component's onchange event not triggered - ractivejs

I'm guessing that this might be intentional but couldn't find mention in the docs. (If it's intentional, I'll make a PR to clarify the docs).
ref: this jsfiddle
my html:
<div id='container'/>
and my javascript:
Person = Ractive.extend({
template : '<p>{{name}}</p>',
onchange : function(obj){console.log(obj)}
})
flintstones = new Ractive({
el : '#container',
template : "{{#names}}<person/>{{/}}",
data : {names : [{id:1, name:"Fred"},{id: 2, name:"Barney"}]},
components : {person : Person}
})
if I make a data change in the component with:
flintstones.findAllComponents('person')[1].set('name','Wilma')
there is no 'onchange' event logged to the console. However if the flintstones Ractive instance is configured with an 'onchange' handler, then setting the data in the component is logged.
Intentional or bug or am I doing something wrong here?

The onchange event is only fired for data owned (introduced by) the component instance.
Use this.observe(...) the be notified about changes to any data used within the component regardless of where the data originated.

Related

How to Attach Events to Table Checkboxes in Material Design Lite

When you create a MDL table, one of the options is to apply the class 'mdl-data-table--selectable'. When MDL renders the table an extra column is inserted to the left of your specified columns which contains checkboxes which allow you to select specific rows for actions. For my application, I need to be able to process some JavaScript when a person checks or unchecks a box. So far I have been unable to do this.
The problem is that you don't directly specify the checkbox controls, they are inserted when MDL upgrades the entire table. With other MDL components, for instance a button, I can put an onclick event on the button itself as I'm specifying it with an HTML button tag.
Attempts to put the onclick on the various container objects and spans created to render the checkboxes has been unsuccessful. The events I attach don't seem to fire. The closest I've come is attaching events to the TR and then iterating through the checkboxes to assess their state.
Here's the markup generated by MDL for a single checkbox cell:
<td>
<label class="mdl-checkbox mdl-js-checkbox mdl-js-ripple-effect mdl-data-table__select mdl-js-ripple-effect--ignore-events is-upgraded" data-upgraded=",MaterialCheckbox">
<input type="checkbox" class="mdl-checkbox__input">
<span class="mdl-checkbox__focus-helper"></span>
<span class="mdl-checkbox__box-outline">
<span class="mdl-checkbox__tick-outline"></span>
</span>
<span class="mdl-checkbox__ripple-container mdl-js-ripple-effect mdl-ripple--center">
<span class="mdl-ripple"></span>
</span>
</label>
</td>
None of this markup was specified by me, thus I can't simply add an onclick attribute to a tag.
If there an event chain I can hook into? I want to do it the way the coders intended.
It's not the nicest piece of code, but then again, MDL is not the nicest library out there. Actually, it's pretty ugly.
That aside, about my code now: the code will bind on a click event on document root that originated from an element with class mdl-checkbox.
The first problem: the event triggers twice. For that I used a piece of code from Underscore.js / David Walsh that will debounce the function call on click (if the function executes more than once in a 250ms interval, it will only be called once).
The second problem: the click events happens before the MDL updates the is-checked class of the select box, but we can asume the click changed the state of the checkbox since last time, so negating the hasClass on click is a pretty safe bet in determining the checked state in most cases.
function debounce(func, wait, immediate) {
var timeout;
return function() {
var context = this, args = arguments;
var later = function() {
timeout = null;
if (!immediate) func.apply(context, args);
};
var callNow = immediate && !timeout;
clearTimeout(timeout);
timeout = setTimeout(later, wait);
if (callNow) func.apply(context, args);
};
}
$(document).on("click", ".mdl-checkbox", debounce(function (e) {
var isChecked = !$(this).hasClass("is-checked");
console.log(isChecked);
}, 250, true));
Hope it helps ;)
We currently don't have a way directly to figure this out. We are looking into adding events with V1.1 which can be subscribed to at Issue 1210. Remember, just subscribe to the issue using the button on the right hand column. We don't need a bunch of +1's and other unproductive comments flying around.
One way to hack it is to bind an event to the table itself listening to any "change" events. Then you can go up the chain from the event's target to get the table row and then grab the data you need from there.
You could delegate the change event from the containing form.
For example
var form = document.querySelector('form');
form.addEventListener('change', function(e) {
if (!e.target.tagName === 'input' ||
e.target.getAttribute('type') !== 'checkbox') {
return;
}
console.log("checked?" + e.target.checked);
});

What is the 'angular' way of displaying a tooltip / lightbox?

I've been looking around and have not been quite able to get a clear path to the 'angular' way of accomplishing the following. What I'm trying to achieve is displaying a tooltip with information when hovering over a link within an ng-repeat loop. Based on my research, I understood that this is part of the view, and so I should probably handle this in a directive. So, I created an attribute directive called providertooltip. The html declaration is below:
<table>
<tr id="r1" ng-repeat="doc in providers">
<td>
<a providertooltip href="#{{doc.Id}}" ng-mouseover="mouseOverDoc(doc)" ng-mouseleave="mouseLeave()">{{doc.FirstName}} {{doc.LastName}}</a>
</td>
</tr>
</table
<div id="docViewer" style="display:hidden">
<span>{{currentDoc.FirstName}} {{currentDoc.LastName}}</span>
</div>
In the module, I declare my directive, and declare my mouseOver and mouseLeave functions in the directive scope. I also 'emit' an event since this anchor is a child scope of the controller scope for the page. On the controller function (docTable ) which is passed as a controller to a router, I listen for the event. Partial implementation is seen below:
app.directive("providertooltip", function() {
return {
restrict : 'A',
link: function link(scope, element, attrs) {
//hover handler
scope.mouseOverDoc = function(doc){
scope.currentDoc = doc;
scope.$emit('onCurrentDocChange');
element.attr('title',angular.element('#docViewer').html());
element.tooltipster('show');
//docViewer
};
scope.mouseLeave = function() {
element.tooltipster('hide');
}
}
}});
function docTable(docFactory, $scope, $filter, $routeParams) {
$scope.$on('onCurrentDocChange',function(event){
$scope.currentDoc = event.targetScope.currentDoc;
event.stopPropagation();
});
}
Ok, so here is my question. All of the works as expected; Actually, the tooltip doesn't really work so if someone knows a good tooltip library that easily displays div data, please let me know. But, what I'm really confused about is the binding. I have been able to get the tooltip above to work by setting the title ( default tooltip behavior ), but I can see that the binding has not yet occured the first time I hover of a link. I assume that the onCurrentDocChange is not synchronous, so the binding occurs after the tooltip is displayed. If I hover over another link, I see the previous info because as I mentioned the binding occurs in an asynchronous fashion, i.e., calling scope.$emit('onCurrentDocChange') doesn't mean the the parent scope binds by the time the next line is called which shows the tooltip. I have to imagine that this pattern has to occur often out there. One scope does something which should trigger binding on some other part of the page, not necessarily in the same scope. Can someone validate first that the way I'm sending the data from one scope to the other is a valid? Moreover, how do we wait until something is 'bound' before affecting the view. This would be easier if I let the controller mingle with the view, but that is not correct. So, I need the controller to bind data to the scope, then I need the view to 'display a tooltip' for an element with the data. Comments?
To go the angular way correctly start your directive like:
...
directive('showonhover',function() {
return {
link : function(scope, element, attrs) {
element.parent().bind('mouseenter', function() {
element.show();
});
element.parent().bind('mouseleave', function() {
element.hide();
});
}
...
Or start with http://angular-ui.github.io/ link to go the angular-way UI. Look into the bootstrap-ui module - pure angular bootstrap widgets implemented as directives. You can get a clue how the tooltip binding implemented directly from the source of the module - https://github.com/angular-ui/bootstrap/blob/master/src/tooltip/tooltip.js
Also here is another example - (having jQuery and bootstrap scripts included) - use the ui-utils module Jquery passthrough directive ui-jq'. It allows to bind Jquery plugins ( style of $.fn ) directly as angular directive.
Here is their example for binding twitter bootstrap tooltip.
<a title="Easiest. Binding. Ever!" ui-jq="tooltip">
Hover over me for static Tooltip</a>
<a data-original-title="{{tooltip}}" ui-jq="tooltip">Fill the input for a dynamic Tooltip:</a>
<input type="text" ng-model="tooltip" placeholder="Tooltip Content">
<script>
myModule.value('uiJqConfig', {
// The Tooltip namespace
tooltip: {
// Tooltip options. This object will be used as the defaults
placement: 'right'
}
});
</script>
Also look into the official angular documentation for writing directives examples,
and have a happy coding time with Angular!

knockout.js data-bind 'with' conflicts with jQuery change event

For some reason, when I use the data-bind="with: detailedStudent" the jQuery change() binding does not get called. I'm dynamically populating the select options but I'm not sure that should matter. This is some of the code I'm using just to try to give a decent picture of what's going on:
var viewModel;
$(document).ready(function() {
viewModel = new StudentViewModel();
ko.applyBindings(viewModel);
// this change event is not getting called, but if i put the onchange directly into the html as an attribute, it works fine.
$("#accountDialog").find("#mySelect").change(function() {
alert('hi');
}
}
function Student(data) {
var self = this;
ko.mapping.fromJS(data, {}, this);
}
function StudentViewModel() {
var self = this;
this.students = ko.observableArray([]);
this.detailedStudent = ko.observable();
}
<div id="accountDialog" class="modal hide fade" data-bind="with: detailedStudent">
<select id="mySelect" name="mySelect" data-bind="value: GraduationClassId"></select>
</div>
The with binding is a wrapper to the template binding. It copies off the child elements and uses them as the template. So, if your detailedStudent is changing, then KO will be rendering new elements each time that did not have the event handler attached to it.
Some alternatives:
use a binding to attach the event handler (can use event binding)
create a manual subscription against your detailedStudent observable and perform your action in the view model (best option, if your action does not involve DOM manipulation)
try to use a delegated event handler like jQuerys $.on() http://api.jquery.com/on/.
If the action does not involve DOM manipulation, then I agree with RP Niemeyer, the manual subscription is the best option.
However, usually we will have some event with DOM manipulation, for example, to setup the jquery dialog / datepicker plugin to your property. I regard the custom binding would be the best option. The custom binding will work perfectly with the "with" binding clause to setup event handlers to arbitary javascript function.
You could read through this and it is not as hard as it seems to be.
http://knockoutjs.com/documentation/custom-bindings.html

How to access properties of a Tridion component like schema name based on which it is created in aspx page?

I am customizing the ribbon tool bar by adding a button to it in TRIDION 2011 SP1 version.
When I click on the button it will open an aspx page.Inside that aspx page I need to access the name of the schema used to create that component before creating the component itself(I mean to say while creating the component itself).
Please provide me a way to solve this issue. Thanks in advance.
You should pass it to your popup. The URI of the Schema is available on the Component model object within the CME - so your button command can access it and pass it to the popup (in the URL, for example).
var schemaId = $display.getView().getItem().getSchemaId();
If you have the component (as an object), you can get it's schema id as Peter indicated. If you only have the component id, you can load the component and through that get to the schema.
When you need to load any item, you have to be aware that it's not a synchronous call in the UI API, so you should use delegate methods for that. For example something like this:
Example.prototype._loadItemInformation = function Example$_loadItemInformation(itemId, reload) {
var item = $models.getItem(itemId);
if (item) {
var self = this;
function Example$_loadItemInformation$_onItemLoaded() {
$evt.removeEventHandler(item, "load", Example$_loadItemInformation$_onItemLoaded);
// proceed with the actions on the loaded item here
};
if (item.isLoaded(true) && !reload) {
Example$_loadItemInformation$_onItemLoaded();
}
else {
$evt.addEventHandler(item, "load", Example$_loadItemInformation$_onItemLoaded);
//$evt.addEventHandler(item, "loadfailed", Example$_loadItemInformation$_onItemLoadFailed);
item.load(reload, $const.OpenMode.VIEW);
}
}
};
Also be aware the item could fail loading, you should actually also register an event handler for loadfailed (as my example code neglects to do).

dynamically initializing a child component at run time

In a current Flex project, i have an issue where a certain child component must be initialized and ready when the user clicks a button. the button is a mouseClick Event.
//mouseClick Event
protected function tableSearch_searchClickHandler(event:MouseEvent):void
{
parentXml = event.xmlNode;
if(classifierInfo)
classifierInfo.variables = parentXml;
else //initialize it dynamically..but how?
{};
}
in the function the component (classifierInfo) is checked to see if it is initialized and ready== that is, it is not null. then the variables property is populated with the parentXml value else, if it is not ready, [i want to initialize it dynamically] but do not know how.
does any one know how i could fill up the else statement such that the classifierInfo component is initialized dynamically? Is this even possible?
you have to try to initialize the object and add it to the correct parent UI Object if it is a visual component.
classifierInfo = new WhateverClass();
classifierInfo.somePropertySet
...
yourUIComponent.addElement(classifierInfo);
Is it that what you are trying to do?

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