在 PHP 中，如何折叠 heredoc（此处文档）中的换行符？

Question

出于 CLI 的目的，我想部分在heredoc（此处的文档）内折叠（忽略换行符）。

目前，我在要折叠的行末尾使用%%，然后使用str_replace("%%\n",'', $string); 替换它们。但我觉得不太舒服。

有什么逃生绳或更聪明的方法吗？

例如：

<?php

$string=<<<EOL
This is a single long line, and it has to be
in one line, though the SideCI thing (as a 
coding regulation) I have to line break.
But this line stays short.
And this line too.
And the backslash such as \
won't work. Nor /
won't work.
My alternative way is to use %%
strings and replace them later.

EOL;

$string .= 'And I don\'t want to do this ';
$string .= 'to merge strings.';

echo str_replace("%%\n",'', $string);

我得到如下：

This is a single long line, and it has to be
in one line, though the SideCI thing (as a 
coding regulation) I have to line break.
But this line stays short.
And this line too.
And the backslash such as \
won't work. Nor /
won't work.
My alternative way is to use strings and replace them later.
And I don't want to do this to merge strings.

有什么想法吗？

---

目前的结论（2018/01/17）

禁用换行符作为默认行为，并使用BR 标记代替换行符。
1. 将PHP_EOL（换行符）替换为''（空白）。
2.将BR标签替换为PHP_EOL。

示例代码：

<?php

$string=<<<EOL
This is a single long line, and it has to be
in one line, though the SideCI thing (as a 
coding regulation) I have to line break.<br>
But this line stays short.<br>
And this line too.<br>
My post alternative way was to use %%
chars and replace them later.<br>

EOL;

$string = str_replace(PHP_EOL,'', $string);
$string = str_ireplace(["<br />","<br>","<br/>"], PHP_EOL, $string);

echo $string;

Answer 1

您可以通过修改使用<br> 标记的HTML 标准来说明何时确实需要换行符。对于习惯使用 HTML 的人来说，这会感觉更直观...

$string=<<<EOL
This is a single long line, and it has to be
in one line, though the SideCI thing (as a
coding regulation) I have to line break.
But this line stays short.
And this line too.
And the backslash such as \<br>
won't work. Nor /<br>
won't work.<br>
My alternative way is to use %%<br>
strings and replace them later.

EOL;

$string = str_replace(PHP_EOL,'', $string);
$string = str_ireplace(["<br />","<br>","<br/>"], PHP_EOL, $string);
echo $string;

注意使用PHP_EOL 来使用新行/换行符的正确当前编码或您使用的平台所具有的任何组合。

Answer 2

我个人会使用{nbr} 之类的东西，只是因为%% 似乎太通用了，其中{nbr} 是“不中断”，而{...} 在模板中很常见，这只是一种意见。

但我也会使用 regx 而不是 str_replace

preg_replace('/{nbr}[\r\n]+/', '', $str);

这样它匹配 \r、\r\n、\n 甚至 \n\n 或旧 Mac、Windows、Linux 和多行结尾。

你可以看到it here: