Attribute	Description
org.osgi.service.http.authentication.remote.user	The user ID of the +JCR Session. This attribute is used by the HTTP Service implementation to +implement the HttpServletRequest.getRemoteUser method.
org.osgi.service.http.authentication.type	The authentication type +defined by the AuthenticationHandler. This attribute is used by the +HTTP Service implementation to implement the +HttpServletRequest.getAuthType method.
org.apache.sling.commons.auth.ResourceResolver	The +ResourceResolver created from the credentials and the logged in JCR +Session. This attribute may be used by servlets to access the repository. +Namely the SlingMainServlet uses this request attribute to provide the +ResourceResolver to handle the request.
javax.jcr.Session	The JCR Session. This attribute is for backwards +compatibility only. Its use is deprecated and the attribute will be +removed in future versions.
org.apache.sling.commons.auth.spi.AuthenticationInfo	The +AuthenticationInfo object produced from the AuthenticationHandler. +

Attribute

Description

*org.osgi.service.http.authentication.remote.user*

The user ID of the +JCR Session. This attribute is used by the HTTP Service implementation to +implement the *HttpServletRequest.getRemoteUser* method.

*org.osgi.service.http.authentication.type*

The authentication type +defined by the *AuthenticationHandler*. This attribute is used by the +HTTP Service implementation to implement the +*HttpServletRequest.getAuthType* method.

*org.apache.sling.commons.auth.ResourceResolver*

The +*ResourceResolver* created from the credentials and the logged in JCR +Session. This attribute may be used by servlets to access the repository. +Namely the *SlingMainServlet* uses this request attribute to provide the +*ResourceResolver* to handle the request.

*javax.jcr.Session*

The JCR Session. This attribute is for backwards +compatibility only. *Its use is deprecated and the attribute will be +removed in future versions*.

*org.apache.sling.commons.auth.spi.AuthenticationInfo*

The +*AuthenticationInfo* object produced from the *AuthenticationHandler*. +

Exit State	Description
Normal	An AuthenticationHandler could be selected to which the +login request could be forwarded.
NoAuthenticationHandlerException	No AuthenticationHandler could +be selected to forward the login request to. In this case, the caller can +proceed as appropriate. For example a servlet, which should just login a +user may send back a 403/FORBIDDEN status because login is not possible. Or +a 404/NOT FOUND handler, which tried to login as a fallback, may continue +and send back the regular 404/NOT FOUND response.
IllegalStateException	The response has already been committed and +the login request cannot be processed. Normally to request login, the +current response must be reset and a new response has to be prepared. This +is only possible if the request has not yet been committed.

Exit State

Description

Normal

An *AuthenticationHandler* could be selected to which the +login request could be forwarded.

*NoAuthenticationHandlerException*

No *AuthenticationHandler* could +be selected to forward the login request to. In this case, the caller can +proceed as appropriate. For example a servlet, which should just login a +user may send back a 403/FORBIDDEN status because login is not possible. Or +a 404/NOT FOUND handler, which tried to login as a fallback, may continue +and send back the regular 404/NOT FOUND response.

*IllegalStateException*

The response has already been committed and +the login request cannot be processed. Normally to request login, the +current response must be reset and a new response has to be prepared. This +is only possible if the request has not yet been committed.

Parameter	Name	Default	Description
Request Log Name	request.log.output	Name of the destination for the request log. The request log logs the entry and exit of each request into and out of the system together with the entry time, exit time, time to process the request, a request counter as well as the final status code and response content type. In terms of Request Logger Service formats, request entry is logged with the format {{%t \[%R](%r.html) + \-> %m %U%q %H}} and request exit is logged with the format {{%\{end}t +\[%R] <\- %s %\{Content-Type}o %Dms}} (See [#Log Format Specification] + below for the specification of the format).
Request Log Type	request.log.outputtype	Type of Logger named with +the Logger Name parameter. See [#Log Output](#log-output.html) + below
Enable Request Log	request.log.enabled	Whether to enable Request +logging or not.
Access Log Name	access.log.output	Name of the destination for the +access log. The access log writes an entry for each request as the request +terminates using the NCSA extended/combined log format. In terms of Request +Logger Service formats the access log is written with the format {{%h %l %u +%t "%r" %>s %b "%\{Referer}i" "%\{User-Agent}i"}} (See [#Log Format Specification](#log-format-specification.html) + below for the specification of the format).
Access Log Type	access.log.outputtype	Type of Logger named with +the Logger Name parameter. See [#Log Output](#log-output.html) + below
Enable Access Log	access.log.enabled	Whether to enable Access +logging or not.

Parameter

Name

Default

Description

Request Log Name

*request.log.output*

Name of the destination for the request log. The request log logs the entry and exit of each request into and out of the system together with the entry time, exit time, time to process the request, a request counter as well as the final status code and response content type. In terms of Request Logger Service formats, request entry is logged with the format {{%t \[%R](%r.html) + \-> %m %U%q %H}} and request exit is logged with the format {{%\{end}t +\[%R] <\- %s %\{Content-Type}o %Dms}} (See [#Log Format Specification] + below for the specification of the format).

Request Log Type

*request.log.outputtype*

Type of Logger named with +the Logger Name parameter. See [#Log Output](#log-output.html) + below

Enable Request Log

*request.log.enabled*

Whether to enable Request +logging or not.

Access Log Name

*access.log.output*

Name of the destination for the +access log. The access log writes an entry for each request as the request +terminates using the NCSA extended/combined log format. In terms of Request +Logger Service formats the access log is written with the format {{%h %l %u +%t "%r" %>s %b "%\{Referer}i" "%\{User-Agent}i"}} (See [#Log Format Specification](#log-format-specification.html) + below for the specification of the format).

Access Log Type

*access.log.outputtype*

Type of Logger named with +the Logger Name parameter. See [#Log Output](#log-output.html) + below

Enable Access Log

*access.log.enabled*

Whether to enable Access +logging or not.

Type Code	Type Name	Description and Logger Name interpretation
0	Logger Name	Writes the logging information to a named SLF4J Logger. +The name of the Logger is defined in the Logger Name property. The actual +destination of the log messages is defined the SLF4J configuration for the +named logger
1	File Name	Writes the logging information to a file, on message per +line. The file name is an absolute or relative path name. If the name is +relative, it is resolved against the sling.home framework property.
2	RequestLog Service	Sends the logging information to a +org.apache.sling.engine.RequestLog service whose requestlog.name +service registration property must the same as the value of the Logger Name +property. If more than one such service is registered, all services are +called. If no such service is registered, the logging information is +discarded. Using RequestLog Services is deprecated.

Type Code

Type Name

Description and Logger Name interpretation

Logger Name

Writes the logging information to a named SLF4J Logger. +The name of the Logger is defined in the Logger Name property. The actual +destination of the log messages is defined the SLF4J configuration for the +named logger

File Name

Writes the logging information to a file, on message per +line. The file name is an absolute or relative path name. If the name is +relative, it is resolved against the *sling.home* framework property.

RequestLog Service

Sends the logging information to a +*org.apache.sling.engine.RequestLog* service whose *requestlog.name* +service registration property must the same as the value of the Logger Name +property. If more than one such service is registered, all services are +called. If no such service is registered, the logging information is +discarded. Using RequestLog Services is deprecated.

Parameter	Name	Default	Description
Log Format	request.log.service.format	Specify a [#Log Format Specification](#log-format-specification.html) + as described below
Logger Type	request.log.service.outputtype	Logger Name/0	+Type of Logger named with the Logger Name parameter. See [#Log Output](#log-output.html) + above
Logger Name	request.log.service.output	request.log	Name of +the Logger to be used. See [#Log Output](#log-output.html) + above
Request Entry	request.log.service.onentry	unchecked/false	+Whether logger is called at the start of request processing or after +processing the request

Parameter

Name

Default

Description

Log Format

*request.log.service.format*

Specify a [#Log Format Specification](#log-format-specification.html) + as described below

Logger Type

*request.log.service.outputtype*

Logger Name/*0*

+Type of Logger named with the Logger Name parameter. See [#Log Output](#log-output.html) + above

Logger Name

*request.log.service.output*

*request.log*

Name of +the Logger to be used. See [#Log Output](#log-output.html) + above

Request Entry

*request.log.service.onentry*

unchecked/*false*

+Whether logger is called at the start of request processing or after +processing the request

Format String	Description
%%	The percent sign
%a	Remote IP-address
%A	Local IP-address
%B	Size of response in bytes, excluding HTTP headers.
%b	Size of response in bytes, excluding HTTP headers. In CLF +format, i.e. a '-' rather than a 0 when no bytes are sent.
%\{Foobar}C	The contents of cookie Foobar in the request sent to +the server.
%D	The time taken to serve the request, in microseconds.
%\{FOOBAR}e	Not supported in Sling; prints nothing.
%f	The absolute path of the resolved resource
%h	Remote host
%H	The request protocol
%\{Foobar}i	The contents of Foobar: header line(s) in the request +sent to the server.
%k	Not supported in Sling; prints nothing.
%l	Not supported in Sling; prints nothing.
%m	The request method
%\{Foobar}n	Not supported in Sling; prints nothing.
%\{Foobar}o	The contents of Foobar: header line(s) in the reply.
%p	The canonical port of the server serving the request
%\{format}p	The canonical port of the server serving the request +or the server's actual port or the client's actual port. Valid formats are +canonical, local, or remote.
%P	The _name of the thread_ -process ID of the child- that +serviced the request.
%\{format}P	Same as %P; the format parameter is ignored.
%q	The query string (prepended with a ? if a query string exists, +otherwise an empty string)
%r	First line of request
%R	The number of requests processed by Sling since the last start. +
%s	Status.
%t	Time the request was received (standard english format)
%\{format}t	Same as %t; the format parameter is ignored +unless it is the literal value _end_ indicating to use the time of request +terminating (instead of the time of request receipt).
%T	The time taken to serve the request, in seconds.
%u	Remote user (from auth; may be bogus if return status (%s) is +401)
%U	The URL path requested, not including any query string.
%v	The canonical ServerName of the server serving the request.
%V	Same as %v.
%X	Not supported in Sling; prints nothing.
%I	Not supported in Sling; prints nothing.
%O	Not supported in Sling; prints nothing.

Format String

Description

*%%*

The percent sign

*%a*

Remote IP-address

*%A*

Local IP-address

*%B*

Size of response in bytes, excluding HTTP headers.

*%b*

Size of response in bytes, excluding HTTP headers. In CLF +format, i.e. a '-' rather than a 0 when no bytes are sent.

*%\{Foobar}C*

The contents of cookie Foobar in the request sent to +the server.

*%D*

The time taken to serve the request, in microseconds.

*%\{FOOBAR}e*

Not supported in Sling; prints nothing.

*%f*

The absolute path of the resolved resource

*%h*

Remote host

*%H*

The request protocol

*%\{Foobar}i*

The contents of Foobar: header line(s) in the request +sent to the server.

*%k*

Not supported in Sling; prints nothing.

*%l*

Not supported in Sling; prints nothing.

*%m*

The request method

*%\{Foobar}n*

Not supported in Sling; prints nothing.

*%\{Foobar}o*

The contents of Foobar: header line(s) in the reply.

*%p*

The canonical port of the server serving the request

*%\{format}p*

The canonical port of the server serving the request +or the server's actual port or the client's actual port. Valid formats are +canonical, local, or remote.

*%P*

The _name of the thread_ -process ID of the child- that +serviced the request.

*%\{format}P*

Same as *%P*; the *format* parameter is ignored.

*%q*

The query string (prepended with a ? if a query string exists, +otherwise an empty string)

*%r*

First line of request

*%R*

The number of requests processed by Sling since the last start. +

*%s*

Status.

*%t*

Time the request was received (standard english format)

*%\{format}t*

Same as *%t*; the *format* parameter is ignored +unless it is the literal value _end_ indicating to use the time of request +terminating (instead of the time of request receipt).

*%T*

The time taken to serve the request, in seconds.

*%u*

Remote user (from auth; may be bogus if return status (%s) is +401)

*%U*

The URL path requested, not including any query string.

*%v*

The canonical ServerName of the server serving the request.

*%V*

Same as *%v*.

*%X*

Not supported in Sling; prints nothing.

*%I*

Not supported in Sling; prints nothing.

*%O*

Not supported in Sling; prints nothing.

Argument	Sling property	Description
-l loglevel	org.apache.sling.osgi.log.level	The initial +loglevel (0..4, FATAL, ERROR, WARN, INFO, DEBUG)
-f logfile	org.apache.sling.osgi.log.file	The log file, "-" +for stdout
-c slinghome	sling.home	the sling context directory
-a address	--	the interfact to bind to (use 0.0.0.0 for any) (not +supported yet)
-p port	org.osgi.service.http.port	the port to listen to +(default 8080)
-h	--	Prints a simple usage message and exits.

Argument

Sling property

Description

*-l loglevel*

*org.apache.sling.osgi.log.level*

The initial +loglevel (0..4, FATAL, ERROR, WARN, INFO, DEBUG)

*-f logfile*

*org.apache.sling.osgi.log.file*

The log file, "-" +for stdout

*-c slinghome*

*sling.home*

the sling context directory

*-a address*

the interfact to bind to (use 0.0.0.0 for any) (not +supported yet)

*-p port*

*org.osgi.service.http.port*

the port to listen to +(default 8080)

*-h*

Prints a simple usage message and exits.

Property	Description
sling.home	Defines the file system location where Project Sling +will write copies of the initial configuration. This property should also +be used to define other local file system locations such as the directory +to use for the Apache Felix Bundle Cache ($\{sling.home}/felix by +default). If this property is not set it defaults to +$\{user.dir}/sling.
sling.home.url	Contains the Sling directory set in the +sling.home property as a valid URL. This property may be used in +situations where the Sling directory is required as an URL. This property +is automatically set by the Sling application and may not be modified by +configuration files.
sling.ignoreSystemProperties	Whether to overwrite any configuration +properties with Java system properties or not. By default this property is +set to true by the Sling Servlet but not set by the Sling main class. +The reason to set this by default in the Sling Servlet is to not induce +values from the environment, which may not be appropriate in the Web +Application case.
obr.repository.url	A comma-separated list of OSGi Bundle Repository +URLs. See _Important Properties_ on the page [Initial Provisioning and Startup](launch-sling.html) +.
sling.install.bundles	A comma-separated list of start level +numbers. See _Important Properties_ on the page [Initial Provisioning and Startup](launch-sling.html) +.
sling.install.	A comma-separated list of bundle specifications. +See _Important Properties_ on the page [Initial Provisioning and Startup](launch-sling.html) +.
org.apache.sling.osgi.log.*	Properties providing initial +configuration to the Sling Log Service. See 'Important Properties' on the +page [Initial Provisioning and Startup](launch-sling.html) +.

Property

Description

*sling.home*

Defines the file system location where Project Sling +will write copies of the initial configuration. This property should also +be used to define other local file system locations such as the directory +to use for the Apache Felix Bundle Cache (*$\{sling.home}/felix* by +default). If this property is not set it defaults to +*$\{user.dir}/sling*.

*sling.home.url*

Contains the Sling directory set in the +*sling.home* property as a valid URL. This property may be used in +situations where the Sling directory is required as an URL. This property +is automatically set by the Sling application and may not be modified by +configuration files.

*sling.ignoreSystemProperties*

Whether to overwrite any configuration +properties with Java system properties or not. By default this property is +set to *true* by the Sling Servlet but not set by the Sling main class. +The reason to set this by default in the Sling Servlet is to not induce +values from the environment, which may not be appropriate in the Web +Application case.

*obr.repository.url*

A comma-separated list of OSGi Bundle Repository +URLs. See _Important Properties_ on the page [Initial Provisioning and Startup](launch-sling.html) +.

*sling.install.bundles*

A comma-separated list of start level +numbers. See _Important Properties_ on the page [Initial Provisioning and Startup](launch-sling.html) +.

*sling.install.*

A comma-separated list of bundle specifications. +See _Important Properties_ on the page [Initial Provisioning and Startup](launch-sling.html) +.

*org.apache.sling.osgi.log.**

Properties providing initial +configuration to the Sling Log Service. See 'Important Properties' on the +page [Initial Provisioning and Startup](launch-sling.html) +.

Group ID	Artifact ID	Version	Scope
org.apache.felix	org.osgi.core	1.2.0	provided
org.apache.felix	org.osgi.compendium	1.2.0	provided
javax.servlet	servlet-api	2.4	provided
javax.jcr	jcr	1.0	provided
org.slf4j	slf4j-api	1.5.2	provided
junit	junit	4.3	test
org.jmock	jmock-junit4	2.2.0	test
org.slf4j	slf4j-simple	1.5.2	test

Group ID

Artifact ID

Version

Scope

org.apache.felix

org.osgi.core

1.2.0

provided

org.apache.felix

org.osgi.compendium

1.2.0

provided

javax.servlet

servlet-api

2.4

provided

javax.jcr

jcr

1.0

provided

org.slf4j

slf4j-api

1.5.2

provided

junit

4.3

test

org.jmock

jmock-junit4

2.2.0

test

org.slf4j

slf4j-simple

1.5.2

test

html.esp

+ + +

<%= currentNode.title %>

+ + + + +To select the script, Sling: +* looks under _/apps_ +* and appends the _sling:resourceType_ value of our node ( which is +_foo/bar_ ) +* and appends _html.esp_, as the extension of our URL is _html_ and the +language of our script is _esp_. + +Store this script under _/apps/foo/bar/html.esp_, either using a WebDAV +client (connected to [http://admin:admin@localhost:8080/](http://admin:admin@localhost:8080/) +), or using cURL as shown here, after creating the _html.esp_ script in the +current directory on your system: + + + curl -X MKCOL -u admin:admin http://localhost:8080/apps/foo + curl -X MKCOL -u admin:admin http://localhost:8080/apps/foo/bar + + +create a local file _html.esp_ and copy above content. + + + curl -u admin:admin -T html.esp http://localhost:8080/apps/foo/bar/html.esp + + +The HTML rendering of your node, at [http://localhost:8080/content/mynode.html](http://localhost:8080/content/mynode.html) +, is now created by this ESP script. You should see the node's title alone +as an

element in that page. + +A script named _POST.esp_ instead of _html.esp_ would be called for a POST +request, _DELETE.esp_ for DELETE, _xml.esp_ for a GET request with a _.xml_ +extension, etc. See [URL to Script Resolution](http://cwiki.apache.org/SLING/url-to-script-resolution.html) + on the Sling wiki for more info. + +Servlets can also be easily "wired" to handle specific resource types, +extensions, etc., in the simplest case by using SCR annotations in the +servlet source code. Servlets and scripts are interchangeable when it comes +to processing Sling requests. + + + +## What next? + +These simple examples show how Sling uses scripts to work with JCR data, +based on _sling:resourceType_ or node types. + +There's much more to Sling of course - you'll find some additional simple +examples below, and above in the _see also_ section. + +We are working on debugging features to help trace the way Sling processes +requests. Have a look at [SLING-3](https://issues.apache.org/jira/browse/SLING-3) + to see what's possible already. + + + +# Additional examples + + +## Let Sling generate the path of a newly created node. + +To create a node with a unique path at a given location, end the URL of the +POST request with _/_. + +In this case, the Sling response redirects to the URL of the created node. + +Start by creating a new _/blog_ folder: + + + curl -X POST -u admin:admin "http://localhost:8080/content/blog" + + +And create a node with a Sling-generated name under it: + + + curl -D - -u admin:admin -F"title=Adventures with Sling" +"http://localhost:8080/content/blog/" + + +Using cURL's _\-D_ option shows the full HTTP response, which includes a +_Location_ header to indicate where the new node was created: + + + Location: /blog/adventures_with_slin + + +The actual node name might not be _adventures_with_slin_ \- depending on +existing content in your repository, Sling will find a unique name for this +new node, based on several well-know property values like title, +description, etc. which are used for this if provided. + +So, in our case, our new node can be displayed in HTML via the [http://localhost:8080/blog/adventures_with_slin.html](http://localhost:8080/blog/adventures_with_slin.html) + URL. + +Note that we didn't set a _sling:resourceType_ property on our node, so if +you want to render that node with a script, you'll have to store the script +under _/apps/nt/unstructured/html.esp_. + + + +## Add a page header with sling.include + +The _sling.include_ function can be called from scripts to include the +rendered result of another node. + +In this example, we create a node at _/content/header_, rendered with a +logo using an _html.esp_ script, then use that header at the top of the +_html.esp_ script that we created previously for the _foo/bar_ resource +type. + +Start by checking that [http://localhost:8080/content/mynode.html](http://localhost:8080/content/mynode.html) + is rendered using the _html.esp_ script created above. + +Create this script and name it _header.esp_: + +
header.esp
+
+
+ + <%= currentNode.headline %> +
+
+ + +Upload it so that it is used to render resources having +_sling:resourceType=foo/header_: + + + curl -X MKCOL -u admin:admin http://localhost:8080/apps/foo/header/ + curl -u admin:admin -T header.esp +http://localhost:8080/apps/foo/header/html.esp + + +Create the header node: + + + curl -u admin:admin -F"sling:resourceType=foo/header" -F"headline=Hello, +Sling world" http://localhost:8080/content/header + + +Upload the logo that the script uses (using sling.jpg or another logo in +the current directory): + + + curl -X MKCOL -u admin:admin http://localhost:8080/images/ + curl -u admin:admin -T sling.jpg http://localhost:8080/images/sling.jpg + + +And check that the header is rendered with the logo at [http://localhost:8080/content/header.html](http://localhost:8080/content/header.html) +. + +Now, update the html.esp script that we created for our first example +above, to include the header: + +
html.esp
+ + +
+ <% sling.include("/content/header"); %> +
+
<%= currentNode.title %>
+ + + + +And upload it again to replace the previous version: + + + curl -u admin:admin -T html.esp http://localhost:8080/apps/foo/bar/html.esp + + +The [http://localhost:8080/content/mynode.html](http://localhost:8080/content/mynode.html) +, once refreshed, now shows the blue headline and logo, and this layout +also applies to any node created with _sling:resourceType=foo/bar_.

URL part	Scheme	Host/Port	Path
Absolute URL	must match	must match	request URL path is prefixed +with the path
Host/Port with Path	ignored	must match	request URL path is prefixed +with the path
Path	ignored	ignored	request URL path is prefixed with the path

Credentials	Login	Consequence
present	successfull	Continue with an authenticated request
present	failed	Select AuthenticationHandler and call +requestCredentials method
missing	anonymous allowed	Continue with a non authenticated request +using anonymous access to the repository
missing	anonymous forbidden	Select AuthenticationHandler and call +requestCredentials method

sling.bootdelegation.simple = com.some.package	This setting +unconditionally adds the com.some.package package to the +org.osgi.framework.bootdelegation property
sling.bootdelegation.class.com.some.other.Main = com.some.other	+This setting checks whether the com.some.other.Main class is known. If +so, the com.some.other package is added to the +org.osgi.framework.bootdelegation property. Otherwise the +com.some.other package is not added - and therefore must be exported by +a bundle if required for use inside the framework.

sling.system.packages.simple = com.some.package	This setting +unconditionally adds the com.some.package package to the +org.osgi.framework.system.packages property
sling.system.packages.class.com.some.other.Main = com.some.other	+This setting checks whether the com.some.other.Main class is known. If +so, the com.some.other package is added to the +org.osgi.framework.system.packages property. Otherwise the +com.some.other package is not added - and therefore must be exported by +a bundle if required for use inside the framework.