Path (inversion-api 0.9.27 API)

java.lang.Object
- io.inversion.utils.Path

```
public class Path
extends java.lang.Object
```
A case insensitive utility abstraction for working with forward slash based paths /like/you/find/in/urls.
When working with Paths, leading and trailing slashes are completely disregarded. Any leading and trailing slashes in the documentation are illustrative only and could be excluded to achieve the same result. Multiple consecutive slashes are treated as a single slash. There will never be an empty string or null path part.
In addition to representing concrete paths, such as a file path or url path, a Path object may contain wildcards, regular expressions, and variable name bindings which are used when comparing a variablized abstract paths with a concrete path.
Paths are primarily used to configure Rules (Engine, Api, Endpoint and Action are all subclasses of Rule) to match against inbound Request urls to determine how the Request will be processed.
Paths can be variablized as follows:
- /animals/* - will match anything that starts with "animals/". "*" matches any number of path segments including zero segments (meaning "animals/" alone will match and so will "animals/dogs/fido"). "*" wildcards are only valid as the last segment in a path.
- /animals/dogs/:dogName - if a path segment starts with a ":" it indicates that the value can be anything but a value is required and should be mapped to the corresponding variable name, in this case "dogName", by whoever is doing the path matching.
- /animals/dogs/{fido|ralph|jackie} - if the path segment is wrapped in "{}" the contents are considered a regular expression Pattern for matching
- /animals/dogs/${fido|ralph|jackie} - a '$' can prefix '{}' as syntatic sugar some may be familiar with.
- /animals/dogs/{dogName:fido|ralph|jackie} - again a regex, this time with a variable binding to "dogName"
- /animals/[{dogs|cats|snakes}]/:animalName/* - if something is wrapped in square brackets "[]" that segment and all subsequent segments are optional. If the segments exists in the path being compared to, they must match the supplied rules, but if the comparison path ends right before the first optional segment, the paths still match.
When used in the context of a Api configuration you may see something like this:
```
  Engine e = new Engine().withIncludeOn(null, new Path("/apis"));
                         .withApi(new Api().withIncludeOn(null, new Path("bookstore/{storeName:johnsBestBooks|carolsBooksOnMain}"))
                                           .withEndpoint(new Endpoint().withIncludeOn(null, new Path("categories/:category/"))
                                                                       .withAction(new BrowseCategoriesAction().withIncludeOn(null, new Path("[:subcategory]/*")))));
 
```
See Also:

Rule.withIncludeOn(io.inversion.Rule.RuleMatcher), Rule.withExcludeOn(java.lang.String, java.lang.String)

Constructor Summary

Constructors
Constructor and Description
`Path()` Creates an empty Path
`Path(java.util.List<java.lang.String> parts)` Convenience overload of `Path(String...)`.
`Path(Path path)` Creates a clone of the supplied `Path`
`Path(java.lang.String... part)` Constructs a Path based on all of the supplied `part`s.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(java.lang.String parts)` Adds `part` to the end of the Path.
`boolean`	`equals(java.lang.Object o)`
`Path`	`extract(java.util.Map params, Path toMatch)` Convenience overloading of `extract(Map, Path, boolean)` with `greedy = true`.
`Path`	`extract(java.util.Map params, Path matchingConcretePath, boolean greedy)` Consumes the matching parts of `matchingConcretePath` and extracts any named variable to `matchingConcretePath` if this any of this paths parts contain variable bindings.
`java.lang.String`	`first()` Simple way to pull the first element of the path without having to check for `size() > 0` first.
`java.lang.String`	`get(int index)` Simple way to get element at `index` without haveint to check for `size() > index` first.
`java.lang.String`	`getVarName(int index)` Extracts a variable name form the path expression if `index` exists and has a var name.
`boolean`	`isOptional(int index)` Square brackets, '[]', indicate that a path path (and by implication, all following parts) are considered optional for path matching.
`boolean`	`isStatic(int index)` Checks to see if the value at `index` is a wildcard, a variable, or is optional.
`boolean`	`isVar(int index)` Check to see if the value at `index` starts with '${', '{', ':' after removing any leading '[' characters.
`boolean`	`isWildcard(int index)` Check if the path part at `index` is equal to '*' without having to check if `size() @lt; index` first.
`java.lang.String`	`last()` Simple way to pull the last element of the path without having to check for `size() > 0` first.
`boolean`	`matches(Path concretePath)` Checks if this Path is as case insensitive match, including any optional rules, wildcards, and regexes to `concretePath`.
`boolean`	`matches(java.lang.String toMatch)` Convenience overloading of `matches(Path)`.
`java.util.List<java.lang.String>`	`parts()` Gets the path parts as a List.
`java.lang.String`	`remove(int index)` Simple way to remove the path part at `index` without having to check for `size() @lt; index` first.
`int`	`size()`
`boolean`	`startsWith(java.util.List<java.lang.String> partsToMatch)` Performs a case insensitive string match between this Path and `pathsToMatch`.
`Path`	`subpath(int fromIndex, int toIndex)` Creates a new sub Path.
`java.lang.String`	`toString()`

Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Path
```
public Path()
```
    Creates an empty Path
  - Path
```
public Path(Path path)
```
    Creates a clone of the supplied Path
    
    Parameters:
    
    path - the Path to be cloned
  - Path
```
public Path(java.lang.String... part)
```
    Constructs a Path based on all of the supplied parts.
    The strings in part may themselves contain "/" characters and will be split into multiple parts correspondingly. Meaning Path p = new Path("part1", "part2/part3", "/part4/", "////part5//part6/", "part7") is valid and would result in a Path with parts "part1", "part2", "part3", "part4", "part5", "part6", "part7".
    
    Parameters:
    
    part - an array of path part strings
  - Path
```
public Path(java.util.List<java.lang.String> parts)
```
    Convenience overload of Path(String...).
    
    Parameters:
    
    parts - an list of path part strings
- Method Detail
  - parts
```
public java.util.List<java.lang.String> parts()
```
    Gets the path parts as a List.
    Method signature could easily have been "asList()"
    
    Returns:
    
    a new list with the individual path parts n the originally defined case.
  - first
```
public java.lang.String first()
```
    Simple way to pull the first element of the path without having to check for size() > 0 first.
    
    Returns:
    
    the first element in the path if it exists otherwise null
  - last
```
public java.lang.String last()
```
    Simple way to pull the last element of the path without having to check for size() > 0 first.
    
    Returns:
    
    the last element in the path if it exists otherwise null
  - get
```
public java.lang.String get(int index)
```
    Simple way to get element at index without haveint to check for size() > index first.
    
    Parameters:
    
    index - the index of the path part to retrive
    
    Returns:
    
    the path part at index if it exists otherwise null
  - add
```
public void add(java.lang.String parts)
```
    Adds part to the end of the Path.
    The parts is exploded via Utils.explode('/', part) first so while the part arg is a single value, it could result in multiple additions.
    
    Parameters:
    
    parts - path parts to add
  - remove
```
public java.lang.String remove(int index)
```
    Simple way to remove the path part at index without having to check for size() @lt; index first.
    
    Parameters:
    
    index - the index of the path part to remove
    
    Returns:
    
    the path part previously located at index if it existed otherwise null
  - startsWith
```
public boolean startsWith(java.util.List<java.lang.String> partsToMatch)
```
    Performs a case insensitive string match between this Path and pathsToMatch.
    Wildcards and regular expressions are not supported in this method, only straight case insensitive string comparison.
    
    Parameters:
    
    partsToMatch - the path parts to to match against
    
    Returns:
    
    true if each index of partsToMatch is a case insensitive match to this Path at the same index otherwise false.
  - size
```
public int size()
```
    Returns:
    
    the number of parts in the Path
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a pretty printed "/" separated path string representation
  - equals
```
public boolean equals(java.lang.Object o)
```
    Overrides:
    
    equals in class java.lang.Object
    
    Returns:
    
    true of the objects string representations match
  - subpath
```
public Path subpath(int fromIndex,
                    int toIndex)
```
    Creates a new sub Path.
    
    Parameters:
    
    fromIndex - low endpoint (inclusive) of the subList
    
    toIndex - high endpoint (exclusive) of the subList
    
    Returns:
    
    a subpath from fromIndex (inclusive) to toIndex (exclusive)
  - isStatic
```
public boolean isStatic(int index)
```
    Checks to see if the value at index is a wildcard, a variable, or is optional.
    
    Parameters:
    
    index - the path part to check
    
    Returns:
    
    true if the path part at index is a '*' char or starts with '[', '{' or ':'
  - isWildcard
```
public boolean isWildcard(int index)
```
    Check if the path part at index is equal to '*' without having to check if size() @lt; index first.
    
    Parameters:
    
    index - the path part to check
    
    Returns:
    
    true if the path part at index
  - isVar
```
public boolean isVar(int index)
```
    Check to see if the value at index starts with '${', '{', ':' after removing any leading '[' characters.
    
    Parameters:
    
    index - the index to check
    
    Returns:
    
    true if the value exists and is variableized but not a wildcard, false otherwise.
  - getVarName
```
public java.lang.String getVarName(int index)
```
    Extracts a variable name form the path expression if index exists and has a var name.
    'varName' would be extracted from getVarName(1) for the following paths.
    - /part/:varName/
    - /part/{varNam:regex}/
    - /part/${varNam:regex}/
    Square brackets indicating a path component is optioanl don't impact retrieval of the var name so the following would return the same as there above counterparts:
    - /part/[:varName]/
    - /[part]/{varNam:regex}]/
    - /[part]/[${varNam:regex}]/
    Parameters:
    
    index - the index of the var name to get
    
    Returns:
    
    the variable name binding for the parth part at index if it exists
  - isOptional
```
public boolean isOptional(int index)
```
    Square brackets, '[]', indicate that a path path (and by implication, all following parts) are considered optional for path matching.
    For example: new Path("first/second/[third]/").matches(new Path("first/second/third"))
    
    Parameters:
    
    index - the part part to check
    
    Returns:
    
    true if the path part at index exists and starts with '[' and ends with ']'
  - matches
```
public boolean matches(java.lang.String toMatch)
```
    Convenience overloading of matches(Path).
    
    Parameters:
    
    toMatch - the path string to match
    
    Returns:
    
    true if the paths match
  - matches
```
public boolean matches(Path concretePath)
```
    Checks if this Path is as case insensitive match, including any optional rules, wildcards, and regexes to concretePath.
    As the name implies concretePath is considered to be a literal path not containing optionals, wildcards, and regexes.
    As also documented above:
    - paths can end with a "/*" character meaning this and all following parts are optional and unconstrained
    - wrapping a path part in square brackets, '[]' indicates that it and all following part parts are optional.
    - wrapping a path part in '${}' or '${}' indicates that this path part should match via a regular expression such as '${[0-9a-fA-F]{1,8}}' to match a 1 to 8 character alpha numeric part
    - you can bind a variable name to a regex by preceding the regex with a name and a colon '/${id:[0-9a-fA-F]{1,8}}/'
    - starting a path part with a ':' such as '/:id/' is functionally equivalent to '/${id:.*}'
    All non regex comparisons are performed with String.equalsIgnoreCase.
    All regexes are compiled with Pattern.CASE_INSENSITIVE.
    Parameters:
    
    concretePath - the path to match against
    
    Returns:
    
    true if this path matches concretePath
  - extract
```
public Path extract(java.util.Map params,
                    Path toMatch)
```
    Convenience overloading of extract(Map, Path, boolean) with greedy = true.
    
    Parameters:
    
    params - a map to add extracted name/value pairs to
    
    toMatch - the path to extract from
    
    Returns:
    
    the part of this path that matched
    
    See Also:
    
    extract(Map, Path, boolean)
  - extract
```
public Path extract(java.util.Map params,
                    Path matchingConcretePath,
                    boolean greedy)
```
    Consumes the matching parts of matchingConcretePath and extracts any named variable to matchingConcretePath if this any of this paths parts contain variable bindings.
    If greedy is true, the match will consume through matching optional path parts.
    If greedy is false, variable bindings in any optional paths parts will be extracted but the parts will not be removed from matchingConcretePath.
    Here is an example:
```
   Map params = new HashMap();
   Path engineMatch = new Path("apis/myapi/*");
   Path apiMatch = new Path("${version:v1|v2}/:tenant")
   Path endpointMatch = new Path("[${collection:books|categories|orders}]/*");
   Path actionMatch = new Path("[:orderId]/*");

   Path requestPath = new Path("/apis/myapi/v2/bobsBooks/orders/67890");

   engineMatch.extract(requestPath);
   // params is empty, requestPath is now 'v2/bobsBooks/orders/67890'

   apiMatch.extract(requestPath);
   //version=v2 and tenant=bobsBooks have been added to params and requestPath is now 'orders/67890'

   endpointMatch.extract(requestPath);
   //collection=orders has been added to params and requestPath is now '67890'

   actionMatch.extract(requestPath);
   //orderId=67890 has been added to params and requestPath is now empty.
 
```
    The above example is very similar to how an Engine processes paths when selecting an Api, Endpoint, and Actions to run.
    Engine will also add the params to the Request Url params as if they had been supplied as name value pairs by the caller on the query string.
    Parameters:
    
    params - the map to add extracted name/value pairs to
    
    matchingConcretePath - the path to extract from
    
    greedy - if extraction should consume through optional path parts
    
    Returns:
    
    the same Path object that was passed in but potentially now shorter as matching segments may have been consumed
    
    See Also:
    
    Engine.service(Request, Response), Chain.next()

Class Path

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Path

Path

Path

Path

Method Detail

parts

first

last

get

add

remove

startsWith

size

toString

equals

subpath

isStatic

isWildcard

isVar

getVarName

isOptional

matches

matches

extract

extract