# Lists 循环

lists 标签主要用于在模板中循环输出数据集或者多维数组。

# 普通输出

lists 标签的 name 属性表示模板赋值的变量名称,因此不可随意在模板文件中改变。 id 表示当前的循环变量,可以随意指定,但确保不要和 name 属性冲突。

public function testBaseUse(): void
{
    $parser = $this->createParser();

    $source = <<<'eot'
        <lists name="list" id="vo">
            {$vo.title}  {$vo.people}
        </lists>
        eot;

    $compiled = <<<'eot'
        <?php if (is_array($list)):
            $index = 0;
            $tmp = $list;
            if (0 === count($tmp)):
                echo "";
            else:
                foreach ($tmp as $key => $vo):
                    ++$index;
                    $mod = $index % 2; ?>
            <?php echo $vo->title; ?>  <?php echo $vo->people; ?>
                <?php endforeach;
            endif;
        else:
            echo "";
        endif; ?>
        eot;

    $this->assertSame($compiled, $parser->doCompile($source, null, true));
}

# 部分输出指定开始位置和长度的记录

支持输出部分数据,例如输出其中的第 2~4 条记录。

public function testOffsetLength(): void
{
    $parser = $this->createParser();

    $source = <<<'eot'
        <lists name="list" id="vo" offset="2" length='4'>
            {$vo.title} {$vo.people}
        </lists>
        eot;

    $compiled = <<<'eot'
        <?php if (is_array($list)):
            $index = 0;
            $tmp = array_slice($list, 2, 4);
            if (0 === count($tmp)):
                echo "";
            else:
                foreach ($tmp as $key => $vo):
                    ++$index;
                    $mod = $index % 2; ?>
            <?php echo $vo->title; ?> <?php echo $vo->people; ?>
                <?php endforeach;
            endif;
        else:
            echo "";
        endif; ?>
        eot;

    $this->assertSame($compiled, $parser->doCompile($source, null, true));
}

# 部分输出指定开始位置到结尾的所有记录

支持输出部分数据,例如输出指定开始位置到结尾的所有记录。

public function testOffset(): void
{
    $parser = $this->createParser();

    $source = <<<'eot'
        <lists name="list" id="vo" offset="3">
            {$vo.title}  {$vo.people}
        </lists>
        eot;

    $compiled = <<<'eot'
        <?php if (is_array($list)):
            $index = 0;
            $tmp = array_slice($list, 3);
            if (0 === count($tmp)):
                echo "";
            else:
                foreach ($tmp as $key => $vo):
                    ++$index;
                    $mod = $index % 2; ?>
            <?php echo $vo->title; ?>  <?php echo $vo->people; ?>
                <?php endforeach;
            endif;
        else:
            echo "";
        endif; ?>
        eot;

    $this->assertSame($compiled, $parser->doCompile($source, null, true));
}

# 输出偶数记录

lists 还支持偶数记录的输出,基于 mod 属性来控制。

public function testMod(): void
{
    $parser = $this->createParser();

    $source = <<<'eot'
        <lists name="list" id="vo" mod="2">
            <?php if ($mod == 1): ?>
                {$vo.title} {$vo.people}
            <?php endif; ?>
        </lists>
        eot;

    $compiled = <<<'eot'
        <?php if (is_array($list)):
            $index = 0;
            $tmp = $list;
            if (0 === count($tmp)):
                echo "";
            else:
                foreach ($tmp as $key => $vo):
                    ++$index;
                    $mod = $index % 2; ?>
            <?php if ($mod == 1): ?>
                <?php echo $vo->title; ?> <?php echo $vo->people; ?>
            <?php endif; ?>
                <?php endforeach;
            endif;
        else:
            echo "";
        endif; ?>
        eot;

    $this->assertSame($compiled, $parser->doCompile($source, null, true));
}

TIP

奇数记录和偶数记录规定如下,我们以数组的 0 为开始,0、2、4为偶记录,其它的都为基数记录。

# 输出奇数记录

lists 还支持奇数记录的输出,基于 mod 属性来控制。

public function testMod2(): void
{
    $parser = $this->createParser();

    $source = <<<'eot'
        <lists name="list" id="vo" mod="2">
            <?php if (0 === $mod): ?>
                {$vo.title} {$vo.people}
            <?php endif; ?>
        </lists>
        eot;

    $compiled = <<<'eot'
        <?php if (is_array($list)):
            $index = 0;
            $tmp = $list;
            if (0 === count($tmp)):
                echo "";
            else:
                foreach ($tmp as $key => $vo):
                    ++$index;
                    $mod = $index % 2; ?>
            <?php if (0 === $mod): ?>
                <?php echo $vo->title; ?> <?php echo $vo->people; ?>
            <?php endif; ?>
                <?php endforeach;
            endif;
        else:
            echo "";
        endif; ?>
        eot;

    $this->assertSame($compiled, $parser->doCompile($source, null, true));
}

TIP

奇数记录和偶数记录规定如下,我们以数组索引的 0 为开始,0、2、4 为偶数记录,1、3、5 为基数记录。

# 控制换行

mod 属性还用于控制一定记录的换行。

public function testMod3(): void
{
    $parser = $this->createParser();

    $source = <<<'eot'
        <lists name="list" id="vo" mod="2">
            {$vo.title} {$vo.people}
            <?php if (0 === $mod): ?>
                <br>
            <?php endif; ?>
        </lists>
        eot;

    $compiled = <<<'eot'
        <?php if (is_array($list)):
            $index = 0;
            $tmp = $list;
            if (0 === count($tmp)):
                echo "";
            else:
                foreach ($tmp as $key => $vo):
                    ++$index;
                    $mod = $index % 2; ?>
            <?php echo $vo->title; ?> <?php echo $vo->people; ?>
            <?php if (0 === $mod): ?>
                <br>
            <?php endif; ?>
                <?php endforeach;
            endif;
        else:
            echo "";
        endif; ?>
        eot;

    $this->assertSame($compiled, $parser->doCompile($source, null, true));
}

# mod 支持变量

mod 属性支持变量。

public function testModCanBeVar(): void
{
    $parser = $this->createParser();

    $source = <<<'eot'
        {~$mod = 4}
        
        <lists name="list" id="vo" mod="mod">
            {$vo.title}  {$vo.people}
        </lists>
        eot;

    $compiled = <<<'eot'
        <?php $mod = 4; ?>
        
        <?php if (is_array($list)):
            $index = 0;
            $tmp = $list;
            if (0 === count($tmp)):
                echo "";
            else:
                foreach ($tmp as $key => $vo):
                    ++$index;
                    $mod = $index % $mod; ?>
            <?php echo $vo->title; ?>  <?php echo $vo->people; ?>
                <?php endforeach;
            endif;
        else:
            echo "";
        endif; ?>
        eot;

    $this->assertSame($compiled, $parser->doCompile($source, null, true));
}

# 输出循环索引

public function testIndex(): void
{
    $parser = $this->createParser();

    $source = <<<'eot'
        <lists name="list" id="vo" index="k">
            {$k} {$vo.people}
        </lists>
        eot;

    $compiled = <<<'eot'
        <?php if (is_array($list)):
            $k = 0;
            $tmp = $list;
            if (0 === count($tmp)):
                echo "";
            else:
                foreach ($tmp as $key => $vo):
                    ++$k;
                    $mod = $k % 2; ?>
            <?php echo $k; ?> <?php echo $vo->people; ?>
                <?php endforeach;
            endif;
        else:
            echo "";
        endif; ?>
        eot;

    $this->assertSame($compiled, $parser->doCompile($source, null, true));
}

# 输出数组的键值

如果要输出数组的键值,可以直接使用 key 变量,和循环变量不同的是,这个 key 是由数据本身决定,而不是循环控制的,这个 key 可以通过 key 属性指定。

public function testKey(): void
{
    $parser = $this->createParser();

    $source = <<<'eot'
        <lists name="list" id="vo">
            key: {$key}
        </lists>
        eot;

    $compiled = <<<'eot'
        <?php if (is_array($list)):
            $index = 0;
            $tmp = $list;
            if (0 === count($tmp)):
                echo "";
            else:
                foreach ($tmp as $key => $vo):
                    ++$index;
                    $mod = $index % 2; ?>
            key: <?php echo $key; ?>
                <?php endforeach;
            endif;
        else:
            echo "";
        endif; ?>
        eot;

    $this->assertSame($compiled, $parser->doCompile($source, null, true));
}