2.15.1.2.2.  Path parameters - Regular expression support

Path parameters allow associating a portion of the request path with a parameter. Such parameter will match any non empty portions of text except the / character (that is the [^/]+ regular expression). Otherwise, they can be associated with a regular expression for matching specific patterns. Path parameters are mandatory for matching since they are a part of the request path, however it is allowed to write regular expression matching an empty value.

Encoding

Path parameters may contain the '/' character which is a reserved char for the URI path. This case is specially handled by the navigation controller by using a special character to replace the '/' literals. By default, the character is the colon ":" and can be changed to other possible values (see controller XML schema for possible values) to give a greater amount of flexibility.

This encoding is applied only when the encoding is performed for parameters having a mode set to the default-form value, for instance, it does not happen for navigation node URI (for which / is encoded literally). The separator escape char can still be used but under it is percent escaped form, so by default, a path parameter value containing the colon ":" would be encoded as %3A and conversely the %3A value will be decoded as the colon ":".

For example, when no pattern is defined, the default one [^/]+ will be used:


<route path="/{gtn:path}">
</route>

As a result of the example above, routing and rendering are as below:

Routing and Rendering
Path "/foo"      <--> the map (gtn:path=foo)

Path "/foo:bar"  <--> the map (gtn:path=foo/bar)

If the request path contains another "/" char, it will not work. The default encoding mode is default-form. In the example above, "/foo/bar" is not matched, so the system returns an empty parameter map.

However, this problem could be solved with the following configuration:


<route path="/{gtn:path}">
  <path-param encoding="preserve-path" qname="gtn:path">
    <pattern>.*</pattern>
  </path-param>
</route>
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