I'm developing an app that receives data from API and should store it in some kind of cache to bind it to UI views. This data is also shared among several views and any change to it should be reflected in views. What is the best and fastest option for NativeScript so far? Would be awesome to have something similar to SenchaTouch stores / models with proxy. Thanks.
Just create a singleton and request/import that, just as you would in any other Javascript app. As long as you keep your data in an Observable and any changes to it will instantly be reflected in the views.
E.g.
file: myData.js
var observableArray = require("data/observable-array");
var observable = require("data/observable");
var DATA = new observable.Observable({
something: 'a value here',
somethingElse: 1
somethingMany: new observableArray.ObservableArray(['a', 'b', 'c'])
});
exports.getData = function() { return DATA; };
exports.fetchFromAPI = function() { /* something that fetches and updates DATA */ }
In any file where you want to read that data:
var data = require("./myData.js");
console.log(data.getData());
Read more about Observables in NativeScript
Related
I'm having trouble passing in the name of an element into a Dyanamics CRM web Resource javacript.
This code works:
function OnFormLoad()
{
var subGrid = window.parent.document.getElementById("Claims")
// do work
}
This code doesn't:
function OnFormLoad(GridName)
{
var subGrid = window.parent.document.getElementById(GridName)
// do work
}
How do I pass in the name of the element I want to work with?
Please refrain from using document.getElementById in Dynamics as it is not supported.
I believe you are trying to get GridContext and get Data from that Grid.
For Example on Account entity we have Contacts as Grid and then you wish to get data from that Grid.
I replicated the same on Account Entity (OnLoad) and get tried to get data from Contacts Grid.
When adding OnLoad event I have passed Grid name as Parameter as below.
I have added below onLoad Js on Account entity and was able to retrieve data from grid.
Note: I have added timeout because directly firing onload was not able to load complete page and then grid Name was not available.
function onLoad(executionContext,gridName){
setTimeout(function(){ getGridDatat(executionContext,gridName); }, 3000);
}
function getGridDatat(executionContext,gridName){
debugger
var formContext = executionContext.getFormContext();
var gridContext = formContext.getControl("Contacts"); // get the grid context
var myRows = gridContext.getGrid().getRows();
/*var myRow = myRows.get(arg);
var gridRowData = myRow.getData();*/
var firstRow =myRows.get(0).getData();
var firstRowAllAttributes = firstrow.entity.attributes.getAll()
var firstRowfirstAttributeValue = firstrow.entity.attributes.get(0).getValue()
}
If you want to perform some operation on change of data formGird then there is one more way to achieve this. Make your grid as Editable and then you can find Events for that gird as below and could perform your operations.
Purpose
I am trying to make a common answer database for a website form. The form is a description of computer hardware specifications, and I am trying to make it so that based on a model field, other fields are filled in automatically. The extension with have two buttons, "populate" which will based on the model field, check the database for a matching entry, and then populate data into the forms based on that. The second button being "save", which will take data in the fields and marry it to the model field and place it into the database.
Question
So, my main question is on interacting with the webpage itself, how do I grab data from the webpage, and then how do I make changes to fields?
So, my main question is on interacting with the webpage itself, how do I grab data from the webpage, and then how do I make changes to fields?
You can do this with a Firefox Add-on SDK Page-mod, click here for the documentation
Here is an example for getting data:
Example Page-Mod
/lib/main.js:
var tag = "p";
var data = require("sdk/self").data;
var pageMod = require("sdk/page-mod");
pageMod.PageMod({
include: "*.mozilla.org",
contentScriptFile: data.url("element-getter.js"),
onAttach: function(worker) {
worker.port.emit("getElements", tag);
worker.port.on("gotElement", function(elementContent) {
console.log(elementContent);
});
}
});
/data/element-getter.js:
self.port.on("getElements", function(tag) {
var elements = document.getElementsByTagName(tag);
for (var i = 0; i < elements.length; i++) {
self.port.emit("gotElement", elements[i].innerHTML);
}
});
Actually I am playing around with sencha touch. Sometimes my stores need to know my views. For example:
Ext.define('Ext.Panel', {
id : 'myId',
config : {
padding: 5,
fullscreen : true
},
moo : null
});
Ext.define('Ext.data.Store', {
fetchSomething : function() {
// Fetch stuff and set moo of view like this:
Ext.getCmp('#myid').moo = 'fetched Data';
}
});
This is a general question.
Is it allowed that the store can set properties of the view?
I think yes, because in a store, if you work with templates and load data, in callback method you can say view.setData(fetchedData).
And is the store a controller or model? Because sometimes I get data from
server and have to change the structure so the view can make it visible.
For example I get an array and make from it a map.
According to best practices, no, absolutely not!!
The sencha touch data system allows views to automatically update themselves when the content of a store changes. You need to use dataviews or the record config along with the tpl config of a view to wire this all up.
I wrote (quite an extensive) post about this for beginners on my blog a while back that will really help you with this (I hope!)
http://senchatouchdev.com/wordpress/2014/01/03/an-overview-of-sencha-touch-2s-data-system/
In brief:
Model = a description of a type of data your app will handle
Record = instance of model
Store = collection of records
View = something displayed on screen
Controller = collection of references/methods that wire your app together
As far as I can tell, Backbone.js view represents DOM element. I take it from existing DOM or create it on the fly in el attribute.
In my case, I want to take it from server with AJAX request because I'm using Django templates and don't want to rewrite everything to JavaScript templates.
So I define el function that performs AJAX request.
el: function() {
model.fetch().success(function(response) {
return response.template
})
}
Of course, it does NOT work because AJAX request is executed asynchronous.
This means that I don't have el attribute and events does NOT work neither. Can I fix it?
Maybe the Backbone.js framework isn't the right tool for my needs? The reason I want to use that was to have some structure for the code.
P.S. I'm new to Backbone.js.
Do your ajax request from another view, or directly after the page load using jquery directly, and after you've downloaded your template, THEN instantiate your backbone view class with the proper id/el or whatever (depending on where you stored your ajax fetched template). Depending on your use-case, this may or may not be a sensible approach.
Another, perhaps more typical approach, would be to set up your view with some placeholder element (saying "loading" or whatever), then fire off the ajax, and after the updated template has been retrieved, then update your view accordingly (replace the placeholder with the actual template you requested).
When/if you update your view with new/other DOM elements, you need to call the view's delegateEvents method to rebind your events to the new elements, see:
http://backbonejs.org/#View-delegateEvents
I came across a similar requirement. In my instance, I was running asp.net and wanted to pull my templates from user controls. The first thing I would recommend is looking into Marionette because it will save you from writing a lot of boiler plate code in Backbone. The next step is to override how your templates are loaded. In this case I created a function that uses Ajax to retrieve the HTML from the server. I found an example of this function where they were using it to pull down html pages so I did a little modification so I can make MVC type requests. I can't remember where I found the idea from; otherwise, I would give the link here.
function JackTemplateLoader(params) {
if (typeof params === 'undefined') params = {};
var TEMPLATE_DIR = params.dir || '';
var file_cache = {};
function get_filename(name) {
if (name.indexOf('-') > -1) name = name.substring(0, name.indexOf('-'));
return TEMPLATE_DIR + name;
}
this.get_template = function (name) {
var template;
var file = get_filename(name);
var file_content;
var result;
if (!(file_content = file_cache[name])) {
$.ajax({
url: file,
async: false,
success: function (data) {
file_content = data; // wrap top-level templates for selection
file_cache[name] = file_content;
}
});
}
//return file_content.find('#' + name).html();
return file_content;
}
this.clear_cache = function () {
template_cache = {};
};
}
The third step would be to override Marionette's method to load templates. I did this in the app.addInitializer method. Here I am initializing my template loader and setting it's directory to a route handler. So when I want to load a template, I just set the template: "templatename" in my view and Backbone will load the template from api/ApplicationScreens/templatename. I am also overriding my template compiling to use Handlebars because ASP.net is not impressed with the <%= %> syntax.
app.JackTemplateLoader = new JackTemplateLoader({ dir: "/api/ApplicationScreens/", ext: '' });
Backbone.Marionette.TemplateCache.prototype.loadTemplate = function (name) {
if (name == undefined) {
return "";
} else {
var template = app.JackTemplateLoader.get_template(name);
return template;
}
};
// compiling
Backbone.Marionette.TemplateCache.prototype.compileTemplate = function (rawTemplate) {
var compiled = Handlebars.compile(rawTemplate);
return compiled;
};
// rendering
Backbone.Marionette.Renderer.render = function (template, data) {
var template = Marionette.TemplateCache.get(template);
return template(data);
}
Hopefully this helps. I've been working on a large dynamic website and it is coming along very nicely. I am constantly being surprised by the overall functionality and flow of using Marionette and Backbone.js.
How do you keep track of your UI elements in Titanium? Say you have a window with a TableView that has some Switches (on/off) in it and you'd like to reference the changed switch onchange with a generic event listener. There's the property event.source, but you still don't really know what field of a form was just toggled, you just have a reference to the element. Is there a way to give the element an ID, as you would with a radiobutton in JavaScript?
Up to now, registered each form UI element in a dictionary, and saved all the values at once, looping through the dictionary and getting each object value. But now I'd like to do this onchange, and I can't find any other way to do it than create a specific callback function for each element (which I'd really rather not).
just assign and id to the element... all of these other solution CAN work, but they seem to be over kill for what you are asking for.
// create switch with id
var switcher0 = Ti.Ui.createSwitch({id:"switch1"});
then inside your event listener
myform.addEventListener('click', function(e){
var obj = e.source;
if ( obj.id == "switch1" ) {
// do some magic!!
}
});
A simple solution is to use a framework that helps you keep track of all your elements, which speeds up development quite a bit, as the project and app grows. I've built a framework of my own called Adamantium.js, which lets you use a syntax like jQuery to deal with your elements, based on ID and type selectors. In a coming release, it will also support for something like classes, that can be arbitrarily added or removed from an element, tracking of master/slave relationships and basic filter methods, to help you narrow your query. Most methods are chainable, so building apps with rich interaction is quick and simple.
A quick demo:
// Type selector, selects all switches
$(':Switch')
// Bind a callback to the change event on all switches
// This callback is also inherited by all new switch elements
$(':Switch').bind('change', function (e) {
alert(e.type + ' fired on ' + e.source.id + ', value = ' + e.value);
});
// Select by ID and trigger an event
$('#MyCustomSwitch').trigger('change', {
foo: 'bar'
});
Then there's a lot of other cool methods in the framework, that are all designed to speed up development and modeled after the familiar ways of jQuery, more about that in the original blog post.
I completely understand not wanting to write a listener to each one because that is very time consuming. I had the same problem that you did and solved it like so.
var switches = [];
function createSwitch(i) {
switches[i] = Ti.UI.createSwitch();
switches[i].addEventListener('change', function(e) {
Ti.API.info('switch '+i+' = '+e.value);
});
return switches[i];
}
for(i=0;i<rows.length;i++) {
row = Ti.UI.createTableViewRow();
row.add(createSwitch(i));
}
However keep in mind that this solution may not fit your needs as it did mine. For me it was good because each time I created a switch it added a listener to it dynamically then I could simply get the e.source.parent of the switch to interact with whatever I needed.
module Id just for the hold it's ID. When we have use id the call any another space just use . and use easily.
Try This
var but1 = Ti.Ui.createButton({title : 'Button', id:"1"});
window.addEventListener('click', function(e){
var obj = e.source;
if ( obj.id == "1" ) {
// do some magic!!
}
});
window.add(but1);
I, think this is supported for you.
how do you create your tableview and your switcher? usually i would define a eventListener function while creating the switcher.
// first switch
var switcher0 = Ti.Ui.createSwitch();
switch0.addEventListener('change',function(e){});
myTableViewRow.add(switch0);
myTableView.add(myTableViewRow);
// second switch
var switch1 = ..
so no generic event listener is needed.