SSViewer_Scope::next() - Code Metrics - Inspection of "Further work on Loz’ solution" - sminnee/silverstripe-framework - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — generators ( d5c396...b04334 )

by Sam

created 2017-06-28 23:19 UTC

SSViewer_Scope::next() B

↳ Parent: SSViewer_Scope

Complexity

Conditions	6
Paths	11

Size

Total Lines	43
Code Lines	22

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	6
eloc	22
nc	11
nop	0
dl	0
loc	43
rs	8.439
c	0
b	0
f	0

<?php

namespace SilverStripe\View;

use ArrayIterator;
use Countable;
use Iterator;

/**
 * This tracks the current scope for an SSViewer instance. It has three goals:
 *   - Handle entering & leaving sub-scopes in loops and withs
 *   - Track Up and Top
 *   - (As a side effect) Inject data that needs to be available globally (used to live in ViewableData)
 *
 * In order to handle up, rather than tracking it using a tree, which would involve constructing new objects
 * for each step, we use indexes into the itemStack (which already has to exist).
 *
 * Each item has three indexes associated with it
 *
 *   - Pop. Which item should become the scope once the current scope is popped out of
 *   - Up. Which item is up from this item
 *   - Current. Which item is the first time this object has appeared in the stack
 *
 * We also keep the index of the current starting point for lookups. A lookup is a sequence of obj calls -
 * when in a loop or with tag the end result becomes the new scope, but for injections, we throw away the lookup
 * and revert back to the original scope once we've got the value we're after
 */
class SSViewer_Scope
{

    const ITEM = 0;
    const ITEM_ITERATOR = 1;
    const ITEM_ITERATOR_TOTAL = 2;
    const POP_INDEX = 3;
    const UP_INDEX = 4;
    const CURRENT_INDEX = 5;
    const ITEM_OVERLAY = 6;

    // The stack of previous "global" items
    // An indexed array of item, item iterator, item iterator total, pop index, up index, current index & parent overlay
    private $itemStack = array();

    /**
     * The current "global" item (the one any lookup starts from)
     */
    protected $item;

    /**
     * If we're looping over the current "global" item, here's the iterator that tracks with item we're up to
     *
     * @var Iterator
     */
    protected $itemIterator;

    //Total number of items in the iterator
    protected $itemIteratorTotal;

    // A pointer into the item stack for which item should be scope on the next pop call
    private $popIndex;

    // A pointer into the item stack for which item is "up" from this one
    private $upIndex = null;

    // A pointer into the item stack for which item is this one (or null if not in stack yet)
    private $currentIndex = null;

    private $localIndex;

    public function __construct($item, $inheritedScope = null)
    {
        $this->item = $item;
        $this->localIndex = 0;
        $this->localStack = array();
class MyClass { }

$x = new MyClass();
$x->foo = true;
        if ($inheritedScope instanceof SSViewer_Scope) {
            $this->itemIterator = $inheritedScope->itemIterator;
            $this->itemIteratorTotal = $inheritedScope->itemIteratorTotal;
            $this->itemStack[] = array($this->item, $this->itemIterator, $this->itemIteratorTotal, null, null, 0);
        } else {
            $this->itemStack[] = array($this->item, null, 0, null, null, 0);
        }
    }

    public function getItem()
    {
        return $this->itemIterator ? $this->itemIterator->current() : $this->item;
    }

    /** Called at the start of every lookup chain by SSTemplateParser to indicate a new lookup from local scope */
    public function locally()
    {
        list($this->item, $this->itemIterator, $this->itemIteratorTotal, $this->popIndex, $this->upIndex,
            $this->currentIndex) = $this->itemStack[$this->localIndex];

        // Remember any  un-completed (resetLocalScope hasn't been called) lookup chain. Even if there isn't an
        // un-completed chain we need to store an empty item, as resetLocalScope doesn't know the difference later
        $this->localStack[] = array_splice($this->itemStack, $this->localIndex + 1);

        return $this;
    }

    public function resetLocalScope()
    {
        $previousLocalState = $this->localStack ? array_pop($this->localStack) : null;

        array_splice($this->itemStack, $this->localIndex + 1, count($this->itemStack), $previousLocalState);

        list($this->item, $this->itemIterator, $this->itemIteratorTotal, $this->popIndex, $this->upIndex,
            $this->currentIndex) = end($this->itemStack);
    }

    public function getObj($name, $arguments = [], $cache = false, $cacheName = null)
    {
        $on = $this->itemIterator ? $this->itemIterator->current() : $this->item;
        return $on->obj($name, $arguments, $cache, $cacheName);
    }

    /**
     * @param string $name
     * @param array $arguments
     * @param bool $cache
     * @param string $cacheName
     * @return $this
     */
    public function obj($name, $arguments = [], $cache = false, $cacheName = null)
    {
        switch ($name) {
            case 'Up':
                if ($this->upIndex === null) {
                    user_error('Up called when we\'re already at the top of the scope', E_USER_ERROR);
                }

                list($this->item, $this->itemIterator, $this->itemIteratorTotal, $unused2, $this->upIndex,
<?php

function returnThreeValues() {
    return array('a', 'b', 'c');
}

list($a, $b, $c) = returnThreeValues();

print $a . " - " . $c;
                    $this->currentIndex) = $this->itemStack[$this->upIndex];
                break;

            case 'Top':
                list($this->item, $this->itemIterator, $this->itemIteratorTotal, $unused2, $this->upIndex,
<?php

function returnThreeValues() {
    return array('a', 'b', 'c');
}

list($a, $b, $c) = returnThreeValues();

print $a . " - " . $c;
                    $this->currentIndex) = $this->itemStack[0];
                break;

            default:
                $this->item = $this->getObj($name, $arguments, $cache, $cacheName);
                $this->itemIterator = null;
                $this->upIndex = $this->currentIndex ? $this->currentIndex : count($this->itemStack) - 1;
                $this->currentIndex = count($this->itemStack);
                break;
        }

        $this->itemStack[] = array(
            $this->item,
            $this->itemIterator,
            $this->itemIteratorTotal,
            null,
            $this->upIndex,
            $this->currentIndex
        );
        return $this;
    }

    /**
     * Gets the current object and resets the scope.
     *
     * @return object
     */
    public function self()
    {
        $result = $this->itemIterator ? $this->itemIterator->current() : $this->item;
        $this->resetLocalScope();

        return $result;
    }

    public function pushScope()
    {
        $newLocalIndex = count($this->itemStack) - 1;

        $this->popIndex = $this->itemStack[$newLocalIndex][SSViewer_Scope::POP_INDEX] = $this->localIndex;
        $this->localIndex = $newLocalIndex;

        // We normally keep any previous itemIterator around, so local $Up calls reference the right element. But
        // once we enter a new global scope, we need to make sure we use a new one
        $this->itemIterator = $this->itemStack[$newLocalIndex][SSViewer_Scope::ITEM_ITERATOR] = null;

        return $this;
    }

    public function popScope()
    {
        $this->localIndex = $this->popIndex;
        $this->resetLocalScope();

        return $this;
    }

    public function next()
    {
        if (!$this->item) {
            return false;
        }

        if (!$this->itemIterator) {
            // Note: it is important that getIterator() is called before count() as implemenations may rely on
            // this to efficiency get both the number of records and an iterator (e.g. DataList does this)

            // Item may be an array or a regular IteratorAggregate
            if (is_array($this->item)) {
                $this->itemIterator = new ArrayIterator($this->item);
            } else {
                $this->itemIterator = $this->item->getIterator();

                // This will execute code in a generator up to the first yield. For example, this ensures that
                // DataList::getIterator() is called before Datalist::count()
                $this->itemIterator->rewind();
            }

            // If the item implements Countable, use that to fetch the count, otherwise we have to inspect the
            // iterator and then rewind it.
            if ($this->item instanceof Countable) {
                $this->itemIteratorTotal = count($this->item);
            } else {
                $this->itemIteratorTotal = iterator_count($this->itemIterator);
                $this->itemIterator->rewind();
            }

            $this->itemStack[$this->localIndex][SSViewer_Scope::ITEM_ITERATOR] = $this->itemIterator;
            $this->itemStack[$this->localIndex][SSViewer_Scope::ITEM_ITERATOR_TOTAL] = $this->itemIteratorTotal;
        } else {
            $this->itemIterator->next();
        }

        $this->resetLocalScope();

        if (!$this->itemIterator->valid()) {
            return false;
        }
        return $this->itemIterator->key();
    }

    public function __call($name, $arguments)
    {
        $on = $this->itemIterator ? $this->itemIterator->current() : $this->item;
        $retval = $on ? call_user_func_array(array($on, $name), $arguments) : null;

        $this->resetLocalScope();
        return $retval;
    }

    /**
     * @return array
     */
    protected function getItemStack()
    {
        return $this->itemStack;
    }

    /**
     * @param array
     */
    protected function setItemStack(array $stack)
    {
        $this->itemStack = $stack;
    }

    /**
     * @return int|null
     */
    protected function getUpIndex()
    {
        return $this->upIndex;
    }
}


1			<?php
2
3			namespace SilverStripe\View;
4
5			use ArrayIterator;
6			use Countable;
7			use Iterator;
8
9			/**
10			* This tracks the current scope for an SSViewer instance. It has three goals:
11			* - Handle entering & leaving sub-scopes in loops and withs
12			* - Track Up and Top
13			* - (As a side effect) Inject data that needs to be available globally (used to live in ViewableData)
14			*
15			* In order to handle up, rather than tracking it using a tree, which would involve constructing new objects
16			* for each step, we use indexes into the itemStack (which already has to exist).
17			*
18			* Each item has three indexes associated with it
19			*
20			* - Pop. Which item should become the scope once the current scope is popped out of
21			* - Up. Which item is up from this item
22			* - Current. Which item is the first time this object has appeared in the stack
23			*
24			* We also keep the index of the current starting point for lookups. A lookup is a sequence of obj calls -
25			* when in a loop or with tag the end result becomes the new scope, but for injections, we throw away the lookup
26			* and revert back to the original scope once we've got the value we're after
27			*/
28			class SSViewer_Scope
29			{
30
31			const ITEM = 0;
32			const ITEM_ITERATOR = 1;
33			const ITEM_ITERATOR_TOTAL = 2;
34			const POP_INDEX = 3;
35			const UP_INDEX = 4;
36			const CURRENT_INDEX = 5;
37			const ITEM_OVERLAY = 6;
38
39			// The stack of previous "global" items
40			// An indexed array of item, item iterator, item iterator total, pop index, up index, current index & parent overlay
41			private $itemStack = array();
42
43			/**
44			* The current "global" item (the one any lookup starts from)
45			*/
46			protected $item;
47
48			/**
49			* If we're looping over the current "global" item, here's the iterator that tracks with item we're up to
50			*
51			* @var Iterator
52			*/
53			protected $itemIterator;
54
55			//Total number of items in the iterator
56			protected $itemIteratorTotal;
57
58			// A pointer into the item stack for which item should be scope on the next pop call
59			private $popIndex;
60
61			// A pointer into the item stack for which item is "up" from this one
62			private $upIndex = null;
63
64			// A pointer into the item stack for which item is this one (or null if not in stack yet)
65			private $currentIndex = null;
66
67			private $localIndex;
68
69			public function __construct($item, $inheritedScope = null)
70			{
71			$this->item = $item;
72			$this->localIndex = 0;
73			$this->localStack = array();
			0 ignored issues – show Bug introduced 2016-09-09 23:25 UTC by Report Bug Copy Issue Report The property `localStack` does not exist. Did you maybe forget to declare it? In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code: class MyClass { } $x = new MyClass(); $x->foo = true; Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: class MyClass { public $foo; } $x = new MyClass(); $x->foo = true; Loading history...
74			if ($inheritedScope instanceof SSViewer_Scope) {
75			$this->itemIterator = $inheritedScope->itemIterator;
76			$this->itemIteratorTotal = $inheritedScope->itemIteratorTotal;
77			$this->itemStack[] = array($this->item, $this->itemIterator, $this->itemIteratorTotal, null, null, 0);
78			} else {
79			$this->itemStack[] = array($this->item, null, 0, null, null, 0);
80			}
81			}
82
83			public function getItem()
84			{
85			return $this->itemIterator ? $this->itemIterator->current() : $this->item;
86			}
87
88			/** Called at the start of every lookup chain by SSTemplateParser to indicate a new lookup from local scope */
89			public function locally()
90			{
91			list($this->item, $this->itemIterator, $this->itemIteratorTotal, $this->popIndex, $this->upIndex,
92			$this->currentIndex) = $this->itemStack[$this->localIndex];
93
94			// Remember any un-completed (resetLocalScope hasn't been called) lookup chain. Even if there isn't an
95			// un-completed chain we need to store an empty item, as resetLocalScope doesn't know the difference later
96			$this->localStack[] = array_splice($this->itemStack, $this->localIndex + 1);
97
98			return $this;
99			}
100
101			public function resetLocalScope()
102			{
103			$previousLocalState = $this->localStack ? array_pop($this->localStack) : null;
104
105			array_splice($this->itemStack, $this->localIndex + 1, count($this->itemStack), $previousLocalState);
106
107			list($this->item, $this->itemIterator, $this->itemIteratorTotal, $this->popIndex, $this->upIndex,
108			$this->currentIndex) = end($this->itemStack);
109			}
110
111			public function getObj($name, $arguments = [], $cache = false, $cacheName = null)
112			{
113			$on = $this->itemIterator ? $this->itemIterator->current() : $this->item;
114			return $on->obj($name, $arguments, $cache, $cacheName);
115			}
116
117			/**
118			* @param string $name
119			* @param array $arguments
120			* @param bool $cache
121			* @param string $cacheName
122			* @return $this
123			*/
124			public function obj($name, $arguments = [], $cache = false, $cacheName = null)
125			{
126			switch ($name) {
127			case 'Up':
128			if ($this->upIndex === null) {
129			user_error('Up called when we\'re already at the top of the scope', E_USER_ERROR);
130			}
131
132			list($this->item, $this->itemIterator, $this->itemIteratorTotal, $unused2, $this->upIndex,
			0 ignored issues – show Unused Code introduced 2016-09-09 23:25 UTC by Report Bug Copy Issue Report The assignment to `$unused2` is unused. Consider omitting it like so `list($first,,$third)`. This checks looks for assignemnts to variables using the `list(...)` function, where not all assigned variables are subsequently used. Consider the following code example. <?php function returnThreeValues() { return array('a', 'b', 'c'); } list($a, $b, $c) = returnThreeValues(); print $a . " - " . $c; Only the variables `$a` and `$c` are used. There was no need to assign `$b`. Instead, the list call could have been. list($a,, $c) = returnThreeValues(); Loading history...
133			$this->currentIndex) = $this->itemStack[$this->upIndex];
134			break;
135
136			case 'Top':
137			list($this->item, $this->itemIterator, $this->itemIteratorTotal, $unused2, $this->upIndex,
			0 ignored issues – show Unused Code introduced 2016-09-09 23:25 UTC by Report Bug Copy Issue Report The assignment to `$unused2` is unused. Consider omitting it like so `list($first,,$third)`. This checks looks for assignemnts to variables using the `list(...)` function, where not all assigned variables are subsequently used. Consider the following code example. <?php function returnThreeValues() { return array('a', 'b', 'c'); } list($a, $b, $c) = returnThreeValues(); print $a . " - " . $c; Only the variables `$a` and `$c` are used. There was no need to assign `$b`. Instead, the list call could have been. list($a,, $c) = returnThreeValues(); Loading history...
138			$this->currentIndex) = $this->itemStack[0];
139			break;
140
141			default:
142			$this->item = $this->getObj($name, $arguments, $cache, $cacheName);
143			$this->itemIterator = null;
144			$this->upIndex = $this->currentIndex ? $this->currentIndex : count($this->itemStack) - 1;
145			$this->currentIndex = count($this->itemStack);
146			break;
147			}
148
149			$this->itemStack[] = array(
150			$this->item,
151			$this->itemIterator,
152			$this->itemIteratorTotal,
153			null,
154			$this->upIndex,
155			$this->currentIndex
156			);
157			return $this;
158			}
159
160			/**
161			* Gets the current object and resets the scope.
162			*
163			* @return object
164			*/
165			public function self()
166			{
167			$result = $this->itemIterator ? $this->itemIterator->current() : $this->item;
168			$this->resetLocalScope();
169
170			return $result;
171			}
172
173			public function pushScope()
174			{
175			$newLocalIndex = count($this->itemStack) - 1;
176
177			$this->popIndex = $this->itemStack[$newLocalIndex][SSViewer_Scope::POP_INDEX] = $this->localIndex;
178			$this->localIndex = $newLocalIndex;
179
180			// We normally keep any previous itemIterator around, so local $Up calls reference the right element. But
181			// once we enter a new global scope, we need to make sure we use a new one
182			$this->itemIterator = $this->itemStack[$newLocalIndex][SSViewer_Scope::ITEM_ITERATOR] = null;
183
184			return $this;
185			}
186
187			public function popScope()
188			{
189			$this->localIndex = $this->popIndex;
190			$this->resetLocalScope();
191
192			return $this;
193			}
194
195			public function next()
196			{
197			if (!$this->item) {
198			return false;
199			}
200
201			if (!$this->itemIterator) {
202			// Note: it is important that getIterator() is called before count() as implemenations may rely on
203			// this to efficiency get both the number of records and an iterator (e.g. DataList does this)
204
205			// Item may be an array or a regular IteratorAggregate
206			if (is_array($this->item)) {
207			$this->itemIterator = new ArrayIterator($this->item);
208			} else {
209			$this->itemIterator = $this->item->getIterator();
210
211			// This will execute code in a generator up to the first yield. For example, this ensures that
212			// DataList::getIterator() is called before Datalist::count()
213			$this->itemIterator->rewind();
214			}
215
216			// If the item implements Countable, use that to fetch the count, otherwise we have to inspect the
217			// iterator and then rewind it.
218			if ($this->item instanceof Countable) {
219			$this->itemIteratorTotal = count($this->item);
220			} else {
221			$this->itemIteratorTotal = iterator_count($this->itemIterator);
222			$this->itemIterator->rewind();
223			}
224
225			$this->itemStack[$this->localIndex][SSViewer_Scope::ITEM_ITERATOR] = $this->itemIterator;
226			$this->itemStack[$this->localIndex][SSViewer_Scope::ITEM_ITERATOR_TOTAL] = $this->itemIteratorTotal;
227			} else {
228			$this->itemIterator->next();
229			}
230
231			$this->resetLocalScope();
232
233			if (!$this->itemIterator->valid()) {
234			return false;
235			}
236			return $this->itemIterator->key();
237			}
238
239			public function __call($name, $arguments)
240			{
241			$on = $this->itemIterator ? $this->itemIterator->current() : $this->item;
242			$retval = $on ? call_user_func_array(array($on, $name), $arguments) : null;
243
244			$this->resetLocalScope();
245			return $retval;
246			}
247
248			/**
249			* @return array
250			*/
251			protected function getItemStack()
252			{
253			return $this->itemStack;
254			}
255
256			/**
257			* @param array
258			*/
259			protected function setItemStack(array $stack)
260			{
261			$this->itemStack = $stack;
262			}
263
264			/**
265			* @return int\|null
266			*/
267			protected function getUpIndex()
268			{
269			return $this->upIndex;
270			}
271			}
272

sminnee / silverstripe-framework

Push — generators ( d5c396...b04334 )

SSViewer_Scope::next() B

Complexity

Size

Duplication

Importance

Duplication Side-by-Side

Filter issues like