Webmaster forum - Emacs and HTML Tips

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Emacs and HTML Tips

Xah Lee

2006-09-24, 6:58 pm

Emacs and HTML Tips

Xah Lee, 2006-09-19

My website, XahLee.org, has over 3000 html pages as of today. About a
thousand pages are mirrors of Classic Literatures or manuals (e.g.
elisp manual at 850+ pages). These pages are semi-automatically
generated by scripts. The other 2000 or so pages are manually created
with emacs.

This page provides some tips about using Emacs with HTML. If you find
this page incomprehensible, please first be familiar with: Emacs
Intermediate.

In emacs, when you open a file ending in =E2=80=9Chtml=E2=80=9D, it'll
automatically open in html-mode.

First of all, put the following code in your emacs init file. (usually
at =E2=80=9C~/.emacs=E2=80=9D)

; do highlight selection
(transient-mark-mode t)

; turn on syntax highlighting
(font-lock-maximum-decoration 2)

; highlight matching parens.
(show-paren-mode t)

; when there is a selection, delete key deletes the region instead of
just a char.
(delete-selection-mode t)

Except the last one, the others can be found under the menu named
=E2=80=9COptions=E2=80=9D. If you are using the menu, be sure to also use
=E2=80=9COptions =E2=86=92 Save Options=E2=80=9D so that these are turned o=
n the next
time you start emacs.

Q: How to insert a tag?

A: html-mode provides many shortcuts to insert tags. Here's a list of
tags you can insert and their keyboard shortcuts and command names.

<h1> C-c 1 html-headline-1
<h2> C-c 2 html-headline-2
<p> C-c RET html-paragraph
<hr> C-c C-c - html-horizontal-rule
<ul> C-c C-c u html-unordered-list
<li> C-c C-c l html-list-item

For a complete list of shortcuts, do =E2=80=9CM-x html-mode=E2=80=9D, then =
=E2=80=9CC-h
m=E2=80=9D to see the list.

Q: How to close a tag?

A: Place your cursor at the place where you want to insert the closing
tag, then press =E2=80=9CC-c /=E2=80=9D.

Q: How to delete a tag?

A: Put your cursor on or inside the tag, then press C-c DEL. This will
delete both the beginning and ending tags. Very convenient.

Q: How to make the cursor jump to the end of the enclosing tag?

A: C-c C-f. Also, to move to the beginning of a tag pair, do C-c C-b.
The f is for forward, and b for backward.

Q: How to insert my custom tag?

A: Put the following code in your emacs init file. Then, can press 5 on
the keypad, and your custom tag will be inserted, and your cursor point
will be placed in between them.

(global-set-key [kp-5] 'insert-p)

(defun insert-p ()
"inserts HTML markup <p></p>."
(interactive)
(insert "<p>\n</p>")
(backward-char 5)
)

You can change the string in the above code so that it will insert
another tag that you use frequently, or even a text template, such as
headers and footers. You can also change the keyboard shortcut for
this. For example, you can have the F1, F2, F3... etc function keys
each one inserting a different tag for you.

For how to change the keyboard shortcut, see Defining Your Own Keyboard
Shortcuts.

Q: How to generate a link?

A: Press C-c C-c h (html-href-anchor). Emacs will then ask you to type
a url, then insert it with the closing =E2=80=9C</a>=E2=80=9D, with your cu=
rsor
placed before it so that you can type the link text.

Alternatively, you can place the following lisp code in your emacs init
file:

(defun wrap-url ()
"Make thing at cursor point into a html link.\n
Example: http://wikipedia.org/
becomes
<a href=3D\"http://en.wikipedia.org/\">http://wikipedia.org/</a>"
(interactive)
(re-search-backward "[\n\t ()]" nil t)
(looking-at "[\n\t ()]?\\([^\n\t ()]+\\)")
(let (
(p1 (match-beginning 1))
(p2 (match-end 1))
(url (match-string 1))
)
(delete-region p1 p2)
(goto-char p1)
(insert "<a href=3D\"" url "\">" url "</a>" )
)
)

(add-hook 'html-mode-hook
(lambda ()
(define-key html-mode-map "\M-5" 'wrap-url)
)
)

With this code, pressing M-5 will automatically make the url your
cursor is on into a link.

Q: How to do a inline image?

A: Press C-c C-c i (html-image). Alternatively, you can place the
following into your emacs init file.

(defun tag-image ()
"Replace an image file name at point with an HTML img tag.
eg: x.jpg became <img src=3D\"x.jpg\" alt=3D"" width=3D\"123\"
height=3D\"456\">."
(interactive)
(let ((imgName (thing-at-point 'filename))
(bounds (bounds-of-thing-at-point 'filename)))
(delete-region (car bounds) (cdr bounds))
(let ((image-size
(let ((ximg (create-image (concat default-directory
imgName))))
(image-size ximg t))))
(let ((width (number-to-string (car image-size)))
(height (number-to-string (cdr image-size))))
(insert "<img src=3D\"" imgName "\" "
"alt=3D\"\" "
"width=3D\"" width
"\" "
"height=3D\"" height
"\">")))))

(add-hook 'html-mode-hook
(lambda ()
(define-key html-mode-map "\M-4" 'tag-image)
)
)

With this code, pressing M-4 while in html-mode will make the url or
relative path into a inline image, with =E2=80=9Calt=E2=80=9D and =E2=80=9C=
height=E2=80=9D and
=E2=80=9Cwidth=E2=80=9D attributes.

Q: How to wrap a tag around the word at the cursor point?

A: put the following in your emacs init file.

(defun wrap-text (aa bb)
"Wrap strings aa and bb around a word or region."
(interactive)
(if (and transient-mark-mode mark-active)
(let ((e1 (region-beginning)) (e2 (region-end)))
(kill-region e1 e2)
(insert aa)
(yank)
(insert bb)
)
(let ((tt (thing-at-point 'word)))
(skip-chars-backward "^ \t\n,.;?:!<>'=E2=80=98=E2=80=99=E2=80=9C=E2=
=80=9D")
(delete-char (save-excursion (skip-chars-forward "^
\t\n.,;?:!<>'=E2=80=98=E2=80=99=E2=80=9C=E2=80=9D")))
(insert aa tt bb) )
)
)

(defun wrap-span-xb ()
"Wrap a HTML span around a word or region."
(interactive)
(wrap-text "<span class=3D\"xb\">" "</span>")
)

With the above code, =E2=80=9CM-x wrap-span-xb=E2=80=9D will wrap a <span
class=3D"xb"> and </span> around the word your cursor is on. You can
change the text so that you can have different commands for tag wraps.
You can also make them into a keyboard shortcuts so that different
press of keys will wrap different tags around the word. (such as, bold,
italic, or any css class or style).

For how to define keyboard shortcuts, see Defining Your Own Keyboard
Shortcuts.

Q: How to find-replace a region with some text?

A: If you have a need to replace several pairs of characters, you can
define a lisp function that does this easy on a region. For example,
place the following in your emacs init file:

(defun replace-string-pairs-region (start end mylist)
"Replace string pairs in region."
(save-restriction
(narrow-to-region start end)
(mapc
(lambda (arg)
(goto-char (point-min))
(while (search-forward (car arg) nil t) (replace-match (cadr
arg)) )
) mylist
)
)
)

(defun replace-greek (start end)
"Replace math symbols. e.g. alpha to =CE=B1."
(interactive "r")
(replace-string-pairs-region start end '(
("alpha" "=CE=B1")
("beta" "=CE=B2")
("gamma" "=CE=B3")
("theta" "=CE=B8")
("lambda" "=CE=BB")
("delta" "=CE=B4")
("epsilon" "=CE=B5")
("omega" "=CF=89")
("Pi" "=CF=80")
)
)
)

With the above code, you can select a region, then press M-x
replace-greek, and have all greek letter names replaced by their
letters. This will be handy when you write a lot math. You can bind
this command to a Keyboard Shortcuts for easy operation.

Also, you can change the code to make it replace other strings. For
example, the following are required:

> =E2=86=92 >
< =E2=86=92 <
& =E2=86=92 &

The following, changing html entities to actual unicode characters
makes the html source code more elegant and readible.

“ =E2=86=92 =E2=80=9C
” =E2=86=92 =E2=80=9D
é =E2=86=92 =C3=A9
© =E2=86=92 =C2=A9

Q: How to switch to browser and preview?

A: In html-mode, do C-c C-v. You can also get a textual preview by
pressing C-c TAB, which will hide all the tags. Press C-c TAB again to
show tags.

----
This post is archived at:
http://xahlee.org/emacs/emacs_html.html

Xah
xah@xahlee.org
=E2=88=91 http://xahlee.org/

Viper

2006-09-24, 6:58 pm

XXXX off

Jesse Alama

2006-09-24, 6:58 pm

"Viper" <venomx@XXXXXXXXXX> writes:

> XXXX off

Well that's not very polite, is it?

Jesse

--
Jesse Alama (alama@stanford.edu)

Jerry Stuckle

2006-09-24, 6:58 pm

Xah Lee wrote:
> Emacs and HTML Tips
>

Who cares about Emacs?

Show me how I can do this nifty stuff in edlin!

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attglobal.net
==================

Baho Utot

2006-09-24, 6:58 pm

Jerry Stuckle wrote:

>
>
> Xah Lee wrote:
>
> Who cares about Emacs?
>
> Show me how I can do this nifty stuff in edlin!
>

what about in vi and vim?

--
Dancin' in the ruins tonight
Tayo'y Mga Pinoy

William Tasso

2006-09-24, 6:58 pm

Fleeing from the madness of the Road Runner High Speed Online
http://www.rr.com jungle
Baho Utot <baho-utot@kumusta.org> stumbled into news:comp.emacs
and said:

> Jerry Stuckle wrote:

/waves
[color=darkred]
>
> what about in vi

note to self: really must make time to sit down with a tutorial on this.

> and vim?

and vigour?

--
William Tasso

http://williamtasso.com/words/what-is-usenet.asp

Toby Inkster

2006-09-24, 6:59 pm

Xah Lee wrote:

> My website, XahLee.org, has over 3000 html pages as of today.

Argh!!!

> These pages are semi-automatically generated by scripts.

Phew!

> The other 2000 or so pages are manually created with emacs.

Double Argh!!!

If you can generate 1000 pages semi-automatically, why not the other 2000?

2000 pages is far too many to manage manually. Persoanlly, I wouldn't
manage any more that four pages manually -- any more than that and I'd use
a CMS (even if the "S" is just a small home-grown PERL pre-processor).

And dude, save your sanity and use vim imstead of emacs.

<ducks and runs> ;-)

--
Toby A Inkster BSc (Hons) ARCS
Contact Me ~ http://tobyinkster.co.uk/contact

justinhj

2006-09-24, 6:59 pm

This is a fantastic resource, I could spend all day on here Xah Lee.

Justin