source code to me.(?) Unless you are extending SPServices with your own custom function? Are we talking about the same SPServices? Dec 10, 2021 at 19:40
  • 2
    Right, so what I am asking is for you to show the code where your code calls the SPServices function that then leads to the error. Show how your code uses SPServices. Dec 10, 2021 at 20:22
  • 2
    I don't think we're talking about the same SPServices, or if we are, I have never seen SPServices used the way you are using it. SPServices, at least the one that I know, is a jQuery library, which means jQuery has to be loaded to use it. You don't load jQuery in the code you linked to. Also, I have never known SPServices to have a constructor function that takes a SPFx web part context as an argument. Also, some of the functions you are calling, like getLookupFieldOptions and getChoiceFieldOptions I do not see anywhere in the documentation for SPServices. So, sorry, but I can't help. Dec 10, 2021 at 22:27
  • 1
    Can you show us the code you have in spservices file you imported using import spservices from '../../services/spservices';? Dec 14, 2021 at 11:36

1 Answer 1


I believe the problem on that "Select" function, it is trying to read some sort of nested properties in each value.

TypeError: Cannot read properties of undefined (reading 'LookupList') : this error is thrown when the caller is expecting a "Promise" to be returned and instead it is receiving "undefined"

So I assume to replace what you want to return on variables like the following :

var SPListWithFilteredItems = web.lists.getById(listId).fields.usingCaching().filter("InternalName eq '"+ fieldInternalName + "'").select("LookUpList","LookupWebId","LookupField").top(1).get();

return SPListWithFilteredItems;

Try one by one, at first try :





web.lists.getById(listId).fields.usingCaching().filter("InternalName eq '"+ fieldInternalName + "'")

... etc and let me know of the results.


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