I am working on my first bigger Polymer application and currently have around 30 components. Most of the components need to be able to display (modal) message boxes. For this I implemented a message box component wrapping paper-dialog (similar to other message box components available).
What I don't like is that in every component which wants to display message boxes I need to define an element
<my-message-box id="message-box"></my-message-box>
and then call it like this
this.$["message-box"].information("Something happened...");
This works but my gut feeling is that a message box should be more like a global service, a singleton maybe. In C# f.e. there exists a static method on the MessageBox class.
Is the above mechanism really the recommended way to do it or are there better solutions to it?
My current approach is to create error-dialog and add it as a sibling to my main-app in index.html:
<body>
<main-app></main-app>
<error-dialog></error-dialog>
<noscript>
Please enable JavaScript to view this website.
</noscript>
</body>
error-dialog's ready() method adds a custom event:
ready() {
super.ready();
this.addEventListener('o_error', e => this._errorListener(e));
}
_errorListener(e) {
this.o_error = e.detail;
this.$.errorDlog.open();
}
Now I can open error-dialog from anywhere with
let msg = ...
const dlog = document.querySelector('error-dialog');
dlog.dispatchEvent(new CustomEvent('o_error', {detail: msg, bubbles: true, composed: true}));
Related
I have multiple elements on a page that are triggering a load of select2 to the element. I'm trying to conditionally check if the element has a certain class, and if so add the tag option; otherwise do not. I thought something like this would work, but it's not:
$('.element_to_add_select_two_on').select2({
tags:function(element) {
return (element.className === 'classname_i_am_targeting');
},
});
What am I missing here? I'm subjecting myself to the following buffoonery to get this to target and load:
$('.element_to_add_select_two_on').each((index,element) => {
let showTags = false;
if ($(element).attr('class').split(' ').includes('classname_i_am_targeting')) {
showTags = true;
}
$(element).select2({
tags:showTags,
});
});
There are a few problems with your first attempt. First, you are defining tags as a function when what you want is the result of the function, since tags needs to be defined as a boolean true or false. The other is that inside your .select2() call, you do not have access to the calling element $('.element_to_add_select_two_on') in the way that you think. It isn't an event that you are listening on, it's a function call that wants an object passed with its configuration.
You conveyed that your second method works, but it can be simplified with the jQuery hasClass() function:
$('.element_to_add_select_two_on').each((index, element) => {
$(element).select2({
tags: $(element).hasClass('classname_i_am_targeting'),
});
});
There is a much simpler way to do all of this, however, and it is much more flexible and already built into select2 via the way of data-* attributes (note, you need jQuery > 1.x). You can simply add data-tags="true" to any of your select elements with which you want tags enabled. These will override any configuration options used when initializing select2 as well as any defaults:
<select data-tags="true">
...
</select>
I inherited an Adobe CEP extension at work. Trying to wrap my head around an issue that makes it so absolutely no input from keyboard works on text inputs. To elaborate, absolutely no keyboard input works in Polymer's text inputs. The input get's focused, but if I type anything in them I get the mac error alert sound. The only key that I was able to make work was "tab". Anything else does not work. It's built using Polymer. At first I was unsure what's causing the issue, and since I inherited this project I was confused where to start. After about a day of debugging, I believe it's related to Polymer somehow. The reason for this is, if I remove the Polymer HTML element that renders it, and just put an input there, the input works. It only seems to block input inside the <template> ... </template>. I've looked all over the internet for any clues on what could be causing Polymer to block this input, there's no errors in console or anything, and I've come up short handed.
Does anyone have any insight on this?
I'm facing the same problem. Actually, it is not related to polymer, but to the webcomponents polyfill. If you try the following source code inside an Adobe CEP extension, you will see that you can click inside both the elements, select any text, but you are not able to edit it.
<html>
<head>
<script>
// Force all polyfills on
if (window.customElements) window.customElements.forcePolyfill = true;
ShadyDOM = {
force: true
};
ShadyCSS = {
shimcssproperties: true
};
</script>
<script src="node_modules/#webcomponents/webcomponentsjs/webcomponents-loader.js"></script>
</head>
<body>
<template id="x-foo-from-template">
<input value="from template">
</template>
<script>
let tmpl = document.querySelector('#x-foo-from-template');
customElements.define('x-foo-from-template', class extends HTMLElement {
constructor() {
super();
let shadowRoot = this.attachShadow({
mode: 'open'
});
shadowRoot.appendChild(tmpl.content.cloneNode(true));
}
});
customElements.define('x-foo-from-dynamic', class extends HTMLElement {
constructor() {
super();
let shadowRoot = this.attachShadow({
mode: 'open'
});
var inputEl = document.createElement('input');
inputEl.value = "from created element";
shadowRoot.appendChild(inputEl);
}
});
</script>
<x-foo-from-template></x-foo-from-template>
<x-foo-from-dynamic></x-foo-from-dynamic>
</body>
</html>
Faced with the same issue, we finally found documented that Adobe will hand over all keypresses to the host application unless it can determine that an input or dropdown element has focus. I expect this is done using a simple check on document.activeElement. When the Shadow DOM is involved, Adobe would have to do something like
let target = document.activeElement;
while (target.shadowRoot && target.shadowRoot.activeElement) {
target = target.shadowRoot.activeElement;
}
in order to find the underlying <input> element.
Since this is currently not working, we needed to use registerKeyEventsInterest to explicitly have all keypresses be processed by our code.
var csInterface = new CSInterface();
var keyEvents = [];
// All the keyCodes you need, with the modifiers used
keyEvents.push({ keyCode: 0 });
keyEvents.push({ keyCode: 0, metaKey: true });
// ...
csInterface.registerKeyEventsInterest(JSON.stringify(keyEvents));
We actually went ahead and looped 0..255 and registered for all modifiers. With the exception of keyboard based copy-paste, we now have full functionality with our webcomponents (mostly PolymerElement/LitElement based).
https://github.com/Adobe-CEP/CEP-Resources/blob/master/CEP_8.x/Documentation/CEP%208.0%20HTML%20Extension%20Cookbook.md#register-an-interest-in-specific-key-events
I'm wondering, is there a possibility to have databindings "out of" a template? Say I have a <template/>-Tag somewhere which I put into the slot of a different component - that component stamps it to its context. Then I want to bind data from the root element to the <template/>-Tag. Also, event bindings (on-x-changed) don't work, because you can't assign a function which is defined in the hosting component. Any ideas?
Example:
... host
{{boundData}}
<binding-component>
<template>
{{boundData}}
</template>
</binding-component>
I don't see changes when I observe boundData in the hosting component. Is there a way to get around this? Or is firing a custom event my only chance?
If you are looking for binding a property outside of polymer something like from index.html you may bind value with element. an example ; index.html
<dom-bind>
<template>
<binding-component bound-data="{{boundData}}"></binding-component>
</template>
</dom-bind>
<script>
// set a value a string, Number or Object etc.
// Optionally wrap this code into a listener ie;
// window.addEventListener('load', e=> { ...below code ... })
var boundData= document.querySelector('dom-bind');
boundData = {} //
</script>
Now in your binding-component element has a property as boundData
hope its helps or provide more code to understand better.
I've made it work the way dom-if does it, too. Like in dom-if (reference), I'm creating a Templatize-instance which then uses forwardHostProp to handle the "inside"-properties
this.__ctor = Templatize.templatize(template, this, {
mutableData: true,
forwardHostProp(prop, value) {
// handling item updates, item being the only property
// from within the binding component
// everything else is automatically bound by templatize
this.set(prop, value);
this.update(this.item);
},
});
this.__instance = new this.__ctor();
this.root.appendChild(this.__instance.root);
This all happens in connectedCallback.
Because the Templatize-instance is passed this, it's bound to the current context as well.
Good luck!
Using Polymer Starter Kit as an example, I would like to have different <app-toolbar> in <my-app> (using property headerType) based on different <my-view#>, i.e.
<my-view1> => headerType = 'my-view1-header'
<my-view2> => headerType = 'my-view2-header'
In my <my-app>, I have created a property headerType and use <dom-if> to show/hide different <app-toolbar>.
My question is how would I always fire an event to <my-app> and set headerType = my-view#-header whenever <my-view#> is active (i.e. comes into view).
I have tried the polymer lifecycle, such as ready(), attached(), etc, and I understand they are only trigger during dom-related events.
I eventually use the _pageChanged observer to call a function on <my-view#>. Below are the snippet of the code.
_pageChanged: function(page) {
let onLoad = function () {
let selected = this.$.ironpages.children[page];
if (Object.getPrototypeOf(selected).hasOwnProperty('viewSelected')) {
selected.viewSelected();
}
}
// Load page import on demand. Show 404 page if fails
var resolvedPageUrl = this.resolveUrl('my-' + page + '.html');
this.importHref(resolvedPageUrl, onLoad, this._showPage404, true);
},
There is some example in Polymer shop template where you can execute something when the visibility of your view change with iron-pages.
you just need to add a property for example visible in each of your view element with Boolean type and observe that property to check whatever the view is visible or not, and then in your iron-pages you need to add selected-attribute property and the value is visible. check Polymer Shop Template.
I am not sure what the proper heading / title for this question should be. I am new to WinJS and am coming from a .NET webform and winclient background.
Here is my scenario. I have a navigation WinJS application. My structure is:
default.html
(navigation controller)
(settings flyout)
pages/Home.html
pages/Page2.html
So at the top of the default.js file, it sets the following variables:
var app = WinJS.Application;
var activation = Windows.ApplicationModel.Activation;
var nav = WinJS.Navigation;
It seems like I cannot use these variables anywhere inside my settings flyout or any of my pages:ready functions. They are only scoped to the default.js?
In the same regard, are there resources on the interwebs (links) that show how to properly share variables, events, and data between each of my "pages"?
The scenario that I immediately need to overcome is settings. In my settings flyout, I read and allow the user to optionally set the following application setting:
var applicationData = Windows.Storage.ApplicationData.current;
var localSettings = applicationData.localSettings;
localSettings.values["appLocation"] = {string set by the user};
I want to respond to that event in either my default.js file or even one of my navigation pages but I don't know where to "listen". My gut is to listen for the afterhide event but how do I scope that back to the page where I want to listen from?
Bryan. codefoster here. If you move the lines you mentioned...
var app = WinJS.Application;
var activation = Windows.ApplicationModel.Activation;
var nav = WinJS.Navigation;
...up and out of the immediate function, they'll be in global scope and you'll have access to them everywhere. That's one of the first things I do in my apps. You'll hear warnings about using global scope, but what people are trying to avoid is the pattern of dropping everything in global scope. As long as you control what you put in there, you're fine.
So put them before the beginning of the immediate function on default.js...
//stuff here is scoped globally
var app = WinJS.Application;
var activation = Windows.ApplicationModel.Activation;
var nav = WinJS.Navigation;
(function () {
//stuff here is scoped to this file only
})();
If you are saving some data and only need it in memory, you can just hang it off the app variable instead of saving it into local storage. That will make it available to the whole app.
//on Page2.js
app.myCustomVariable = "some value";
//on Page3.js
if(app.myCustomVariable == "some value") ...
Regarding your immediate need:
like mentioned in the other answer, you can use datachanged event.
Regards sharing variables:
If there are variables that you would like to keep global to the application, they can be placed outside the anonymous function like mentioned in the Jeremy answer. Typically, that is done in default.js. Need to ensure that scripts using the global variables are placed after the script defining the global variable - in default.html. Typically - such variable will point to singleton class. For example: I use it in one of my apps to store authclient/serviceclient for the backend service for the app. That way - the view models of the multiple pages need not create instance of the object or reference it under WinJS namespace.
WinJS has also concept of Namespace which lets you organize your functions and classes. Example:
WinJS.Namespace.define('Utils.Http',
{
stringifyParameters: function stringifyParameters(parameters)
{
var result = '';
for (var parameterName in parameters)
{
result += encodeURIComponent(parameterName) + '=' + encodeURIComponent(parameters[parameterName]) + '&';
}
if (result.length > 0)
{
result = result.substr(0, result.length - 1);
}
return result;
},
}
When navigating to a page using WinJS.Navigation.navigate, second argument initialState is available as options parameter to the ready event handler for the page. This would be recommended way to pass arguments to the page unless this it is application data or session state. Application data/session state needs to be handled separately and needs a separate discussion on its own. Application navigation history is persisted by the winjs library; it ensures that if the app is launched again after suspension - options will be passed again to the page when navigated. It is good to keep the properties in options object as simple primitive types.
Regards events:
Typically, apps consume events from winjs library. That can be done by registering the event handler using addEventListener or setting event properties like onclick etc. on the element. Event handlers are typically registered in the ready event handler for the page.
If you are writing your own custom control or sometimes in your view model, you may have to expose custom events. Winjs.UI.DOMEventMixin, WinJS.Utilities.createEventProperties can be mixed with your class using WinJS.Class.mix. Example:
WinJS.Class.mix(MyViewModel,
WinJS.Utilities.createEventProperties('customEvent'),
WinJS.UI.DOMEventMixin);
Most often used is binding to make your view model - observable. Refer the respective samples and api documentation for details. Example:
WinJS.Class.mix(MyViewModel,
WinJS.Binding.mixin,
WinJS.Binding.expandProperties({ items: '' }));
Here is what I ended up doing which is kinda of a combination of all the answers given:
Created a ViewModel.Settings.js file:
(function () {
"use strict";
WinJS.Namespace.define("ViewModel", {
Setting: WinJS.Binding.as({
Name: '',
Value: ''
}),
SettingsList: new WinJS.Binding.List(),
});
})();
Added that file to my default.html (navigation container page)
<script src="/js/VMs/ViewModel.Settings.js"></script>
Add the following to set the defaults and start 'listening' for changes
//add some fake settings (defaults on app load)
ViewModel.SettingsList.push({
Name: "favorite-color",
Value: "red"
});
// listen for events
var vm = ViewModel.SettingsList;
vm.oniteminserted = function (e) {
console.log("item added");
}
vm.onitemmutated = function (e) {
console.log("item mutated");
}
vm.onitemchanged = function (e) {
console.log("item changed");
}
vm.onitemremoved = function (e) {
console.log("item removed");
}
Then, within my application (pages) or my settings page, I can cause the settings events to be fired:
// thie fires the oniteminserted
ViewModel.SettingsList.push({
Name: "favorite-sport",
Value: "Baseball"
});
// this fires the itemmutated event
ViewModel.SettingsList.getAt(0).Value = "yellow";
ViewModel.SettingsList.notifyMutated(0);
// this fires the itemchanged event
ViewModel.SettingsList.setAt(0, {
Name: "favorite-color",
Value: "blue"
});
// this fires the itemremoved event
ViewModel.SettingsList.pop(); // removes the last item
When you change data that needs to be updated in real time, call applicationData.signalDataChanged(). Then in the places that care about getting change notifications, listen to the datachanged on the applicationData object. This is also the event that is raised when roaming settings are synchronized between computers.
I've found that many times, an instant notification (raised event) is unnecessary, though. I just query the setting again when the value is needed (in ready for example).