如何产生 <p id=“r1_c1”> 用红宝石插值？

Question

I have a need to generate an html id using some .erb code. Specifically, I want to use the row and column index of a cell in a rectangular array (made out of a table of cells). I have a method cell.web_id, which constructs a string thus:

"r#{row_index}_c#{column_index}", 

so that cell(2,3) would yield

"r2_c3".  

So far, so good.

Now for the odd part. I haven't figured out how to wrap the web_id result in double quotes required to properly define the attribute. No matter what I try, I always get:

<span class="cell" id=&quot;r1_c1&quot; >

This form doesn't work.

So, how can I get this form:

<span class="cell" id="r2_c3" >

I know this is easy if you know the proper incantation, but I don't have it.

Answer 1

Try this:

<span class="cell" id="<%="r#{row_index}_c#{column_index}"%>" >

OR

<span class="cell" id="r<%=row_index%>_c<%=column_index%>" >

OR

<span class="cell" id="<%=foo_span_id(row_index, column_index)%>" >

Where foo_span_id is a custom helper method

Answer 2

"\\"r#{row_index}_c#{column_index}\\"".html_safe

（apidock文档） （通常无用，但出于完整性考虑而包括在内）

Answer 3

Instead double quotes, why don't you try single quotes? (that is normally what I do in situations like this).

So your code will be

"'r#{row_index}_c#{column_index}'"

and your HTML will also need to be slightly changed to single quotes

<span class='cell' id='r2_c3'; >