Question

我正在使用knockout.js和select2插件我试图根据一个可观察的值来改变select2 ajax url 例如，如果基于某些选择，我执行ajax调用1 url或另一个。以下是示例代码：

<input type="hidden" data-bind="combobox: { optionsText: 'Name', optionsValue: 'ID', optionsCaption: 'Избери...', sourceUrl: partnerUrl }, value: ApplyToSubject" id="ApplyToSubject" name="ApplyToSubject">

这是检索sourceUrl：partnerUrl的方式：

self.partnerUrl = ko.computed(function () {
        var value = "";
        if (something)
        {
            value = apiUrls.customer;
        }
        else if (something else)
        {
            value = apiUrls.vendor;
        }
        else if(or another thing)
        {
            value = apiUrls.employee;
        }
        return value;
    });

我使用自定义绑定。这是代码：

// documentation http://ivaynberg.github.io/select2/
ko.bindingHandlers.combobox = {
    init: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
        var obj = valueAccessor(),
            allBindings = allBindingsAccessor();
        var optionsText = ko.utils.unwrapObservable(obj.optionsText);
        var optionsValue = ko.utils.unwrapObservable(obj.optionsValue);
        var sourceUrl = ko.utils.unwrapObservable(obj.sourceUrl);
        var selectedID = ko.utils.unwrapObservable(allBindings.value);
        var model = obj.model;
        var unwrapped = ko.utils.unwrapObservable(obj.model);

        $(element).select2({
            minimumInputLength: 3,
            formatResult: function formatResult(result) {
                return result.text;
            },
            data: function (model) {
                return { id: unwrapped[optionsValue](), text: unwrapped[optionsText](), data: unwrapped }
            },
            initSelection: function (element, callback) {
                if (unwrapped && selectedID !== "") {
                    callback({ id: unwrapped[optionsValue](), text: unwrapped[optionsText](), data: unwrapped });
                }
            },
            ajax: {
                quietMillis: 500,
                url: subdirUrl + sourceUrl,
                dataType: 'json',
                data: function (search, page) {
                    return {
                        page: page,
                        search: search
                    };
                },
                results: function (data) {
                    var result = [];
                    $.each(data.list, function (key, value) {
                        result.push({ id: value[optionsValue], text: value[optionsText], data: value });
                    });
                    var more = data.paging.currentPage < data.paging.pageCount;
                    return { results: result, more: more };
                }
            }
        });
        $(element).on('select2-selected', function (eventData) {
            if (eventData.choice) {
                // item selected
                var selectedItem = eventData.choice.data;
                var selectedId = eventData.choice.id;
                model(selectedItem);
            }
            else {
                model(undefined);
            }
        });

        ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
            $(element).select2('destroy');
        });
    },
    update: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
        var obj = valueAccessor(),
            allBindings = allBindingsAccessor();
        var selectedID = ko.utils.unwrapObservable(allBindings.value);
        $(element).val(selectedID).trigger('change');
    }
};

它适用于不会更改的网址，但对于需要更新的网址，我无法使其正常工作。（看起来它保留了传递的第一个URL（sourceUrl）。

Answer 1

我终于设法解决了这个问题。

从我从select2文档中读到的内容，你应该将字符串或函数传递给ajax url参数。所以这就是我所做的我编写了一个返回observable值（即url）的函数：

self.returnUrl = function () {
    return self.dynamicUrl();
};

然后我将该函数传递给我的自定义绑定选项：

<input data-bind="combobox: { ... sourceUrl: $data.returnUrl }, value: ApplyToSubject" type="hidden" >

然后自定义绑定的工作方式与问题中的代码相同，只需稍加改动：

...
ajax: {
     url: sourceUrl <- this is the returnUrl function
...
}

select2更改ajax网址

1 个答案: