RESTful is well known and established archetecture. It does not need our approvals or recomendations.
It's something different that we want to express. We'd like to thank all those people who formulated those ideas.
While one can argue that REST has "always" existed along with the web, from our experience we can see that most of web applications we have created up to the late 200x were stateful.
We can see that many web applications should support the application (session) state. And here REST has given a rule:
client stores a session state;
server does not store a session, and is represented as set of services;
if there is a state that cannot be stored on a client (e.g. due to security reasons), then server should use caches, and be able to reconstruct that state upon cache miss.
Now is a good time for the proliferation of the REST, as even weakest clients (browsers) can implement its requirements.
REST allowed us to drastically simplify development and support, to unload server, and to build better web applications.
We compare web applications we have written a decade ago using ASP.NET, and in last 3-4 years using RESTful ideas both in java and in .NET. Clearly, the later have better performance, but from the support standpoint the most appealing is that you can instantly upgrade the application without impacting users, as there are no sessions on the server. For the same reason you should not puzzle over whether you should use in-process sessions and session stickness with load balancing server, or out-of-process sessions.
Things became simpler:
server now is pure logic through services (WCF, Web API, JAX-RS);
client is gui - jquery, kendoui or other;
aspx/jsf pages gone completely;
Earlier, in the article How To: Load KendoUI Templates from External Files, we were talking about the way to combine project's templates into a single file using Text Templates. Now, we would like to suggest the next step.
KendoUI defines text templates that it knows to transform into functions, at runtime obviously. Thus a template like this:
<td data-bind=" text: name"></td>
<td>#: kendo.toString(get("price"), "C") #</td>
<td data-bind="text: unitsInStock"></td>
<td><button class="k-button" data-bind="click: deleteProduct"> Delete</button></td>
is transformed into a function:
o='<tr><td data-bind="text: name"></td><td>'+
e( kendo.toString(get("price"), "C") )+
'</td><td data-bind="text: unitsInStock"></td>' +
'<td><button class="k-button" ' +
The transformation is done through a sequence of of regex replaces.
Right! That, which does not work at runtime.
What we thought is that we can generate those functions at compile time rather than defining templates.
<base href="/" />
<link href="styles/kendo.common.min.css" rel="stylesheet" />
<link href="styles/kendo.default.min.css" rel="stylesheet" />
<td>Products count: #: total() #</td>
<td>Total price: #: totalPrice() #</td>
<td colspan="2">Units in stock: #: totalUnitsInStock() #</td>
templates.js will look like this:
document.write('<script id="footer-view-template" type="text/x-kendo-template">#=nesterovskyBros.templates["footer-view"](data)#</script>');
To get template function at runtime you simply refer to
template.tt now allows you to specify:
data-scriptattribute over each template (default is
true) to prevent generation of
data-with-blockattribute (default is
true) to prevent
See a sample application that shows how nicely KendoUI UserControls work with those compiled templates.
Awhile ago we have created a set of xml schemas and xslt to represent different languages as xml, and to generate source from those xmls. This way we know to represent and generate: java, c#, cobol, and several sql dialects (read about languages xom on this site).
Here, we'd like to expose a nuisance we had with sql dialects schema.
Our goal was to define a basic sql schema, and dialect extensions. This way we assumed to express general and dialect specific constructs. So, lets consider an example.
-- Select one row
select * from A
select * from A fetch first row only
select top 1 * from A
select * from A where rownum = 1
All these queries have common core syntax, while at the same time have dialect specific means to express intention to return first row only.
Down to the xml schema basic select statement looks like this:
<xs:element name="columns" type="columns-clause">
<xs:element name="from" type="from-clause" minOccurs="0">
<xs:element name="where" type="unary-expression" minOccurs="0"/>
<xs:element name="group-by" type="expression-list" minOccurs="0"/>
<xs:element name="having" type="unary-expression" minOccurs="0"/>
<xs:element name="order-by" type="order-by-clause" minOccurs="0"/>
<xs:attribute name="specification" type="query-specification"
Here all is relatively clear. The generic select looks like:
But how would you define dialect specifics?
E.g. for T-SQL we would like to see a markup:
While for DB2 there should be:
So, again the quesions are:
Though we have tried several solutions to that problem, none is satisfactory enough.
To allow extensions we have defined that all elements in sql schema are based on
sql-element, which allows extensions:
<xs:complexType name="sql-element" abstract="true">
<xs:element ref="extension" minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="extension" type="extension"/>
<xs:complexType name="extension" abstract="true">
<xs:element name="top" type="top-extension" substitutionGroup="sql:extension"/>
<xs:attribute name="percent" type="xs:boolean" use="optional" default="false"/>
Unfortunately, this creates too weak typed schema for extensions, thus intellisence suggests too many options.
On a way to a home we usually listen audio books in our car. In most cases these are science fiction stories. One of our favorite authors is Ray Bradbury. Probably you know his short story collection "The Martian Chronicles". Also, we like to glance over technology and science news to stay tuned in the latest innovations.
Recently, we've read an article that states that NASA is going to send a group of scientists-colonists to Mars in an observable future. It sounds in Ray Bradbury style.
Although, we're not specialists in this field, we discussed what difficulties may face such an expedition.
As far as we understand, there are following issues that must be solved before expedition may start:
speed of a spaceship is yet too slow
a shield from radiation doesn't exist
big cargo section to contain sufficient reserve of water, food and oxygen for the expedition to survive
a way to produce enough energy to survive on Mars
Actually, the second issue depends on the first one. At present there is no reliable long term protection from cosmic radiation, which can be installed on a spacecraft. At least we didn't hear about such thing. Thus, long staying in the open space will seriously harm colonists and may bring to naught the whole mission.
Сonsidering these facts, we concluded that a space travel further than the moon is not possible at present.
What could be done to solve these issues?
As a solution of space colonization could be the following. The earthlings won't send people but robots with corresponding equipment and containers for man, animals and plants DNAs or embryos. At the destination place robots will build a colony and will begin to grow people, animals, plants; to train them and to serve them later (at least to man " src="http://www.nesterovsky-bros.com/weblog/smilies/wink.gif"/> ).
How all this may solve the mentioned issues?
It's much easier to create reliable shield from radiation for small DNA or embrios containers.
time and speed of a spacecraft, in such case, will impact less on the mission.
weight of spacecraft in this case could be less, or it may get more payload.
Thus, to bring the era of cosmic expansion, human kind must invest in the development of robotics, artificial intelligence, genetic engineering, development of rapid learning, among other scientific fields in space exploration.
Right now, you may see a beginning? of this trend in sciense here DFKI's robot ape to colonize the Moon?
In the far future, after the beginning will be forgotten, all this may lead to question: who was the first a man or a robot? " src="http://www.nesterovsky-bros.com/weblog/smilies/wink.gif"/>
While developing with KendoUI we have found
toggle) function to be
very useful. It's used to show or hide a progress indicator
in the container element.
At the same time we have found that we usually used it in a context of async operation. This way, we want to show progress, perform some asynchronous operations, hide progress. So, we clearly want to benifit from RAII pattern: we would like to open a progress scope, and to perform some activity withing this scope.
Arguing like this, we have defined a utility function, which is the fusion of
$.when(). Its signature is
nesterovskyBros.progress = function(instance /*, task ... */)
instance is either
JQuery or DOM
task is one or more deferred objects. This function shows a progress
and returns a
Promise that will hide a progress when all tasks will be complete.
Implementation is trivial, so we quote it here:
// Fusion of kendo.ui.progress() and $.when().
scope.progress = function(instance /*, task ... */)
if (instance instanceof Model)
instance = instance.owner && instance.owner();
if (instance instanceof Widget)
instance = instance.element;
if (instance && instance.nodeType)
instance = $(instance);
var id = ns + "-progress"; // "nesterovskyBros-progress";
var progress = (instance && instance.data(id)) || 0;
if (arguments.length < 2)
var result = $.when.apply(null, .slice.call(arguments, 1));
kendo.ui.progress(instance, progress > 0);
progress = instance.data(id) || 0;
kendo.ui.progress(instance, progress > 0);
The use is like this:
nesterovskyBros.progress(element, $.ajax("/service1"), $.ajax("/service2")).then(myFunc);
The code can be found at controls.js.
At present we have defined:
1. An extended model. See KendoUI extended model.
2. A lightweight user control - a widget to bind a template and a model, and to facilitate declarative instantiation. See KendoUI User control.
3. A reworked version of nesterovskyBros.defineControl() function.
var widgetType = scope.defineControl(
optional-content-template is not specified then template is
calculated as following:
var template = options.temlate || proto.template || model.temlate;
if (template === undefined)
template = scope.template(options.name.toLowerCase() + "-template");
windowOptions is specified then
widgetType.dialog(options) function is defined. It's used to open dialog based on
the specified user control.
windowOptions is passed to
windowOptions.closeOnEscape indicates whether to close opened dialog on escape.
widgetType.dialog() returns a
kendo.ui.Window instance with content based on the
user control. Window instance contains functions:
$.Defferedfor the dialog result, and
model()- referring to the user control model.
The model instance has functions:
dialog()referring to the dialog, and
result()referring to the dialog result.
widget.dialog() allows all css units in
base - is optional user control base. It defaults to
4. Adjusted splitter. See Adjust KendoUI Splitter.
5. Auto resize support.
Layout is often depends on available area. One example is
Splitter widget that
recalculates its panes when window or container
Splitter is resized.
There are other cases when you would like to adjust layout when a container's
area is changed like: adjust grid, tab, editor or user's control contents.
KendoUI does not provide a solution for this problem, so we have defined our own.
widgetType.autoResize(element)function that adapts widget to a new size.
nesterovskyBros.resize(element)function at trigger resizing of the subtree.
To support existing controls we have defined
autoResize() function for
Please note that we consider controls.js as an addition to KendoUI library. If in the future the library will integrate or implement similar features we will be happy to start using their API.
See also: Compile KendoUI templates.