load store with dynamic param - extjs

Question

I want to load a record based on my tree node selection and show it in my form. But my store is not loaded in my controller handler. Where and how should I load the store with my parameter?
var me = this;
var idTag= me.getMyNode();
me.getTagStore().on('beforeload', function(store, operation, eOpts) {
operation.params = {
idTag: idTag
};
}, me);
// it will not be loaded here and I get rec=undefined
var rec = me.getTagStore().load().getAt(0);
me.getMyForm().loadRecord(rec);
And here is my store:
Ext.define('TTT.store.Tag', {
extend: 'Ext.data.Store',
requires: [
'TTT.model.Tag'
],
model: 'TTT.model.Tag',
proxy: {
type: 'ajax',
url: 'tag/find.json',
reader: {
type: 'json',
root: 'data'
}
}
,baseParams: {
idTag: 30
},
});

Answer 1

You can call the load method manually whenever needed and pass any parameters needed, like this:
me.getTagStore().load({
params: {
idTag: idTag
}
});
When you call this you should see your request with the parameter in your console window in the browser.
In your code above, this line:
// it will not be loaded here and I get rec=undefined
var rec = me.getTagStore().load().getAt(0);
The load operation takes a little time, not much but it does take a little time. You need to listen to the load event on your store to be able to do things like this, here is an example:
me.getTagStore().load({
params: {
idTag: idTag
},
scope: this,
callback: function(records, operation, success) {
// the operation object
// contains all of the details of the load operation
console.log(records);
}
});
Checkout the documentation for store.