CODEWITHSUNDEEP
jqueryajaxknockout.js
super cool
super cool

Reputation: 6045

How to restrict subscribe to fire on init for dropdown having a value binded OnLoad?

I do know Subscribe wont fire onload (Init) as per documentation .

But what i have here is bit different and let me try explaining my scenario

I am having a dropdownlist and set of other controls in my create page . Dropdwonlist having a set of listitems when i select something susbscribe will fire (i subscribed dropdown selected value) and inside subscirbe i will do a ajax call and fill the data in remaining controls and i can MODIFY data in other controls which came based on dropdwon selection and finally i will save .

Html:

  <select  data-bind="options:CtList,optionsValue:'Value',optionsText:'Text',optionsCaption:'--Select--',value:CSelected">

Till this point everything works so great but when i take the created id and come to the page i saved before with modifications those are gone and i can see values which are related to dropdwon selection on my page subscribe effect.

View Model Code:

self.CSelected =  ko.observable("");

self.CSelected.subscribe(function (selected) {
if(selected != undefined)
{ //make a ajax call and load vlaues on success  }
});

Truly thats how it tend to happen on OnLoad in this scenario as there is a value for dropdown (i saved dropdown selected value and loading back) .

Any way to restrict the subscribe firing on load if i have a value but it should fire when i change selection . If the same thing can be done using any better approach do enlighten me .

I got this working but i am not satisfied still iam looking for perfect solution using KnockOut .

My code:

var loadcount =0;
self.CSelected.subscribe(function (selected) {
if(selected != undefined) {
if(loadcount >0)
{//make a ajax call and load vlaues on success  }
loadcount++;
}
else
{loadcount++;}
});

Upvotes: 0

Views: 172

Answers (1)

manji
manji

Reputation: 47978

Make the subscribe after filling in the CSelected saved value, not before.

self.CSelected =  ko.observable("");
...
// fill CSelected 
self.CSelected(savedValue);
...
self.CSelected.subscribe(function (selected) {
    if(selected != undefined)
    { //make a ajax call and load vlaues on success  }
});

Upvotes: 1

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