Dojo Javascript: Changing a FilteringSelect SELECT menu when another changes

February 17th, 2009 by Richy B. Leave a reply »

Here’s a bit of Dojo Javascript which will allow you to dynamically change a SELECT sub menu (technically a “FilteringSelect” menu with an id of “secondFilteringSelectId”) when the first SELECT menu is changed (another FilteringSelect menu with an id of “firstFilteringSelectId”). It uses the Dojo’s ItemFileReadStore method to fetch an ajax page (called ajax) before populating the menu. It also has some caching built in to reduce the number of calls to the server and associated network traffic.

dojo.require("dojo.data.ItemFileReadStore");
aSecondFilteringCache=Array();
dojo.addOnLoad(function() {
    dijit.byId('firstFilteringSelectId').onChange=function() {
        fFirstFilteringSelectIdChanged(dijit.byId('firstFilteringSelectId').value);
    }
    fFirstFilteringSelectIdChanged('defaultSetting');
});
function fFirstFilteringSelectIdChanged(thisValue) {
    secondSelect=dijit.byId('secondFilteringSelectId');
    if (aSecondFilteringCache[thisValue]==undefined) {
        var myStore=new dojo.data.ItemFileReadStore({url:'ajax?setting='+thisValue});
        var gotList = function(items, request) {
            aSecondFilteringCache[thisValue]=myStore;
            secondSelect.store=myStore;
            secondSelect.setValue(items[0].id);
        }
        var gotErrors=function(error,request) {
            alert('Request failed:'+error);
        }
        var request=myStore.fetch({onComplete:gotList,onError:gotErrors});
    } else {
        secondSelect.store=aEducationsCached[thisValue];
        secondSelect.setValue(secondSelect.store._arrayOfAllItems[0].id);
    }
}

I am just learning Dojo though, so there could be a much better/sensible way of doing this: let me know if you know/find it!

This post is over 6 months old.

This means that, despite my best intentions, it may no longer be accurate.

This blog holds over 12 years of archived content - during that time, I may have changed my opinion of something, technology will have advanced (and old "best standards" may no longer be the case), my technology "know how" has improved etc etc - it would probably take me a considerable amount of time to update all the archival entries: and defeat the point of keeping them anyway.

Please take these posts for what they are: a brief look into my past, my history, my journey and "caveat emptor".

Comments are closed.

gamy-dance
%d bloggers like this: