Textarea line feed

When you use in-row editing in the DataGrid in easyui, the line feed of textarea is saved to the MySQL database \ n.
In textarea, input a carriage return character to read the value \ r \ n from textarea in JS, and then convert it to string at the business layer, which may become a space and be saved to the database, when this value is taken out, it will become a space, so we need to replace \ r \ n that is not displayed.

When JS retrieves textarea:

If you use

VaR STR = Document. getelementbyid ("textarea"). value;
STR = Str. Replace ("\ r \ n", "<br> ");

Then, only the first \ r \ n will be replaced with <br>. How can we replace all n \ r \ n with <br>? Is there an infinite number of replace?

Actually, no. Replace can be combined with a regular expression to replace all \ r \ n at a time.

VaR Reg = new Regexp ("\ r \ n", "G ");
STR = Str. Replace (Reg, "\ r \ n ");

In this way, all \ r \ n in STR is replaced with <br>. Then, it can be saved to the database.

You only need to replace the value after it is retrieved.

VaR Reg = new Regexp ("<br>", "G ");
STT = Str. Replace (Reg, "\ r \ n ");
Document. getelementbyid ("textarea"). value = STR;

For more detailed analysis and application, refer to the use of the replace method and regular expression in JavaScript.

Below are the two functions I have written that can be replaced after being directly put into the universal package.

Function replacetextarea1 (STR ){
VaR Reg = new Regexp ("\ r \ n", "G ");
VaR reg1 = new Regexp ("", "G ");

STR = Str. Replace (Reg, "<br> ");
STR = Str. Replace (reg1, "<p> ");

Return STR;
}

Function replacetextarea2 (STR ){
VaR Reg = new Regexp ("<br>", "G ");
VaR reg1 = new Regexp ("<p>", "G ");

STR = Str. Replace (Reg, "\ r \ n ");
STR = Str. Replace (reg1 ,"");

Return STR;
}

2. in HTML, the content submitted by the <textarea> tag will be converted into "\ r \ n" by carriage return, and the submitted content will be displayed in the <textarea> tag, the carriage return is restored to a normal line feed.

However, when a string with "\ r \ n" is displayed in a common HTML text field, the original line feed effect is converted into a space. Therefore, replace "\ r \ n" in the string with "</BR>" before display ".

In addition, note that the El expression converts "</BR>" line breaks into "& lt;/BR & gt;", "& lt;" and "& gt; "corresponds to" <"and"> ", that is, it is displayed as" </BR> "on the page (HA, El is too intelligent ), to remedy this, JSP labels (<% = %>) are used for display.

Therefore, when you need to display the content submitted by <textarea> in a common text domain, you can directly store unprocessed strings in the database, replace "\ r \ n" with "</BR>" before display, and then use <% = %> to display the content on the page.

3. If spaces and carriage returns are correctly displayed in the textbox submitted to the database
Public String myreplace (string mystr)
{
If (mystr = NULL | mystr = "")
{
Return ("& nbsp ;");
}
Else
{
Mystr = mystr. Replace ("\ n \ r", "<br> ");
Mystr = mystr. Replace ("\ r", "<br> ");
Mystr = mystr. Replace ("\ t ","");
Return (mystr );
}
}