Select2 change ajax url
I'm working with knockout.js and select2 plugin.
I am trying to change select2 ajax url based on observable value.
for example if based on some choice I make an ajax call to 1 url or other. Here's some sample code:
<input type="hidden" data-bind="combobox: { optionsText: 'Name', optionsValue: 'ID', optionsCaption: '...', sourceUrl: partnerUrl }, value: ApplyToSubject" id="ApplyToSubject" name="ApplyToSubject">
This is how the sourceUrl: partnerUrl is retrieved:
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;
});
I am working with custom binding. Here's the code for it:
// 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');
}
};
It works for a URL that doesn't change, but for URLs that need to be updated, I can't get it to work. (it looks like it saved the first url that was passed to (sourceUrl).
source to share
I finally managed to solve this problem.
From what I could read from the select2 documentation, you must pass a string or function to the ajax url parameter. So this is what I did - I wrote a function that returns the value of the observable (this is the url):
self.returnUrl = function () {
return self.dynamicUrl();
};
And then I pass this function to my binding settings:
<input data-bind="combobox: { ... sourceUrl: $data.returnUrl }, value: ApplyToSubject" type="hidden" >
Then the custom binding works the same way as in the code in the question, with a slight change:
...
ajax: {
url: sourceUrl <- this is the returnUrl function
...
}
source to share