Hello everybody,
i would like to share a simple way to have the controller reference this available in the callback functions of model crud functions (create, update, remove ...). For javascript experts, the given solution will be logic - for abap'ers starting with javascript, i hope this will be quite helpful.
What do we want?
I wanted to get rid of var that = this; before excuting model operations. In our callback handlers i wanted to use this (controller). We intensivly read about this/that and javascript context and found a better pattern to implement callback handlers. As mentioned for javascript expersts this will be logic.
For quite some time we implemented the success & error callback functions with this pattern:
var that = this;
oModel.create(...., function:{
//Success
that.callMethodSuccess();
}, function : {
//Error
that.callMethodError();
}
The pattern for avoiding that in the callback functions proceed as following:
Define a variable as a function, with the parameters described in the api reference:
var funcOnSucces = function(oData, response) {
//calback code with this
this.callMethodSuccess(); //<- this is the controller reference if the model operation is called with .bind(this)
}
var funcOnError = function(oError) {
this.callMethodError();
}
In the model call use bind() method from javascript:
oModel.create(..., funcOnSuccess.bind(this), funcOnError.bind(this));
I hope this post will help people starting with sapui5 to get the proper controller context into the model callback functions.
As usual feedback & comments are well appreciated.
I wish you all a nice day.
Kind regards,
Michael
Bluesky
