includes/parser/Preprocessor.php

   1 <?php
   2 /**
   3  * Interfaces for preprocessors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Parser
  22  */
  23
  24 /**
  25  * @ingroup Parser
  26  */
  27 interface Preprocessor {
  28         /**
  29          * Create a new preprocessor object based on an initialised Parser object
  30          *
  31          * @param Parser $parser
  32          */
  33         function __construct( $parser );
  34
  35         /**
  36          * Create a new top-level frame for expansion of a page
  37          *
  38          * @return PPFrame
  39          */
  40         function newFrame();
  41
  42         /**
  43          * Create a new custom frame for programmatic use of parameter replacement
  44          * as used in some extensions.
  45          *
  46          * @param array $args
  47          *
  48          * @return PPFrame
  49          */
  50         function newCustomFrame( $args );
  51
  52         /**
  53          * Create a new custom node for programmatic use of parameter replacement
  54          * as used in some extensions.
  55          *
  56          * @param array $values
  57          */
  58         function newPartNodeArray( $values );
  59
  60         /**
  61          * Preprocess text to a PPNode
  62          *
  63          * @param string $text
  64          * @param int $flags
  65          *
  66          * @return PPNode
  67          */
  68         function preprocessToObj( $text, $flags = 0 );
  69 }
  70
  71 /**
  72  * @ingroup Parser
  73  */
  74 interface PPFrame {
  75         const NO_ARGS = 1;
  76         const NO_TEMPLATES = 2;
  77         const STRIP_COMMENTS = 4;
  78         const NO_IGNORE = 8;
  79         const RECOVER_COMMENTS = 16;
  80
  81         const RECOVER_ORIG = 27; // = 1|2|8|16 no constant expression support in PHP yet
  82
  83         /** This constant exists when $indexOffset is supported in newChild() */
  84         const SUPPORTS_INDEX_OFFSET = 1;
  85
  86         /**
  87          * Create a child frame
  88          *
  89          * @param array|bool $args
  90          * @param bool|Title $title
  91          * @param int $indexOffset A number subtracted from the index attributes of the arguments
  92          *
  93          * @return PPFrame
  94          */
  95         function newChild( $args = false, $title = false, $indexOffset = 0 );
  96
  97         /**
  98          * Expand a document tree node, caching the result on its parent with the given key
  99          */
 100         function cachedExpand( $key, $root, $flags = 0 );
 101
 102         /**
 103          * Expand a document tree node
 104          */
 105         function expand( $root, $flags = 0 );
 106
 107         /**
 108          * Implode with flags for expand()
 109          */
 110         function implodeWithFlags( $sep, $flags /*, ... */ );
 111
 112         /**
 113          * Implode with no flags specified
 114          */
 115         function implode( $sep /*, ... */ );
 116
 117         /**
 118          * Makes an object that, when expand()ed, will be the same as one obtained
 119          * with implode()
 120          */
 121         function virtualImplode( $sep /*, ... */ );
 122
 123         /**
 124          * Virtual implode with brackets
 125          */
 126         function virtualBracketedImplode( $start, $sep, $end /*, ... */ );
 127
 128         /**
 129          * Returns true if there are no arguments in this frame
 130          *
 131          * @return bool
 132          */
 133         function isEmpty();
 134
 135         /**
 136          * Returns all arguments of this frame
 137          */
 138         function getArguments();
 139
 140         /**
 141          * Returns all numbered arguments of this frame
 142          */
 143         function getNumberedArguments();
 144
 145         /**
 146          * Returns all named arguments of this frame
 147          */
 148         function getNamedArguments();
 149
 150         /**
 151          * Get an argument to this frame by name
 152          */
 153         function getArgument( $name );
 154
 155         /**
 156          * Returns true if the infinite loop check is OK, false if a loop is detected
 157          *
 158          * @param Title $title
 159          * @return bool
 160          */
 161         function loopCheck( $title );
 162
 163         /**
 164          * Return true if the frame is a template frame
 165          */
 166         function isTemplate();
 167
 168         /**
 169          * Set the "volatile" flag.
 170          *
 171          * Note that this is somewhat of a "hack" in order to make extensions
 172          * with side effects (such as Cite) work with the PHP parser. New
 173          * extensions should be written in a way that they do not need this
 174          * function, because other parsers (such as Parsoid) are not guaranteed
 175          * to respect it, and it may be removed in the future.
 176          *
 177          * @param bool $flag
 178          */
 179         function setVolatile( $flag = true );
 180
 181         /**
 182          * Get the "volatile" flag.
 183          *
 184          * Callers should avoid caching the result of an expansion if it has the
 185          * volatile flag set.
 186          *
 187          * @see self::setVolatile()
 188          * @return bool
 189          */
 190         function isVolatile();
 191
 192         /**
 193          * Get the TTL of the frame's output.
 194          *
 195          * This is the maximum amount of time, in seconds, that this frame's
 196          * output should be cached for. A value of null indicates that no
 197          * maximum has been specified.
 198          *
 199          * Note that this TTL only applies to caching frames as parts of pages.
 200          * It is not relevant to caching the entire rendered output of a page.
 201          *
 202          * @return int|null
 203          */
 204         function getTTL();
 205
 206         /**
 207          * Set the TTL of the output of this frame and all of its ancestors.
 208          * Has no effect if the new TTL is greater than the one already set.
 209          * Note that it is the caller's responsibility to change the cache
 210          * expiry of the page as a whole, if such behavior is desired.
 211          *
 212          * @see self::getTTL()
 213          * @param int $ttl
 214          */
 215         function setTTL( $ttl );
 216
 217         /**
 218          * Get a title of frame
 219          *
 220          * @return Title
 221          */
 222         function getTitle();
 223 }
 224
 225 /**
 226  * There are three types of nodes:
 227  *     * Tree nodes, which have a name and contain other nodes as children
 228  *     * Array nodes, which also contain other nodes but aren't considered part of a tree
 229  *     * Leaf nodes, which contain the actual data
 230  *
 231  * This interface provides access to the tree structure and to the contents of array nodes,
 232  * but it does not provide access to the internal structure of leaf nodes. Access to leaf
 233  * data is provided via two means:
 234  *     * PPFrame::expand(), which provides expanded text
 235  *     * The PPNode::split*() functions, which provide metadata about certain types of tree node
 236  * @ingroup Parser
 237  */
 238 interface PPNode {
 239         /**
 240          * Get an array-type node containing the children of this node.
 241          * Returns false if this is not a tree node.
 242          */
 243         function getChildren();
 244
 245         /**
 246          * Get the first child of a tree node. False if there isn't one.
 247          *
 248          * @return PPNode
 249          */
 250         function getFirstChild();
 251
 252         /**
 253          * Get the next sibling of any node. False if there isn't one
 254          */
 255         function getNextSibling();
 256
 257         /**
 258          * Get all children of this tree node which have a given name.
 259          * Returns an array-type node, or false if this is not a tree node.
 260          */
 261         function getChildrenOfType( $type );
 262
 263         /**
 264          * Returns the length of the array, or false if this is not an array-type node
 265          */
 266         function getLength();
 267
 268         /**
 269          * Returns an item of an array-type node
 270          */
 271         function item( $i );
 272
 273         /**
 274          * Get the name of this node. The following names are defined here:
 275          *
 276          *    h             A heading node.
 277          *    template      A double-brace node.
 278          *    tplarg        A triple-brace node.
 279          *    title         The first argument to a template or tplarg node.
 280          *    part          Subsequent arguments to a template or tplarg node.
 281          *    #nodelist     An array-type node
 282          *
 283          * The subclass may define various other names for tree and leaf nodes.
 284          */
 285         function getName();
 286
 287         /**
 288          * Split a "<part>" node into an associative array containing:
 289          *    name          PPNode name
 290          *    index         String index
 291          *    value         PPNode value
 292          */
 293         function splitArg();
 294
 295         /**
 296          * Split an "<ext>" node into an associative array containing name, attr, inner and close
 297          * All values in the resulting array are PPNodes. Inner and close are optional.
 298          */
 299         function splitExt();
 300
 301         /**
 302          * Split an "<h>" node
 303          */
 304         function splitHeading();
 305 }