This helps your architect and developer to work on the identical same template file and reduce the feat required to transform a static prototype into a bring template file. The ability to do this is a feature of speech called Natural Templating. not alone will this be correctly displayed by browsers, but this besides allow us to ( optionally ) specify a value attribute in it ( “ James Carrot ”, in this character ) that will be displayed when the prototype is statically opened in a browser, and that will be substituted by the value resulting from the evaluation of $ { user.name } during work of the template. …the Thymeleaf Standard Dialect would allow us to achieve the same functionality with : Most of the processors of the Standard Dialect are assign processors. This allows browsers to correctly display HTML template files evening before being processed because they will merely ignore the extra attributes. For case, while a JSP using tag libraries could include a shard of code not directly displayable by a browser like :

The official thymeleaf-spring3 and thymeleaf-spring4 integration packages both define a dialect called the “ SpringStandard Dialect ”, which is largely the like as the Standard Dialect, but with little adaptations to make better use of some features in the jump Framework ( for case, by using Spring Expression Language or SpringEL rather of OGNL ). so if you are a Spring MVC user you are not wasting your prison term, as about everything you learn here will be of use in your leap applications. Of run, users can create their own dialects ( even extending the Standard one ) if they want to define their own process logic while taking advantage of the library ’ s advanced features. Thymeleaf can besides be configured to use several dialects at a time. This tutorial covers the Standard Dialect. Every property and syntax have you will learn about in the stick to pages is defined by this dialect, even if that isn ’ deoxythymidine monophosphate explicitly mentioned. note that dialects can actually have no processors and be entirely comprised of other kinds of artifacts, but processors are decidedly the most common use lawsuit. An object that applies some logic to a markup artifact ( a rag, some text, a gloss, or a bare placeholder if templates are not markup ) is called a processor, and a set of these processors – plus possibly some extra artifacts – is what a dialect is normally comprised of. Out of the box, Thymeleaf ’ s effect library provides a dialect called the Standard Dialect, which should be enough for most users. Thymeleaf is an highly extensile template locomotive ( in fact it could be called a template engine framework ) that allows you to define and customize the manner your templates will be processed to a very well level of detail. The RAW template modality will merely not process templates at all. It is meant to be used for inserting untouched resources ( files, URL responses, etc. ) into the templates being processed. For model, external, uncontrolled resources in HTML format could be included into application templates, safely knowing that any Thymeleaf code that these resources might include will not be executed. The CSS template mode will allow the action of CSS files involved in a Thymeleaf lotion. similar to the JAVASCRIPT modality, the CSS template mood is besides a textual mode and uses the special process syntax from the TEXT template manner. The JAVASCRIPT template mode will allow the process of JavaScript files in a Thymeleaf application. This means being able to use model data inside JavaScript files in the lapp way it can be done in HTML files, but with JavaScript-specific integrations such as specialize elude or natural script. The JAVASCRIPT template mode is considered a textual modality and consequently uses the same especial syntax as the TEXT template mode. The TEXT template modality will allow the use of a particular syntax for templates of a non-markup nature. Examples of such templates might be text emails or templated documentation. note that HTML or XML templates can be besides processed as TEXT, in which case they will not be parsed as markup, and every chase, DOCTYPE, comment, etc, will be treated as mere text. The XML template modality will allow XML input signal. In this case, code is expected to be grammatical – no unclosed tags, no unquoted attributes, etc – and the parser will throw exceptions if well-formedness violations are found. eminence that no validation ( against a DTD or XML Schema ) will be performed. The HTML template mood will allow any kind of HTML stimulation, including HTML5, HTML 4 and XHTML. No establishment or well-formedness check will be performed, and template code/structure will be respected to the biggest possible extent in output. There are two markup template modes ( HTML and XML ), three textual template modes ( TEXT, JAVASCRIPT and CSS ) and a no-op template modality ( RAW ). Out-of-the-box, Thymeleaf allows you to process six kinds of templates, each of which is called a Template Mode : Thymeleaf has besides been designed from the beginning with Web Standards in mind – specially HTML5 – allowing you to create fully validating templates if that is a indigence for you. The independent goal of Thymeleaf is to provide an elegant and highly-maintainable means of creating templates. To achieve this, it builds on the concept of Natural Templates to inject its logic into template files in a manner that doesn ’ metric ton affect the template from being used as a design prototype. This improves communication of plan and bridges the gap between design and development teams. Thymeleaf is a mod server-side Java template engine for both web and standalone environments, capable of processing HTML, XML, JavaScript, CSS and even plain textbook. Our Template Engine is now ready and we can start creating our pages using Thymeleaf. A template resolver is the only ask argument a TemplateEngine needs, although there are many others that will be covered subsequently ( message resolvers, hoard sizes, etc ). For now, this is all we need. rather childlike, international relations and security network ’ metric ton it ? All we need is to create an case and set the Template Resolver to it. Template Engine objects are implementations of the org.thymeleaf.ITemplateEngine interface. One of these implementations is offered by the Thymeleaf core : org.thymeleaf.TemplateEngine, and we create an example of it here : There is much more to learn about template resolvers, but for now let ’ s have a look at the universe of our Template Engine object. Cache behavior and sizes can be defined by the user by implementing the ICacheManager interface or by modifying the StandardCacheManager object to manage the default option hoard. A template can placid be expelled from hoard before that TTL is reached if the soap cache size is reached and it is the oldest introduction presently cached. optionally, the amount of time that a parse template can live in the hoard is configured at the Template Resolver by means of the cacheTTLMs property : Using this configuration, the template identify “ product/list ” would correspond to : The prefix and suffix modify the template names that we will be passing to the engine for obtaining the real resource names to be used. HTML is the default template mode for ServletContextTemplateResolver, but it is good drill to establish it anyhow so that our code documents clearly what is going on. But that ’ s not all we can say about the template resolver, because we can set some configuration parameters on it. First, the template mood : These objects are in charge of determining how our templates will be accessed, and in this GTVG application, the org.thymeleaf.templateresolver.ServletContextTemplateResolver means that we are going to retrieve our template files as resources from the Servlet Context : an application-wide javax.servlet.ServletContext object that exists in every Java vane lotion, and that resolves resources from the vane application root. template Resolvers are objects that implement an interface from the Thymeleaf API called org.thymeleaf.templateresolver.ITemplateResolver : There are many ways of configuring a TemplateEngine object, but for now these few lines of code will teach us enough about the steps needed. Our org.thymeleaf.TemplateEngine object is initialized like this : Which means that the GTVGApplication classify is in charge of creating and configuring one of the most authoritative objects in a Thymeleaf application : the TemplateEngine case ( implementation of the ITemplateEngine interface ). The procedure ( … ) method in our filter contained this line : But first lashkar-e-taiba ’ s see how that template engine is initialized. In the end, it will look like this : All we have to do now is create implementations of the IGTVGController interface, retrieving data from the services and processing templates using the ITemplateEngine object. At the network layer our lotion will have a trickle that will delegate execution to Thymeleaf-enabled commands depending on the request url : Our application will besides have a very elementary service layer, composed by Service objects containing methods like : To start, we need a bare fructify of model entities for our application : Products which are sold to Customers by creating Orders. We will besides be managing Comments about those Products : This application is the vane locate of an fanciful virtual grocery store, and will provide us with many scenarios to showcase Thymeleaf ’ s many features. To better explain the concepts involved in processing templates with Thymeleaf, this tutorial will use a demonstration application which you can download from the stick out ’ s world wide web locate. The source code for the examples shown in this, and future chapters of this guide, can be found in the well Thymes Virtual Grocery GitHub depository. There are quite a set of possibilities in property values : messages, variable expressions… and quite a lot more. The next chapter will show us what all these possibilities are. The $ { today } construction simply means “ get the variable called nowadays ”, but these expressions could be more building complex ( like $ { user.name } for “ get the variable called exploiter, and call its getName ( ) method acting ” ). As you can see, we are still using the thorium : textbook impute for the job ( and that ’ sulfur correct, because we want to replace the tag ’ s soundbox ), but the syntax is a little piece different this fourth dimension and alternatively of a # { … } construction value, we are using a $ { … } one. This is a variable saying, and it contains an expression in a language called OGNL ( Object-Graph Navigation Language ) that will be executed on the context variables map we talked about before. We have added a String variable called today to our context, and now we can display it in our template : First of wholly, we will have to modify our restrainer so that we add that go steady as a context variable : nowadays let ’ s add some more content to our home page. For model, we may want to display the date below our welcome message, like this : This will end product our message equitable like we wanted it : This is the default behavior of the thorium : text attribute. If we want Thymeleaf to respect our HTML tag and not escape them, we will have to use a different assign : thorium : utext ( for “ unescaped text ” ) : Which is not precisely what we expected, because our tag has been escaped and therefore it will be displayed in the browser. If we execute this template like ahead, we will obtain : The simplest adaptation of our Home page seems to be quick now, but there is something we have not thought about… what if we had a message like this ? Let ’ s see the results of this using the spanish venue : With our context object ready, now we can tell the template engine to process the template ( by its name ) using the context, and passing it a response writer so that the response can be written to it : There are some specialized expressions that we will be able to use to obtain the request parameters and the request, session and application attributes from the WebContext in our templates. For exercise : only three out of those four builder arguments are required because the default venue for the system will be used if none is specified ( although you should never let this happen in real applications ). And as you can see in the control code, WebContext is the one we use. In fact we have to, because the consumption of a ServletContextTemplateResolver requires that we use a context implementing IWebContext. The Thymeleaf effect library offers an implementation of each of these interfaces : There is a speciate extension of this interface, org.thymeleaf.context.IWebContext, entail to be used in ServletAPI-based world wide web applications ( like SpringMVC ). The foremost thing we see is the creation of a context. A Thymeleaf context is an object implementing the org.thymeleaf.context.IContext interface. Contexts should contain all the data required for an execution of the template locomotive in a variables map, and besides reference the venue that must be used for project messages. In order to process our template, we will create a HomeController class implementing the IGTVGController interface we saw before : This is all we need for making Thymeleaf process our template. Let ’ s create our Home accountant then. Let ’ s have a look at our home_es.properties file : The standard message resolver expects to find messages for /WEB-INF/templates/home.html in properties files in the same booklet and with the same mention as the template, like : however, we have not specified a message resolver for our template engine during low-level formatting, and that means that our application is using the Standard Message Resolver, implemented by org.thymeleaf.messageresolver.StandardMessageResolver. The placement of project text in Thymeleaf is amply configurable, and it will depend on the specific org.thymeleaf.messageresolver.IMessageResolver implementation being used. normally, an implementation based on .properties files will be used, but we could create our own implementations if we wanted, for exemplar, to obtain messages from a database. now, where is this exteriorize text ? What we can see here are in fact two different features of the Thymeleaf Standard Dialect : Messages constantly have a key that identifies them, and Thymeleaf allows you to specify that a text should correspond to a specific message with the # { … } syntax : Externalizing text is extracting fragments of template code out of template files so that they can be kept in offprint files ( typically .properties files ) and that they can be easily replaced with equivalent texts written in other languages ( a work called internationalization or plainly i18n ). exteriorize fragments of text are normally called “ messages ”. Both notations are wholly equivalent and exchangeable, but for the sake of simplicity and concentration of the code samples, this tutorial will use the namespace notation ( thorium : * ). besides, the thursday : * notation is more general and allowed in every Thymeleaf template mode ( XML, TEXT … ) whereas the data- note is merely allowed in HTML mode. Custom data- prefix attributes are allowed by the HTML5 specification, so, with this code above, our template would be a valid HTML5 document. so what if we wanted to make this template HTML5-valid ? Easy : substitution to Thymeleaf ’ mho data attribute syntax, using the data- prefix for attribute names and hyphen ( – ) separators alternatively of semi-colons ( : ) : …which has no influence at all in template process, but works as an incantation that prevents our IDE from complaining about the miss of a namespace definition for all those th : * attributes. But you may besides notice that this template is not in truth a valid HTML5 document, because these non-standard attributes we are using in the thorium : * form are not allowed by the HTML5 stipulation. In fact, we are even adding an xmlns : thorium property to our tag, something absolutely non-HTML5-ish: The first gear thing you will notice is that this file is HTML5 that can be correctly displayed by any browser because it does not include any non-HTML tags ( browsers ignore all attributes they don ’ triiodothyronine sympathize, like thorium : text ). The first version of this page will be highly simple : precisely a title and a welcome message. This is our /WEB-INF/templates/home.html file : Our first gear task will be to create a home plate page for our grocery store site .

4 Standard Expression Syntax

We will take a little unwrap in the development of our grocery store virtual storehouse to learn about one of the most authoritative parts of the Thymeleaf Standard Dialect : the Thymeleaf Standard Expression syntax .
We have already seen two types of valid attribute values expressed in this syntax : message and varying expressions :

 Welcome to our grocery store shop !

 today is : 13 february 2011

But there are more types of expressions, and more interest details to learn about the ones we already know. First, let ’ s see a immediate drumhead of the Standard Expression features :

• Simple expressions:
  • Variable Expressions: ${...}
  • Selection Variable Expressions: *{...}
  • Message Expressions: #{...}
  • Link URL Expressions: @{...}
  • Fragment Expressions: ~{...}
• Literals
  • Text literals: 'one text', 'Another one!',…
  • Number literals: 0, 34, 3.0, 12.3,…
  • Boolean literals: true, false
  • Null literal: null
  • Literal tokens: one, sometext, main,…
• Text operations:
  • String concatenation: +
  • Literal substitutions: |The name is ${name}|
• Arithmetic operations:
  • Binary operators: +, -, *, /, %
  • Minus sign (unary operator): -
• Boolean operations:
  • Binary operators: and, or
  • Boolean negation (unary operator): !, not
• Comparisons and equality:
  • Comparators: >, <, >=, <= (gt, lt, ge, le)
  • Equality operators: ==, != (eq, ne)
• Conditional operators:
  • If-then: (if) ? (then)
  • If-then-else: (if) ? (then) : (else)
  • Default: (value) ?: (defaultvalue)
• Special tokens:
  • No-Operation: _

All these features can be combined and nested :

'User is of type ' + (${user.isAdmin()} ? 'Administrator' : (${user.type} ?: 'Unknown'))

4.1 Messages

As we already know, #{...} message expressions allow us to link this :

 Welcome to our grocery store storehouse !

…to this :

home.welcome=¡Bienvenido a nuestra tienda de comestibles!

But there ’ s one expression we still haven ’ thymine think of : what happens if the message textbook is not wholly electrostatic ? What if, for example, our application know who is the user visiting the locate at any moment and we wanted to greet them by name ?

 ¡Bienvenido a nuestra tienda de comestibles, John Apricot !

This means we would need to add a parameter to our message. good like this :

home.welcome=¡Bienvenido a nuestra tienda de comestibles, {0}!

Parameters are specified according to the java.text.MessageFormat standard syntax, which means you can format to numbers and dates as specified in the API department of commerce for classes in the java.text.* package .
In rate to specify a value for our parameter, and given an HTTP seance impute called user, we could have :

 Welcome to our grocery store store, Sebastian Pepper !

note that the manipulation of th:utext here means that the format message will not be escaped. This example assumes that user.name is already escaped .

respective parameters can be specified, separated by comma .
The message key itself can come from a variable :

 Welcome to our grocery store store, Sebastian Pepper !

4.2 Variables

We already mentioned that ${...} expressions are in fact OGNL ( Object-Graph Navigation Language ) expressions executed on the map of variables contained in the context .

For detailed information about OGNL syntax and features, you should read the OGNL Language Guide

Read more: Google Sheets: Getting Started with Google Sheets

In Spring MVC-enabled applications OGNL will be replaced with SpringEL, but its syntax is identical similar to that of OGNL ( actually, precisely the lapp for most common cases ) .

From OGNL ’ second syntax, we know that the expression in :

 today is : 13 february 2011 .

…is in fact equivalent to this :

ctx.getVariable("today");

But OGNL allows us to create quite more mighty expressions, and that ’ s how this :

 Welcome to our grocery store store, Sebastian Pepper !

…obtains the drug user name by executing :

((User) ctx.getVariable("session").get("user")).getName();

But getter method acting navigation is just one of OGNL ’ south features. Let ’ s see some more :

/*
 * Access to properties using the point (.). Equivalent to calling property getters.
 */
${person.father.name}

/*
 * Access to properties can also be made by using brackets ([]) and writing 
 * the name of the property as a variable or between single quotes.
 */
${person['father']['name']}

/*
 * If the object is a map, both dot and bracket syntax will be equivalent to 
 * executing a call on its get(...) method.
 */
${countriesByCode.ES}
${personsByName['Stephen Zucchini'].age}

/*
 * Indexed access to arrays or collections is also performed with brackets, 
 * writing the index without quotes.
 */
${personsArray[0].name}

/*
 * Methods can be called, even with arguments.
 */
${person.createCompleteName()}
${person.createCompleteNameWithSeparator('-')}

Expression Basic Objects

When evaluating OGNL expressions on the context variables, some objects are made available to expressions for higher tractability. These objects will be referenced ( per OGNL criterion ) starting with the # symbol :

• #ctx: the context object.
• #vars: the context variables.
• #locale: the context locale.
• #request: (only in Web Contexts) the HttpServletRequest object.
• #response: (only in Web Contexts) the HttpServletResponse object.
• #session: (only in Web Contexts) the HttpSession object.
• #servletContext: (only in Web Contexts) the ServletContext object.

So we can do this :

Established locale country: US.

You can read the broad reference of these objects in Appendix A .

Expression Utility Objects

Besides these basic objects, Thymeleaf will offer us a stage set of utility objects that will help us perform park tasks in our expressions .

• #execInfo: information about the template being processed.
• #messages: methods for obtaining externalized messages inside variables expressions, in the same way as they would be obtained using #{…} syntax.
• #uris: methods for escaping parts of URLs/URIs
• #conversions: methods for executing the configured conversion service (if any).
• #dates: methods for java.util.Date objects: formatting, component extraction, etc.
• #calendars: analogous to #dates, but for java.util.Calendar objects.
• #numbers: methods for formatting numeric objects.
• #strings: methods for String objects: contains, startsWith, prepending/appending, etc.
• #objects: methods for objects in general.
• #bools: methods for boolean evaluation.
• #arrays: methods for arrays.
• #lists: methods for lists.
• #sets: methods for sets.
• #maps: methods for maps.
• #aggregates: methods for creating aggregates on arrays or collections.
• #ids: methods for dealing with id attributes that might be repeated (for example, as a result of an iteration).

You can check what functions are offered by each of these utility objects in the Appendix B .

4.3 Expressions on selections (asterisk syntax)

not only can variable expressions be written as ${...}, but besides as *{...} .
There is an significant deviation though : the star syntax evaluates expressions on selected objects rather than on the hale context. That is, arsenic long as there is no choose object, the dollar and the asterisk syntaxes do precisely the same .
And what is a selected object ? The consequence of an formulation using the th:object attribute. Let ’ s use one in our exploiter visibility ( userprofile.html ) page :

  

     mention : Sebastian .
     surname : Pepper .
     nationality : Saturn .
  

Which is precisely equivalent to :

   name : Sebastian .
   surname : Pepper .
   nationality : Saturn .

Of naturally, dollar and star syntax can be shuffle :

   name : Sebastian .
   surname : Pepper .
   nationality : Saturn .

When an object excerpt is in place, the selected object will besides be available to dollar expressions as the #object expression variable star :

   name : Sebastian .
   surname : Pepper .
   nationality : Saturn .

As said, if no object choice has been performed, dollar and asterisk syntaxes are equivalent .

   name : Sebastian .
   surname : Pepper .
   nationality : Saturn .

4.4 Link URLs

Because of their importance, URLs are excellent citizens in web application templates, and the Thymeleaf Standard Dialect has a particular syntax for them, the @ syntax : @{...}
There are unlike types of url :

• Absolute URLs: http://www.thymeleaf.org
• Relative URLs, which can be:
  • Page-relative: user/login.html
  • Context-relative: /itemdetails?id=3 (context name in server will be added automatically)
  • Server-relative: ~/billing/processInvoice (allows calling URLs in another context (= application) in the same server.
  • Protocol-relative URLs: //code.jquery.com/jquery-2.0.3.min.js

The actual march of these expressions and their conversion to the URLs that will be end product is done by implementations of the org.thymeleaf.linkbuilder.ILinkBuilder interface that are registered into the ITemplateEngine object being used .
By default, a one implementation of this interface is registered of the class org.thymeleaf.linkbuilder.StandardLinkBuilder, which is enough for both offline ( non-web ) and besides web scenarios based on the Servlet API. other scenarios ( like integration with non-ServletAPI world wide web frameworks ) might need specific implementations of the connection builder interface .
Let ’ s use this new syntax. Meet the th:href assign :

view


view


view

Some things to note here :

• th:href is a modifier attribute: once processed, it will compute the link URL to be used and set that value to the href attribute of the tag.
• We are allowed to use expressions for URL parameters (as you can see in orderId=${o.id}). The required URL-parameter-encoding operations will also be automatically performed.
• If several parameters are needed, these will be separated by commas: @{/order/process(execId=${execId},execType='FAST')}
• Variable templates are also allowed in URL paths: @{/order/{orderId}/details(orderId=${orderId})}
• Relative URLs starting with / (eg: /order/details) will be automatically prefixed by the application context name.
• If cookies are not enabled or this is not yet known, a ";jsessionid=..." suffix might be added to relative URLs so that the session is preserved. This is called URL Rewriting and Thymeleaf allows you to plug in your own rewriting filters by using the response.encodeURL(...) mechanism from the Servlet API for every URL.
• The th:href attribute allows us to (optionally) have a working static href attribute in our template, so that our template links remained navigable by a browser when opened directly for prototyping purposes.

As was the case with the message syntax ( #{...} ), URL bases can besides be the resultant role of evaluating another expression :

view
view

A menu for our home page

now that we know how to create radio link URLs, what about adding a small menu in our home page for some of the early pages in the site ?

 Please select an choice

  
Product List
  
Order List
  
Subscribe to our Newsletter
  
See User Profile

Server root relative URLs

An extra syntax can be used to create server-root-relative ( alternatively of context-root-relative ) url in club to link to different context in the same waiter. These URLs will be specified like @{~/path/to/something}

4.5 Fragments

break up expressions are an easy way to represent fragments of markup and move them around templates. This allows us to replicate them, pass them to other templates as arguments, and so on .
The most common use is for shard interpolation using th:insert or th:replace ( more on these in a subsequently section ) :

...

But they can be used anywhere, fair as any other variable star :

later in this tutorial there is an integral incision devoted to Template Layout, including deeper explanation of shard expressions .

4.6 Literals

Text literals

text literals are barely character strings specified between single quotes. They can include any character, but you should escape any single quotes inside them using \' .

 now you are looking at a template file .

Number literals

numeral literals are just that : numbers .

 The class is 1492 .
 In two years, it will be 1494 .

Boolean literals

The boolean literals are true and false. For exercise :

 ...

In this example, the == false is written outside the braces, and so it is Thymeleaf that takes concern of it. If it were written inside the braces, it would be the province of the OGNL/SpringEL engines :

 ...

The null literal

The null misprint can be besides used :

 ...

Literal tokens

Numeric, boolean and null literals are in fact a particular case of literal tokens .
These tokens allow a little bit of simplification in Standard Expressions. They work precisely the same as text literals ( '...' ), but they only allow letters ( A-Z and a-z ), numbers ( 0-9 ), brackets ( [ and ] ), dots ( . ), hyphens ( - ) and underscores ( _ ). So no whitespaces, no comma, etc .
The courteous share ? Tokens wear ’ thymine need any quotes surrounding them. So we can do this :

...

alternatively of :

...

4.7 Appending texts

Texts, no topic whether they are literals or the leave of evaluating variable or message expressions, can be easily appended using the + operator :

4.8 Literal substitutions

literal substitutions allow for an easy format of strings containing values from variables without the necessitate to append literals with '...' + '...' .
These substitutions must be surrounded by vertical bars ( | ), like :

Which is equivalent to :

misprint substitutions can be combined with other types of expressions :

only variable/message expressions ( ${...}, *{...}, #{...} ) are allowed inside |...| literal substitutions. No other literals ( '...' ), boolean/numeric tokens, conditional expressions etc. are .

4.9 Arithmetic operations

Some arithmetical operations are besides available : +, -, *, / and % .

note that these operators can besides be applied inside OGNL varying expressions themselves ( and in that case will be executed by OGNL rather of the Thymeleaf Standard Expression engine ) :

note that textual aliases exist for some of these operators : div ( / ), mod ( % ) .

4.10 Comparators and Equality

Values in expressions can be compared with the >, <, >= and <= symbols, and the == and != operators can be used to check for equality ( or the miss of it ). note that XML establishes that the < and > symbols should not be used in assign values, and then they should be substituted by < and > .

A dim-witted option may be using textual aliases that exist for some of these operators : gt ( > ), lt ( < ), ge ( >= ), le ( <= ), not ( ! ). besides eq ( == ), neq / ne ( != ) .

4.11 Conditional expressions

conditional expressions are meant to evaluate only one of two expressions depending on the solution of evaluating a condition ( which is itself another expression ) .
Let ’ s have a look at an example break up ( introducing another impute modifier, th:class ) :

  ...

All three parts of a conditional expression ( condition, then and else ) are themselves expressions, which means that they can be variables ( ${...}, *{...} ), messages ( #{...} ), URLs ( @{...} ) or literals ( '...' ) .
conditional expressions can besides be nested using parentheses :

  ...

Else expressions can besides be omitted, in which case a null prize is returned if the condition is assumed :

  ...

4.12 Default expressions (Elvis operator)

A default formula is a special kind of conditional value without a then share. It is equivalent to the Elvis operator present in some languages like Groovy, lets you specify two expressions : the first one is used if it doesn ’ deoxythymidine monophosphate measure to null, but if it does then the second one is used .
Let ’ s see it in action in our user profile page :

  ...
   age : 27 .

As you can see, the operator is ?:, and we use it here to specify a default value for a mention ( a actual rate, in this encase ) lone if the result of evaluating *{age} is null. This is therefore equivalent to :

 age : 27 .

As with conditional values, they can contain nest expressions between parentheses :

 name : Sebastian

4.13 The No-Operation token

The No-Operation nominal is represented by an underscore symbol ( _ ) .
The idea behind this nominal is to specify that the craved result for an saying is to do nothing, i.e. do precisely as if the processable impute ( e.g. th:text ) was not there at all .
Among early possibilities, this allows developers to use prototyping text as default values. For exercise, rather of :

...

…we can directly use ‘ no user authenticated ’ as a prototyping text, which results in code that is both more concise and versatile from a design point of view :

no user authenticated

4.14 Data Conversion / Formatting

Thymeleaf defines a double-brace syntax for variable ( ${...} ) and choice ( *{...} ) expressions that allows us to apply data conversion by means of a configure conversion servicing .
It basically goes like this :

...

Noticed the doubly pair there ? : ${{...}}. That instructs Thymeleaf to pass the solution of the user.lastAccessDate expression to the conversion service and asks it to perform a formatting operation ( a conversion to String ) before writing the result .
Assuming that user.lastAccessDate is of character java.util.Calendar, if a conversion service ( implementation of IStandardConversionService ) has been registered and contains a valid conversion for Calendar -> String, it will be applied .
The nonpayment implementation of IStandardConversionService ( the StandardConversionService class ) just executes .toString() on any object converted to String. For more information on how to register a custom-made conversion servicing implementation, have a look at the More on Configuration section .

The official thymeleaf-spring3 and thymeleaf-spring4 consolidation packages transparently integrate Thymeleaf ’ s conversion military service mechanism with Spring ’ s own Conversion Service infrastructure, so that conversion services and formatters declared in the spring configuration will be made automatically available to ${{...}} and *{{...}} expressions .

4.15 Preprocessing

In summation to all these features for expression work, Thymeleaf has the feature of preprocessing expressions .
Preprocessing is an execution of the expressions done before the normal one that allows for modification of the formulation that will finally be executed .
Preprocessed expressions are precisely like convention ones, but appear surrounded by a bivalent underscore symbol ( like __${expression}__ ) .
Let ’ s think we have an i18n Messages_fr.properties introduction containing an OGNL expression calling a language-specific inactive method acting, like :

article.text=@flickroom.net@gmail.com({0})

…and a Messages_es.properties equivalent :

article.text=@flickroom.net@gmail.com({0})

We can create a fragment of markup that evaluates one expression or the other depending on the venue. For this, we will first select the expression ( by preprocessing ) and then let Thymeleaf execute it :

 Some textbook hera ... 
Read more: How to Use Google Forms

bill that the preprocessing mistreat for a french venue will be creating the keep up equivalent :

 Some text here ...

The preprocessing String __ can be escaped in attributes using \_\_ .

Source : https://flickroom.net
class : Web Browsers