古怪的javascript php实现用php数据替换js中的数据回车中断javascript

Question

I'm working on someone elses legacy code and they have a weird implementation where they do the following:

- load javascript file into php
- perform a string replace for variables, such as replacing `$intro` with mysql data in the javascript

My problem is that the $intro data contains carriage returns so when I perform the string replace into the javascript with the mysql data it causes the javascript to break.

Here is the line of code in javascript:

 dialog.i_intro.value="$intro";

And here is the line of code in php:

$ln=str_replace("\$intro",$intro,$ln);

And here is the data:

 dialog.i_intro.value = "Hello World
 Hello World
 Hello World";

How do I resolve this?

UPDATE I need the carriage returns in the javascript

Im trying the following:

In php:

$intro = str_replace("
","--carriage--",$intro);

In Javascript:

dialog.i_intro.value=dialog.i_intro.value.replace('--carriage--','
');

But something isn't working with this.

EXTENDED UPDATE

I've replaced all line breaks with html breaks. I discovered that the code is interpreting the js using eval. Here is my current javascript output of the intro variable.

dialog.i_intro.value="Hi Im Jonathan<br />
<br />
Hi Im Jonathan<br />
<br />
Hi Im Jonathan";

What should I do next?

Answer 1

Javascript (at least currently deployed javascript in browsers, it should be easier in ES6) doesn't handle line endings in strings very intuitively. Your best bet is to escape the carriage returns, as in

 dialog.i_intro.value = "Hello World \
 Hello World \
 Hello World";

That should not trigger an error and will preserve the line breaks you require.

To implement, try this instead of your current PHP string replacement line:

$intro = str_replace("
"," \\
",$intro);