I am porting some javascript code over to typescript and I have come across a problem.
I have an ajax call which passes an object as context, this object contains some callbacks and some other information which are read out by the success or error callbacks which indicate where the success invocation should be redirected to:
function SomeAjaxService
{
var self = this;
self.CheckErrorType = function(...) {
// Do something
};
var SuccessProxyCallback = function(results) {
// Do some stuff with results, like send off some events
this.successCallback(results);
};
var FailureProxyCallback = function(...) {
// Do some stuff with errors, and fire some events
var someErrorType = self.CheckErrorType(...);
this.failureCallback(someErrorType);
};
self.SendRequest = function(requestArgs) {
var ajaxSettings = {
context: requestArgs,
// Assign a load of stuff
};
$.ajax(ajaxSettings);
};
}
Now as you can see the failure proxy calls a local method as well as a using the this context object. So how can you handle this sort of scenario with typescript?
Can you just set self = this in the constructor and continue as you were before?
== EDIT ==
As requested here is a class representation of above showing the issue of this needing to be 2 things due to the missing self variable.
class SomeAjaxService
{
public CheckErrorType(someArg1: any, someArg2: any) {
// Do some stuff with data
};
private SuccessProxyCallback(results: any) {
// Do some stuff with results, like send off some events
this.successCallback(results);
// Does the above *THIS* usage point to the context of the
// Ajax call or the actual instantiated class
};
private FailureProxyCallback(...) {
// Do some stuff with errors, and fire some events
var someErrorType = this.CheckErrorType(...);
// The above *THIS* call cannot be correct if the context has overwritten
// the scope of this, however I dont know if this is true, do I even need
// this.CheckErrorType to invoke a local method?
this.failureCallback(someErrorType);
// As mentioned above same issue here but the *THIS* should hopefully
// point to the context object on the ajax object not the local instance.
};
public SendRequest(requestArgs: any) {
var ajaxSettings : JqueryAjaxSettings = {
context: requestArgs,
// Assign a load of stuff
};
$.ajax(ajaxSettings);
};
}
Like I say above the main issue is that in a method I need to invoke one of the instances methods as well as invoke a method on the context object from the ajax call. With raw javascript I would have self = this and then I can get around this being overridden, which is required to keep the ajax async state object in scope.
