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Component Model Use Cases: Difference between revisions
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{{obsolete|see=http://www.w3.org/2008/webapps/wiki/Component_Model_Use_Cases}} | |||
These use cases represent a set of problems we are trying to solve by implementing a [[Component_Model | component model]] for the web. | |||
= | =Custom Controls= | ||
Current practice for sizable web applications is to use JavaScript libraries to provide a system to support the construction of custom controls. Implementing these controls can be made simpler and more interoperable with runtime support. | |||
==Layout Manager== | ==Layout Manager== | ||
{| cellpadding="8" cellspacing="0" | |||
|+style="caption-side:top; text-align: left; color:Gray" | Layout Manager Use Case Parameters | |||
! align="right" valign="top" | Who | |||
| Web Framework Engineer | |||
|- | |||
! align="right" valign="top" | What | |||
| Build a layout library, consisting of a UI layout primitives, such as ''panel'', ''resizeable panel'', ''tab group'', ''stack'', ''accordion containers'', etc. | |||
|- | |||
! align="right" valign="top" | Purpose | |||
| | |||
* Allow web application developers to easily build constrained layout and populate it with arbitrary HTML content. | |||
* Provide a way for developers to build their own layout primitives by extending the provided ones. | |||
|- | |||
! align="right" valign="top" | Examples | |||
| | |||
* [http://dojotoolkit.org/reference-guide/dijit/layout.html#dijit-layout Dijit Layout] | |||
== | * [http://code.google.com/webtoolkit/doc/latest/DevGuideUiPanels.html GWT Panels] | ||
* [http://dev.sencha.com/deploy/ext-4.0.2a/docs/#/api/Ext.panel.AbstractPanel Sencha Panels] | |||
* [http://guides.sproutcore.com/views.html SproutCore Views] | |||
''' | |- | ||
! align="right" valign="top" | Desirable Properties | |||
= | | | ||
* [[Component_Model#Composability | Composability]] -- a method to compose layouts with both UI primitives and DOM elements. | |||
* [[Component_Model#Extensibility | Extensibility]] -- a way to build on layout primitives to create new ones. | |||
* [[Component_Model#Encapsulation | Encapsulation]] -- styles, defined to hold layout in place should not be in danger of being stomped on by the author stylesheets. | |||
* [[Component_Model#Performance | Performance]] -- layouts built with layout manager should appear quickly, avoiding re-flows and [http://en.wikipedia.org/wiki/Flash_of_unstyled_content FOUC]-like symptoms. | |||
|} | |||
==Widget Mix-and-Match== | |||
{| cellpadding="8" cellspacing="0" | |||
|+ style="caption-side:top; text-align: left; color:Gray" | Mix-and-matching Use Case Parameters | |||
} | ! align="right" valign="top" | Who | ||
| Web Application Engineer | |||
|- | |||
! align="right" valign="top" | What | |||
| Build an application using multiple existing controls from several frameworks. | |||
|- | |||
! align="right" valign="top" | Purpose | |||
| | |||
* Write application faster by reusing code. | |||
* Avoid having to exclusively go with one framework. | |||
|- | |||
! align="right" valign="top" | Examples | |||
| | |||
* [http://stackoverflow.com/questions/4534274/how-do-you-access-dijit-elements-in-jquery How do you access Dijit elements in JQuery] | |||
* [http://yehudakatz.com/2011/06/11/using-sproutcore-2-0-with-jquery-ui/ Using SproutCore 2.0 with jQuery UI] | |||
* [http://stackoverflow.com/questions/394601/which-javascript-framework-jquery-vs-dojo-vs Which JavaScript framework (jQuery vs Dojo vs … )?] | |||
|- | |||
! align="right" valign="top" | Desirable Properties | |||
| | |||
* [[Component_Model#Consistency | Consistency]] -- a compatible way to expose properties and methods across widget frameworks. | |||
* [[Component_Model#Composability | Composability]] -- a method to compose with cross-framework widgets. | |||
|} | |||
==Rendering Form Controls with SVG== | |||
{| cellpadding="8" cellspacing="0" | |||
|+ style="caption-side:top; text-align: left; color:Gray" | SVG Form Controls Use Case Parameters | |||
! align="right" valign="top" | Who | |||
| Web Application Engineer or Web Framework Engineer | |||
|- | |||
! align="right" valign="top" | What | |||
| Create a set of UI controls that act like standard HTML forms controls, but use SVG for rendering. | |||
|- | |||
! align="right" valign="top" | Purpose | |||
| | |||
* Provide custom appearance of form controls, consistent with overall the Web application theme. | |||
* Make the form controls scale beautifully for various resolutions and form factors. | |||
|- | |||
! align="right" valign="top" | Examples | |||
| | |||
[http://docs.sproutcore.com/#doc=SC.ImageButtonView&src=false SproutCore's ImageButtonView], [http://dev.sencha.com/deploy/touch/docs/?class=Ext.form.Number Sencha's Number] -- examples of extensive themed form control hierarchy. | |||
|- | |||
! align="right" valign="top" | Desirable Properties | |||
| | |||
* [[Component_Model#Consistency | Consistency]] -- the controls should act just like any other DOM elements. | |||
* [[Component_Model#Encapsulation | Encapsulation]] -- the document shouldn't be able to accidentally mess up the rendering of the controls. | |||
* [[Component_Model#Performance | Performance]] -- load quickly, avoid [http://en.wikipedia.org/wiki/Flash_of_unstyled_content FOUC]-like symptoms when using controls. | |||
|} | |||
== | ==Contacts Widget== | ||
{| cellpadding="8" cellspacing="0" | |||
|+ style="caption-side:top; text-align: left; color:Gray" | Contacts Widget Use Case Parameters | |||
! align="right" valign="top" | Who | |||
| Web Application Engineer | |||
} | |- | ||
! align="right" valign="top" | What | |||
| Build a drop-in Contacts widget, which has a pre-defined appearance and shows a list of your contacts, with a way to change the widget to compact or full view and to tell the widget to refresh its state. | |||
|- | |||
! align="right" valign="top" | Purpose | |||
| | |||
* Use the widget anywhere in the application without having to worry about styles affecting its appearance. | |||
* Hide details of loading contact data and other plumbing of the widget from the consuming code with a stable API. | |||
|- | |||
! align="right" valign="top" | Examples | |||
| [http://i.imgur.com/4eDXM.png A screenshot of Google+ "in your circles" widget] | |||
|- | |||
! align="right" valign="top" | Desirable Properties | |||
| | |||
* [[Component_Model#Encapsulation | Encapsulation]] -- means to ensure style of the document does not affect the widget, and widget's logic is kept to the widget. | |||
* [[Component_Model#Composability | Composability]] -- easily added anywhere in the DOM tree. | |||
|} | |||
==Like/+1 Button== | |||
{| cellpadding="8" cellspacing="0" | |||
|+ style="caption-side:top; text-align: left; color:Gray" | Like/+1 Button Use Case Parameters | |||
! align="right" valign="top" | Who | |||
| Web Application Engineer | |||
|- | |||
! align="right" valign="top" | What | |||
| Build a drop-in widget with a pre-defined appearance of a button, showing a count of likes/+1s for this instance of a button (count is stored at a central location), embeddable on any document on the Web. | |||
|- | |||
} | ! align="right" valign="top" | Purpose | ||
| | |||
* Provide a simple vehicle for Web authors to embed the button. | |||
* Isolate widget implementation details from the document. | |||
|- | |||
! align="right" valign="top" | Examples | |||
| | |||
* [http://developers.facebook.com/docs/reference/plugins/like/ Facebook Like button embedding instructions] | |||
* [http://www.google.com/webmasters/+1/button/ Google +1 button embedding instructions] | |||
|- | |||
! align="right" valign="top" | Desirable Properties | |||
| | |||
* [[Component_Model#Encapsulation | Encapsulation]] -- means to ensure style of the document does not affect the widget, and widget's logic is kept to the widget. | |||
* [[Component_Model#Confinement | Confinement]] -- a way to completely isolate the widget implementation from the document in which it is being embedded. | |||
* [[Component_Model#Performance | Performance]] -- don't block the page load. | |||
|} | |||
==Table-based Charts== | |||
== | {| cellpadding="8" cellspacing="0" | ||
|+ style="caption-side:top; text-align: left; color:Gray" | Table-based Charts Use Case Parameters | |||
! align="right" valign="top" | Who | |||
| Web Framework Engineer | |||
# | |- | ||
! align="right" valign="top" | What | |||
| Provide a way to represent table data markup as charts or diagrams. | |||
|- | |||
! align="right" valign="top" | Purpose | |||
| Make it easy for Web authors to create charts and diagrams using table markup. | |||
|- | |||
! align="right" valign="top" | Examples | |||
| | |||
* [http://www.wait-till-i.com/2008/01/08/generating-charts-from-accessible-data-tables-using-the-google-charts-api/ Christian Heilmann's tochart script] | |||
|- | |||
! align="right" valign="top" | Desirable Properties | |||
| | |||
* [[Component_Model#Composability | Composability]] -- one should be able to make chart by creating a table, imperatively or declaratively. | |||
* [[Component_Model#Performance | Performance]] -- no FOUC or blocking load when charts are loaded. | |||
|} | |||
== | ==Timezone selection via Image== | ||
== | {| cellpadding="8" cellspacing="0" | ||
|+ style="caption-side:top; text-align: left; color:Gray" | Timezone selection via Image Use Case Parameters | |||
! align="right" valign="top" | Who | |||
| Web Framework Engineer | |||
|- | |||
! align="right" valign="top" | What | |||
| Graphical representation of a timezone selector that shows a world map in addition to/instead of a drop-down list. | |||
|- | |||
! align="right" valign="top" | Purpose | |||
| Make it easy for Web authors to spruce up time zone selection (or similar). | |||
|- | |||
! align="right" valign="top" | Examples | |||
| | |||
* [http://www.timezonecheck.com Time Zone Map] | |||
|- | |||
! align="right" valign="top" | Desirable Properties | |||
| | |||
* [[Component_Model#Extensibility | Extensibility]] -- Basically extending <select>. Should fall back to a simple <select> where components are not supported. | |||
* [[Component_Model#Consistency | Consistency]] -- Extend the <select> API for item selection. | |||
|} | |||
== | ==Entry-helper== | ||
== | {| cellpadding="8" cellspacing="0" | ||
|+ style="caption-side:top; text-align: left; color:Gray" | Entry-helper Use Case Parameters | |||
* | ! align="right" valign="top" | Who | ||
* | | Web Framework Engineer, Web Application Engineer | ||
|- | |||
! align="right" valign="top" | What | |||
| Add an entry-helper (drop-down) list to input fields. | |||
|- | |||
! align="right" valign="top" | Purpose | |||
| | |||
Help the user fill in a form field, show suggestions and acceptable values, speed up data entry. | |||
|- | |||
! align="right" valign="top" | Examples | |||
| | |||
* Most browser's address bar or web search field | |||
|- | |||
! align="right" valign="top" | Desirable Properties | |||
| | |||
* [[Component_Model#Extensibility | Extensibility]] -- Basically extending <input>. Should fall back to a simple <input> where components are not supported. | |||
|} | |||
== | =Built-in HTML Elements= | ||
Many non-trivial (i.e. with additional behavior and styling beyond the standard box model) elements that exist in HTML today could be implemented using HTML/CSS/JS. It makes sense to provide a standardized way to accomplish this, with the short-term goals of reducing the size of browsers C++ code and making new element implementation easier, and the long-term goal of converging built-in HTML element implementations across browsers. | |||
== | {| cellpadding="8" cellspacing="0" | ||
|+ style="caption-side:top; text-align: left; color:Gray" | Built-in HTML Elements Use Case Parameters | |||
! align="right" valign="top" | Who | |||
| Browser Engineer | |||
|- | |||
! align="right" valign="top" | What | |||
| Implement a built-in HTML element by composing or extending existing HTML elements | |||
|- | |||
! align="right" valign="top" | Purpose | |||
| | |||
* Reduce amount of custom UI code (fewer bugs, less code rot, leading to fewer future bugs). | |||
* Remove magic: make it easier for authors to grok control behavior in familiar terms, allow authors to style controls using CSS. | |||
* ''Stretch'': specify built-in element behavior in terms of the component model specification. | |||
|- | |||
! align="right" valign="top" | Desirable Properties | |||
| | |||
* [[Component_Model#Encapsulation | Encapsulation]] -- ensure that implementation details are not exposed to the document | |||
* [[Component_Model#Desugaring | Desugaring]] -- explain appearance and behavior of controls in terms of CSS/DOM. | |||
|} | |||
== | ==Media Controls For The Video Element== | ||
Using DOM elements, build a media controls panel for the [http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html#the-video-element video element]. The media controls include: | |||
* timeline slider | |||
* stop/start, replay, closed-captioning, forward, rewind and volume buttons, and | |||
* a volume control, which is revealed when hovering over the volume button. | |||
The implementation details of the media controls should not be accessible or perceptible from outside of the video element. Document styles should not interfere with the styles of the media controls panel. However, we must provide a way for an author to explicitly style all parts of the media controls panel. | |||
The implementation should be | |||
== | ==Details/Summary Elements== | ||
Implement [http://www.whatwg.org/specs/web-apps/current-work/multipage/interactive-elements.html#the-details-element details] and [http://www.whatwg.org/specs/web-apps/current-work/multipage/interactive-elements.html#the-summary-element summary] elements. According to the spec, the first <code>summary</code> element found in the flow content is used to represent a summary or legend of details. In case a <code>summary</code> element is not found, the UA is supposed to auto-generate some fallback content. The <code>details</code> element itself needs to have a marker indicating whether <code>details</code> element is open or closed - i.e., whether all contents of <details> are shown, or only the summary. | |||
# | |||
Just like media controls, the implementation should not be accessible by the consumer of the elements. For example, the reordering of flow content to position <code>summary</code> element as first item in the disclosure widget should be imperceptible to DOM traversal methods. | |||
Latest revision as of 15:46, 10 November 2012
This document is obsolete.
For more information, see: http://www.w3.org/2008/webapps/wiki/Component_Model_Use_Cases
These use cases represent a set of problems we are trying to solve by implementing a component model for the web.
Custom Controls
Current practice for sizable web applications is to use JavaScript libraries to provide a system to support the construction of custom controls. Implementing these controls can be made simpler and more interoperable with runtime support.
Layout Manager
Who | Web Framework Engineer |
---|---|
What | Build a layout library, consisting of a UI layout primitives, such as panel, resizeable panel, tab group, stack, accordion containers, etc. |
Purpose |
|
Examples | |
Desirable Properties |
|
Widget Mix-and-Match
Who | Web Application Engineer |
---|---|
What | Build an application using multiple existing controls from several frameworks. |
Purpose |
|
Examples | |
Desirable Properties |
|
Rendering Form Controls with SVG
Who | Web Application Engineer or Web Framework Engineer |
---|---|
What | Create a set of UI controls that act like standard HTML forms controls, but use SVG for rendering. |
Purpose |
|
Examples |
SproutCore's ImageButtonView, Sencha's Number -- examples of extensive themed form control hierarchy. |
Desirable Properties |
|
Contacts Widget
Who | Web Application Engineer |
---|---|
What | Build a drop-in Contacts widget, which has a pre-defined appearance and shows a list of your contacts, with a way to change the widget to compact or full view and to tell the widget to refresh its state. |
Purpose |
|
Examples | A screenshot of Google+ "in your circles" widget |
Desirable Properties |
|
Like/+1 Button
Who | Web Application Engineer |
---|---|
What | Build a drop-in widget with a pre-defined appearance of a button, showing a count of likes/+1s for this instance of a button (count is stored at a central location), embeddable on any document on the Web. |
Purpose |
|
Examples | |
Desirable Properties |
|
Table-based Charts
Who | Web Framework Engineer |
---|---|
What | Provide a way to represent table data markup as charts or diagrams. |
Purpose | Make it easy for Web authors to create charts and diagrams using table markup. |
Examples | |
Desirable Properties |
|
Timezone selection via Image
Who | Web Framework Engineer |
---|---|
What | Graphical representation of a timezone selector that shows a world map in addition to/instead of a drop-down list. |
Purpose | Make it easy for Web authors to spruce up time zone selection (or similar). |
Examples | |
Desirable Properties |
|
Entry-helper
Who | Web Framework Engineer, Web Application Engineer |
---|---|
What | Add an entry-helper (drop-down) list to input fields. |
Purpose |
Help the user fill in a form field, show suggestions and acceptable values, speed up data entry. |
Examples |
|
Desirable Properties |
|
Built-in HTML Elements
Many non-trivial (i.e. with additional behavior and styling beyond the standard box model) elements that exist in HTML today could be implemented using HTML/CSS/JS. It makes sense to provide a standardized way to accomplish this, with the short-term goals of reducing the size of browsers C++ code and making new element implementation easier, and the long-term goal of converging built-in HTML element implementations across browsers.
Who | Browser Engineer |
---|---|
What | Implement a built-in HTML element by composing or extending existing HTML elements |
Purpose |
|
Desirable Properties |
|
Media Controls For The Video Element
Using DOM elements, build a media controls panel for the video element. The media controls include:
- timeline slider
- stop/start, replay, closed-captioning, forward, rewind and volume buttons, and
- a volume control, which is revealed when hovering over the volume button.
The implementation details of the media controls should not be accessible or perceptible from outside of the video element. Document styles should not interfere with the styles of the media controls panel. However, we must provide a way for an author to explicitly style all parts of the media controls panel.
Details/Summary Elements
Implement details and summary elements. According to the spec, the first summary
element found in the flow content is used to represent a summary or legend of details. In case a summary
element is not found, the UA is supposed to auto-generate some fallback content. The details
element itself needs to have a marker indicating whether details
element is open or closed - i.e., whether all contents of <details> are shown, or only the summary.
Just like media controls, the implementation should not be accessible by the consumer of the elements. For example, the reordering of flow content to position summary
element as first item in the disclosure widget should be imperceptible to DOM traversal methods.