NodeListModel (FreeMarker 2.3.23 API)
Date: 2015-07-05

freemarker.ext.jdom

## Class NodeListModel

- java.lang.Object
- - freemarker.ext.jdom.NodeListModel

- All Implemented Interfaces:
    TemplateCollectionModel, TemplateHashModel, TemplateMethodModel, TemplateModel, TemplateScalarModel, TemplateSequenceModel

  Deprecated.
  Use `NodeModel` instead.

      public class NodeListModel
      extends Object
      implements TemplateHashModel, TemplateMethodModel, TemplateCollectionModel, TemplateSequenceModel, TemplateScalarModel

  Provides a template for wrapping JDOM objects. It is capable of storing not only a single JDOM node, but a list of JDOM nodes at once (hence the name). Each node is an instance of any of the core JDOM node classes (except namespaces, which are not supported at the moment), or String for representing text. See individual method documentation for exact details on how the class works. In short:
  - `getAsString()` will render all contained nodes as XML fragment,
  - `exec(List)` provides full XPath functionality implemented on top of the Jaxen library,
  - `get(String)` provides node traversal, copying and filtering - somewhat less expressive than XPath, however it does not require the external library and it evaluates somewhat faster
  - being a `TemplateCollectionModel` allows to iterate the contained node list, and
  - being a `TemplateSequenceModel` allows to access the contained nodes by index and query the node count.

  Note: There is a JDOM independent re-implementation of this class: `freemarker.ext.xml.NodeListModel`

- - ### Field Summary

    - ### Fields inherited from interface freemarker.template.TemplateScalarModel

      `EMPTY_STRING`

    - ### Fields inherited from interface freemarker.template.TemplateModel

      `NOTHING`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `NodeListModel(org.jdom.Document document)` Deprecated. Creates a node list that holds a single `Document` node.
    `NodeListModel(org.jdom.Element element)` Deprecated. Creates a node list that holds a single `Element` node.
    `NodeListModel(List nodes)` Deprecated. Creates a node list that holds a list of nodes.
    `NodeListModel(List nodes, boolean copy)` Deprecated. Creates a node list that holds a list of nodes.

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
    Modifier and Type | Method and Description
    --- | ---
    `Object` | `exec(List arguments)` Deprecated. Applies an XPath expression to the node list and returns the resulting node list.
    `TemplateModel` | `get(int i)` Deprecated. Retrieves the i-th element of the node list.
    `TemplateModel` | `get(String key)` Deprecated. Provides node list traversal as well as special functions: filtering by name, filtering by node type, shallow-copying, and duplicate removal.
    `String` | `getAsString()` Deprecated. This method returns the string resulting from concatenation of string representations of its nodes.
    `boolean` | `isEmpty()` Deprecated. Returns true if this model contains no nodes.
    `TemplateModelIterator` | `iterator()` Deprecated. Retrieves a template model iterator that is used to iterate over the elements in this collection.
    `static void` | `main(String[] args)` Deprecated. Will be removed (main method in a library, often classified as CWE-489 "Leftover Debug Code").
    `void` | `registerNamespace(String prefix, String uri)` Deprecated. Registers an XML namespace with this node list.
    `int` | `size()` Deprecated.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### NodeListModel

          public NodeListModel(org.jdom.Document document)

      Deprecated.
      Creates a node list that holds a single `Document` node.

    - #### NodeListModel

          public NodeListModel(org.jdom.Element element)

      Deprecated.
      Creates a node list that holds a single `Element` node.

    - #### NodeListModel

          public NodeListModel(List nodes)

      Deprecated.
      Creates a node list that holds a list of nodes.
      Parameters:
        `nodes` - the list of nodes this template should hold. The created template will copy the passed nodes list, so changes to the passed list will not affect the model.

    - #### NodeListModel

          public NodeListModel(List nodes,
                               boolean copy)

      Deprecated.
      Creates a node list that holds a list of nodes.
      Parameters:
        `nodes` - the list of nodes this template should hold.
        `copy` - if true, the created template will copy the passed nodes list, so changes to the passed list will not affect the model. If false, the model will reference the passed list and will sense changes in it, although no operations on the list will be synchronized.

  - ### Method Detail

    - #### isEmpty

          public boolean isEmpty()

      Deprecated.
      Returns true if this model contains no nodes.
      Specified by:
        `isEmpty` in interface `TemplateHashModel`

    - #### getAsString

          public String getAsString()
                             throws TemplateModelException

      Deprecated.
      This method returns the string resulting from concatenation of string representations of its nodes. Each node is rendered using its XML serialization format, while text (String) is rendered as itself. This greatly simplifies creating XML-transformation templates, as to output a node contained in variable x as XML fragment, you simply write ${x} in the template.
      Specified by:
        `getAsString` in interface `TemplateScalarModel`
      Throws:
        `TemplateModelException`

    - #### get

          public TemplateModel get(String key)
                            throws TemplateModelException

      Deprecated.
      Provides node list traversal as well as special functions: filtering by name, filtering by node type, shallow-copying, and duplicate removal. While not as powerful as the full XPath support built into the `exec(List)` method, it does not require the external Jaxen library to be present at run time. Below are listed the recognized keys. In key descriptions, "applicable to this-and-that node type" means that if a key is applied to a node list that contains a node of non-applicable type a TemplateMethodModel will be thrown. However, you can use `_ftype` key to explicitly filter out undesired node types prior to applying the restricted-applicability key. Also "current nodes" means nodes contained in this set.
      - `*` or `_children`: all direct element children of current nodes (non-recursive). Applicable to element and document nodes.
      - `@*` or `_attributes`: all attributes of current nodes. Applicable to elements only.
      - `_content` the complete content of current nodes (non-recursive). Applicable to elements and documents.
      - `_text`: the text of current nodes, one string per node (non-recursive). Applicable to elements, attributes, comments, processing instructions (returns its data) and CDATA sections. The reserved XML characters ('<' and '&') are escaped.
      - `_plaintext`: same as `_text`, but does not escape any characters, and instead of returning a NodeList returns a SimpleScalar.
      - `_name`: the names of current nodes, one string per node (non-recursive). Applicable to elements and attributes (returns their local name), entities, processing instructions (returns its target), doctypes (returns its public ID)
      - `_qname`: the qualified names of current nodes in `[namespacePrefix:]localName` form, one string per node (non-recursive). Applicable to elements and attributes
      - `_cname`: the canonical names of current nodes (namespace URI + local name), one string per node (non-recursive). Applicable to elements and attributes
      - `_nsprefix`: namespace prefixes of current nodes, one string per node (non-recursive). Applicable to elements and attributes
      - `_nsuri`: namespace URIs of current nodes, one string per node (non-recursive). Applicable to elements and attributes
      - `_parent`: parent elements of current nodes. Applicable to element, attribute, comment, entity, processing instruction.
      - `_ancestor`: all ancestors up to root element (recursive) of current nodes. Applicable to same node types as `_parent`.
      - `_ancestorOrSelf`: all ancestors of current nodes plus current nodes. Applicable to same node types as `_parent`.
      - `_descendant`: all recursive descendant element children of current nodes. Applicable to document and element nodes.
      - `_descendantOrSelf`: all recursive descendant element children of current nodes plus current nodes. Applicable to document and element nodes.
      - `_document`: all documents the current nodes belong to. Applicable to all nodes except text.
      - `_doctype`: doctypes of the current nodes. Applicable to document nodes only.
      - `_fname`: is a filter-by-name template method model. When called, it will yield a node list that contains only those current nodes whose name matches one of names passed as argument. Attribute names should NOT be prefixed with the at sign (@). Applicable on all node types, however has no effect on unnamed nodes.
      - `_ftype`: is a filter-by-type template method model. When called, it will yield a node list that contains only those current nodes whose type matches one of types passed as argument. You should pass a single string to this method containing the characters of all types to keep. Valid characters are: e (Element), a (Attribute), n (Entity), d (Document), t (DocType), c (Comment), p (ProcessingInstruction), x (text). If the string anywhere contains the exclamation mark (!), the filter's effect is inverted.
      - `_type`: Returns a one-character String SimpleScalar containing the typecode of the first node in the node list. Valid characters are: e (Element), a (Attribute), n (Entity), d (Document), t (DocType), c (Comment), p (ProcessingInstruction), x (text). If the type of the node is unknown, returns '?'. If the node list is empty, returns an empty string scalar.
      - `_unique`: a copy of the current nodes that keeps only the first occurrence of every node, eliminating duplicates. Duplicates can occur in the node list by applying uptree-traversals `_parent`, `_ancestor`, `_ancestorOrSelf`, and `_document`. I.e. `foo._children._parent` will return a node list that has duplicates of nodes in foo - each node will have the number of occurrences equal to the number of its children. In these cases, use `foo._children._parent._unique` to eliminate duplicates. Applicable to all node types.
      - `_copy`: a copy of the current node list. It is a shallow copy that shares the underlying node list with this node list, however it has a separate namespace registry, so it can be used to guarantee that subsequent changes to the set of registered namespaces does not affect the node lists that were used to create this node list. Applicable to all node types.
      - `_registerNamespace(prefix, uri)`: register a XML namespace with the specified prefix and URI for the current node list and all node lists that are derived from the current node list. After registering, you can use the `nodelist["prefix:localname"]` or `nodelist["@prefix:localname"]` syntaxes to reach elements and attributes whose names are namespace-scoped. Note that the namespace prefix need not match the actual prefix used by the XML document itself since namespaces are compared solely by their URI. You can also register namespaces from Java code using the `registerNamespace(String, String)` method.
      - `@attributeName`: named attributes of current nodes. Applicable to elements, doctypes and processing instructions. On doctypes it supports attributes `publicId`, `systemId` and `elementName`. On processing instructions, it supports attributes `target` and `data`, as well as any other attribute name specified in data as `name="value"` pair. The attribute nodes for doctype and processing instruction are synthetic, and as such have no parent. Note, however that `@*` does NOT operate on doctypes or processing instructions.
      - any other key: element children of current nodes with name matching the key. This allows for convenience child traversal in `book.chapter.title` style syntax. Note that `nodeset.childname` is technically equivalent to `nodeset._children._fname("childname")`, but is both shorter to write and evaluates faster. Applicable to document and element nodes.
      The order of nodes in the resulting set is the order of evaluation of the key on each node in this set from left to right. Evaluation of the key on a single node always yields the results in "natural" order (that of the document preorder traversal), even for uptree traversals. As a consequence, if this node list's nodes are listed in natural order, applying any of the keys will produce a node list that is also naturally ordered. As a special case, all node lists that are directly or indirectly generated from a single Document or Element node through repeated invocations of this method will be naturally ordered.
      Specified by:
        `get` in interface `TemplateHashModel`
      Parameters:
        `key` - a key that identifies a required set of nodes
      Returns:
        a new NodeListModel that represents the requested set of nodes.
      Throws:
        `TemplateModelException`

    - #### iterator

          public TemplateModelIterator iterator()

      Deprecated.
      Description copied from interface: `TemplateCollectionModel`
      Retrieves a template model iterator that is used to iterate over the elements in this collection.
      Specified by:
        `iterator` in interface `TemplateCollectionModel`

    - #### get

          public TemplateModel get(int i)
                            throws TemplateModelException

      Deprecated.
      Retrieves the i-th element of the node list.
      Specified by:
        `get` in interface `TemplateSequenceModel`
      Returns:
        the item at the specified index, or `null` if the index is out of bounds. Note that a `null` value is interpreted by FreeMarker as "variable does not exist", and accessing a missing variables is usually considered as an error in the FreeMarker Template Language, so the usage of a bad index will not remain hidden, unless the default value for that case was also specified in the template.
      Throws:
        `TemplateModelException`

    - #### size

          public int size()

      Deprecated.
      Specified by:
        `size` in interface `TemplateSequenceModel`
      Returns:
        the number of items in the list.

    - #### exec

          public Object exec(List arguments)
                      throws TemplateModelException

      Deprecated.
      Applies an XPath expression to the node list and returns the resulting node list. In order for this method to work, your application must have access Jaxen library classes. The implementation does cache the parsed format of XPath expressions in a weak hash map, keyed by the string representation of the XPath expression. As the string object passed as the argument is usually kept in the parsed FreeMarker template, this ensures that each XPath expression is parsed only once during the lifetime of the FreeMarker template that contains it.
      Specified by:
        `exec` in interface `TemplateMethodModel`
      Parameters:
        `arguments` - the list of arguments. Must contain exactly one string that is the XPath expression you wish to apply. The XPath expression can use any namespace prefixes that were defined using the `registerNamespace(String, String)` method or the `nodelist._registerNamespace(prefix, uri)` expression in the template.
      Returns:
        a NodeListModel representing the nodes that are the result of application of the XPath to the current node list.
      Throws:
        `TemplateModelException`

    - #### registerNamespace

          public void registerNamespace(String prefix,
                                        String uri)

      Deprecated.
      Registers an XML namespace with this node list. Once registered, you can refer to the registered namespace using its prefix in the `get(String)` method from this node list and all other node lists that are derived from this node list. Use the `nodelist["prefix:localname"]` or the `nodelist["@prefix:localname"]` syntax to reach elements and attributes whose names are namespace-scoped. Note that the namespace prefix need not match the actual prefix used by the XML document itself since namespaces are compared solely by their URI. You can also register namespaces during template evaluation using the `nodelist._registerNamespace(prefix, uri)` syntax in the template. This mechanism is completely independent from the namespace declarations in the XML document itself; its purpose is to give you an easy way to refer to namespace-scoped elements in `get(String)` and in XPath expressions passed to `exec(List)`. Note also that the namespace prefix registry is shared among all node lists that are created from a single node list - modifying the registry in one affects all others as well. If you want to obtain a namespace "detached" copy of the node list, use the `_copy` key on it (or call `nodeList.get("_copy")` directly from your Java code. The returned node list has all the namespaces that the original node list has, but they can be manipulated independently thereon.

    - #### main

          public static void main(String[] args)
                           throws Exception

      Deprecated. Will be removed (main method in a library, often classified as CWE-489 "Leftover Debug Code").
      Loads a template from a file passed as the first argument, loads an XML document from the standard input, passes it to the template as variable `document` and writes the result of template processing to standard output.
      Throws:
        `Exception`