How to Use El for External CSS Files with Jsf

Can I use EL for external CSS files with JSF?

I put the CSS images always in a subfolder of the CSS folder. E.g.

/resources/css/style.css
/resources/css/images/example.jpg

This way you just end up like

.someId { background-image:url(images/example.jpg); }

Yes, they are resolved relative to the URL of the CSS file itself, not to the main JSF/HTML page.

Background url path in a jsf template

CSS background images are loaded relative to the request URL of the CSS file (and thus not immediately relative to its physical location in the web content). If you explore the generated HTML output of the <h:outputStylesheet>, then you'll see that the request URL has become different. Assuming a context path of /somecontext and a FacesServlet mapping of *.xhtml, it'll look like this:

<link rel="stylesheet" type="text/css" href="/somecontext/javax.faces.resource/cssLayout.css.xhtml?ln=css" />

Note that your (improper btw) usage of the library has moved the /css to ?ln=css. You'd need to fix the background image url() accordingly so that it's properly relative to the real request URL of the CSS. E.g.

background-image: url("../resources/css/imgSite/sisLogo.png");

A more reliable way, which takes JSF resource identifier rules and FacesServlet mapping into account, is to use #{resource} in EL:

background-image: url("#{resource['css:imgSite/sisLogo.png']}");

How to reference CSS / JS / image resource in Facelets template?

Introduction

The proper JSF 2.x way is using <h:outputStylesheet>, <h:outputScript> and <h:graphicImage> with a name referring the path relative to webapp's /resources folder. This way you don't need to worry about the context path as you would do in JSF 1.x. See also How to include CSS relative to context path in JSF 1.x?

Folder structure

Drop the CSS/JS/image files in /resources folder of the public webcontent as below (just create one if not already exist at the same level as /WEB-INF and /META-INF).

WebContent
 |-- resources
 |    |-- css
 |    |    |-- other.css
 |    |    `-- style.css
 |    |-- js
 |    |    `-- script.js
 |    `-- images
 |         |-- background.png
 |         |-- favicon.ico
 |         `-- logo.png
 |-- META-INF
 |    `-- MANIFEST.MF
 |-- WEB-INF
 |    |-- faces-config.xml
 |    `-- web.xml
 |-- page.xhtml
 :

In case of Maven, it should be in /main/webapp/resources and thus not /main/resources (those are for Java resources (properties/xml/text/config files) which must end up in runtime classpath, not in webcontent). See also Maven and JSF webapp structure, where exactly to put JSF resources.

Referencing in Facelets

Ultimately, those resources are available as below everywhere without the need to fiddle with relative paths:

<h:head>
    ...
    <h:outputStylesheet name="css/style.css" />
    <h:outputScript name="js/script.js" />
</h:head>
<h:body>
    ...
    <h:graphicImage name="images/logo.png" />
    ...
</h:body>

The name attribute must represent the full path relative to the /resources folder. It does not need to start with /. You do not need the library attribute as long as you aren't developing a component library like PrimeFaces or a common module JAR file which is shared by multiple webapps.

You can reference the <h:outputStylesheet> anywhere, also in <ui:define> of template clients without the need for an additional <h:head>. It will via the <h:head> component of master template automatically end up in generated <head>.

<ui:define name="...">
    <h:outputStylesheet name="css/style.css" />
    ...
</ui:define>

You can reference <h:outputScript> also anywhere, but it will by default end up in the HTML exactly there where you declared it. If you want it to end up in <head> via <h:head>, then add target="head" attribute.

<ui:define name="...">
    <h:outputScript name="js/script.js" target="head" />
    ...
</ui:define>

Or, if you want it to end up at the end of <body> (right before </body>, so that e.g. window.onload and $(document).ready() etc isn't necessary) via <h:body>, then add target="body" attribute.

<ui:define name="...">
    <h:outputScript name="js/script.js" target="body" />
    ...
</ui:define>

PrimeFaces `HeadRenderer`

In case you're using PrimeFaces, its HeadRenderer will messup the default <h:head> script ordering as described above. You're basically forced to force the order via PrimeFaces-specific <f:facet name="first|middle|last">, which may end up in messy and "untemplateable" code. You may want to turn off it as described in this answer.

Packaging in JAR

You can even package the resources in a JAR file. See also Structure for multiple JSF projects with shared code.

Referencing in EL

You can in EL use the #{resource} mapping to let JSF basically print a resource URL like /context/javax.faces.resource/folder/file.ext.xhtml?ln=library so that you could use it as e.g. CSS background image or favicon. Only requirement is that the CSS file itself should also be served as a JSF resource, otherwise EL expressions won't evaluate. See also How to reference JSF image resource as CSS background image url.

.some {
    background-image: url("#{resource['images/background.png']}");
}

Here's the @import example.

@import url("#{resource['css/other.css']}");

Here's the favicon example. See also Add favicon to JSF project and reference it in <link>.

<link rel="shortcut icon" href="#{resource['images/favicon.ico']}" />

In case you're using a SCSS compiler (e.g. Sass Compiler Plugin for Maven), keep in mind that the SCSS processor might interpret # as a special character. In that case you would need to escape it with \.

.some {
    background-image: url("\#{resource['images/background.png']}");
}

Referencing third-party CSS files

Third party CSS files loaded via <h:outputStylesheet> which in turn reference fonts and/or images may need to be altered to use #{resource} expressions as described in previous section, otherwise an UnmappedResourceHandler needs to be installed in order to be able to serve those using JSF. See also a.o. Bootsfaces page shows up in browser without any styling and How to use Font Awesome 4.x CSS file with JSF? Browser can't find font files.

Hiding in /WEB-INF

If you intend to hide the resources from public access by moving the whole /resources folder into /WEB-INF, then you can since JSF 2.2 optionally change the webcontent-relative path via a new web.xml context parameter as follows:

<context-param>
    <param-name>javax.faces.WEBAPP_RESOURCES_DIRECTORY</param-name>
    <param-value>/WEB-INF/resources</param-value>
</context-param>

In older JSF versions this is not possible.

Can't link to images from CSS in JSF

You can use el expressions in your css as long as your WAR structure includes the resources folder under which you have your css folder. See my answer here.

In short, this:

.someClass {
    background-image: url('#{resource['images/image1.png']}');
}

Or something similar

JSF Navigation with Different CSS Class for Current/Active Path

You can use #{request.requestURI} to get the current request URI. You can if necessary use several EL functions from JSTL fn taglib to do some string comparisons/manipulations in EL.

Your proposed EL styleClass suggestion is perfectly fine. There is no other easy way anyway. Best optimization which you could do so far is to render those links in a loop by an <ui:repeat> so that code duplication is at least eliminated.

How can I embed an CSS background image link with JSF?

If I correctly understood your question:

In my project I've used this style:

<h1
 class="logo"
 style="background:url( #{mainMenuNavigationBean.headerImage} ) no-repeat;">

where mainMenuNavigationBean is a session bean where I set the headerImage based on some conditions.

Changing JSF prefix to suffix mapping forces me to reapply the mapping on CSS background images

and then I see that everything going through FacesServlet has .xhtml appended to it, so that the browser is requesting .png.xhtml files, .css.xhtml file - is this right?

This only applies to resources included by <h:outputStylesheet> and <h:outputScript>. This is not related to the change in the URL mapping. This is related to the change from JSF 1.x to JSF 2.x and the change from <link rel="stylesheet"> and <script> to the aforementioned JSF2 tags.

For your own scripts, stylesheets and other static stuff which is to be served from the public webcontent, you should not manually add the .xhtml extension. You should not need to change anything with regard to existing static resources.

Only for CSS background images and other url() references in CSS files which is to be included using the <h:outputStylesheet> tag (and thus not for <link rel="stylesheet>), you would need to change the url() location to be dynamically resolved by EL. You would need to use the following syntax instead:

body {
    background-image: url("#{resource['libraryname:path/to/image.png']}");
}

Imagine that you have the following /resources folder structure:

WebContent
 |-- META-INF
 |-- resources
 |    `-- default
 |         |-- images
 |         |    `-- background.png
 |         `-- css
 |              `-- style.css
 |-- WEB-INF
 `-- test.xhtml

and that you're including the style.css in test.xhtml as follows

<h:outputStylesheet library="default" name="css/style.css" />

then you should be defining the background image URL as follows

body {
    background-image: url("#{resource['default:images/background.png']}");
}

Or when you're relying on the default library, thus you aren't using the library, then it should rather look like this:

WebContent
 |-- META-INF
 |-- resources
 |    |-- images
 |    |    `-- background.png
 |    `-- css
 |         `-- style.css
 |-- WEB-INF
 `-- test.xhtml

test.xhtml:

<h:outputStylesheet name="css/style.css" />

style.css:

body {
    background-image: url("#{resource['images/background.png']}");
}

As to the securiry constraint, it is not needed when you're already using the *.xhtml mapping. The security constraint is intended to prevent the enduser from seeing the raw XHTML source code when the FacesServlet is mapped on a pattern other then *.xhtml. The enduser would be able to see the XHTML source code by just removing /faces part from the URL in case of a /faces/* mapping or renaming .jsf to .xhtml in case of a *.jsf mapping. Get rid of the security constraint, it makes in your case things worse as you're already using a *.xhtml mapping which makes it already impossible to see the raw XHTML source code by hacking the URL.

How to Use El for External CSS Files with Jsf

Can I use EL for external CSS files with JSF?

Background url path in a jsf template

See also:

How to reference CSS / JS / image resource in Facelets template?

Introduction

Folder structure

Referencing in Facelets

PrimeFaces `HeadRenderer`

Packaging in JAR

Referencing in EL

Referencing third-party CSS files

Hiding in /WEB-INF

See also:

Can't link to images from CSS in JSF

JSF Navigation with Different CSS Class for Current/Active Path

How can I embed an CSS background image link with JSF?

Changing JSF prefix to suffix mapping forces me to reapply the mapping on CSS background images

Related Topics

Leave a reply

Can I use EL for external CSS files with JSF?

Background url path in a jsf template

See also:

How to reference CSS / JS / image resource in Facelets template?

Introduction

Folder structure

Referencing in Facelets

PrimeFaces HeadRenderer

Packaging in JAR

Referencing in EL

Referencing third-party CSS files

Hiding in /WEB-INF

See also:

Can't link to images from CSS in JSF

JSF Navigation with Different CSS Class for Current/Active Path

How can I embed an CSS background image link with JSF?

Changing JSF prefix to suffix mapping forces me to reapply the mapping on CSS background images

Related Topics

Leave a reply

PrimeFaces `HeadRenderer`