data-tier

Overview

data-tier ('tier' from 'to tie') is a two way binding (MVVM) service targeting client (browser) HTML/Javascript applications. data-tier.js relies on an Observable-driven event cycle, having an embedded object-observer as the default Observable provider.

It is possible to provide custom Observable implementation. In this case you may want to use lighter data-tier-wo-oo.js where object-observer.js opted out.

Support matrix: ₄₉₊, ₄₄₊, ₁₃₊

Support matrix is currently as wide as that of object-observer, assuming that in most of the cases consumers will not provide their own object observer, but will use an embedded one. data-tier supports custom elements as well, obviously this functionality is available only on supporting environments.

Versions

0.6.11

• Fixed issue no. 8
• Fixed issue no. 9
• Minor performance improvements

0.6.10

• Added a possibility to create/update Tie's data with a plain JS object, in this case data-tier will attempt to auto-create and use Observable from it, using an embedded Observable implementation
• Fixed issue no. 7

0.6.9

• Conceptually Rule has been replaced by Controller. There are still no API changes with regard to that, nor any API are yet published, but there will be some refactoring in this area in future releases
• Fixed issue no. 6, some performance improvements made for a large scale DOM manipulations

0.6.8

• Fixes: issue no. 2 (smooth handling of an empty values given to the controllers definition), issue no. 4 (non working repeaters on subgraph list), issue no. 5 (improvements of data-tie-classes)

0.6.7

• Added a possibility to create a tie without providing any initial data, for early setup with lazy data provisioning

0.6.5

• Fixed a case that element having no dataset breaks the views collection flow (this is not a valid case, but see this issue in Edge, so got to be defensive here)
• Added tieSrc rule and removed obsolete tieImage rule (did the same as tieSrc, just in a less general flavor)
• Added tieHRef rule
• Added tieClasses rule

0.6.0

• Moved to object-observer.js library as an observation engine, were impacted both the API and the implementation.

0.5.41

• First version, based on native Object.observe technology.

Loading the Library

There are 2 ways to load the library: into a window global scope, or a custom scope provided by you.

• Simple reference (script tag) to the data-tier.js/data-tier.min.js in your HTML will load it into the global scope:

<script src="data-tier.min.js"></script>
<script>
	let person = { name: 'Uriya', age: 8 },
	    observablePerson = Observable.from(person);
	DataTier.ties.create('person', observablePerson);
	DataTier.ties.create('settings', {});
</script>

• The snippet below exemplifies how to load the library into a custom scope (add error handling as appropriate):

let customNamespace = {},
    person = { name: 'Nava', age: 6 },
    observablePerson;

fetch('data-tier.min.js').then(function (response) {
	if (response.status === 200) {
		response.text().then(function (code) {
			Function(code).call(customNamespace);
			
			//	the below code is an example of consumption, locate it in your app lifecycle/flow as appropriate
			observablePerson = customNamespace.Observable.from(person);
			customNamespace.DataTier.ties.create('person', observablePerson);
		});
	}
});

• Note the usage of an embedded Observable along the way. As it has been mentioned before, you may provide your own Observable implementation and in this case more lightweight data-tier-wo-oo.js/data-tier-wo-oo.min.js may suite you more
• If an embedded object-observer employed, it is even more preferable to create the Tie from a plain JS object
• Minified version is also available for both distributions, with and without object-observer.js

Basic concepts

The library utilizes 2 main concepts: Tie and Controller.

Tie

Tie holds an observable data structure associated with tie's name, it's about what to tie. Thus, ties serve most and foremost data segregation and management purposes.

Thus, having the following data structure:

let bands = [
	{
		id: 1234,
		name: 'Dream Theater',
		since: 1985,
		albums: [
			{ id: 2345, name: 'When Dream and Day Unite', since: 1988 },
			{ id: 2346, name: 'Images and Words', since: 1991 }
		]
	}
];
bands.totalTooltip = generateTooltipText();

one can create a tie named, say, 'bandsTie', setting its data to be (an observable clone of) the bands array:

let bandsDataStore = DataTier.ties.create('bandsTie', bands);

//  or ...DataTier.ties.create('bandsTie', Observable.from(bands));

and then tie any UI element to it via the tie name and the path:

<span data-tie-text="bandsTie.length"
	  data-tie-tooltip="bandsTie.totalTooltip">
</span>

<div>
	<template data-tie-list="bandsTie.0.albums => album">
		<span data-tie-text="album.name"></span>
	</template>
</div>

where:

• the first item in the path is always the tie's name
• bandsTie.0 - refer to the whole object at index 0 of our array
• bandsTie.length - length property, inherited from the native Array, may also be used
• bandsTie.0.name - path can get deeper...
• bandsTie.0.albums.1.since - ...actually, it can get to any level of deepness

Basically, it is possible to create a single dataset for the whole application, making a single 'uber-tie' from it and operating everything from there, but it should be considered as a bad practice. Having say that, I'll note, that there is no limitations on the size or the structure complexity of the tied model, nor there are any negative effects of those on application performance.

Tie object not only meant to hold the link between the data and its namespace, but also tie's specific configurations/customizations and data management APIs. For more details see API reference.

Controller

Controller is a holder of the transition logic, it's about how to translate the data from/to view/data.

Each controller has it's own unique name given to it upon registration. Controllers are applied via the DOM's data-* attributes joining the data- prefix with rule's name: for example data-tie-text employs the controller 'tieText'.

<span data-tie-text="bandsTie.length"
	  data-tie-tooltip="bandsTie.totalTooltip">
</span>

<div>
	<template data-tie-list="bandsTie.0.albums => album">
		<span data-tie-text="album.name"></span>
	</template>
</div>

In the first part we tie between the span (view) and the model (we have tied it to both, length and totalTooltip values), while using 2 different OOTB controllers: 'tieText', 'tieTooltip'. Attributes' values (bandsTie.length, bandsTie.totalTooltip) are controllers' configurations for this specific instance and their syntax/content is part of each controller's own API.

Thus, in the second part a template element tied by another OOTB controller: 'tieList'. This one expects a richer content in its configuration: tie name and path for sure, but also some name for an item within iteration (here - 'album', and see its usage in the inner span element).

OOTB provided controllers reviewed in the Controllers reference. This set will eventually be updated and enhanced.

But even more important is the fact, that any custom controllers may be provided by the consuming application. This can be done at any phase of application's lifecycle, so that there is no special ceremony around it whatsoever. Controllers' management described in the relevant section in API reference.

Documentation

Tutorials

API reference

OOTB Controllers reference