mjhjmtu

At a certain position in the article, the page that it belongs, need a special fancy style which I do by thispagestyle from the package fancyhdr.

In my example as shown in the MWE below, the page, and only the page where the text "bbb" is in(it's at the second page in this example, but may also at the other page, determined by the length of article), need a chead. However, the content of chead is in fact at the first page, not in the second page as I expect.

I think this is because no page-break is given. But the position of text "bbb" is up to the length of article, so how to deal with this problem?

My MWE is:

documentclassarticle
usepackagefancyhdr

begindocument
fancypagestylecommoncheadI want my header only on the page at which ``bbb'' is located
aaaparvspace80em
bbbthispagestylecommonparvspace80em
ccc
enddocument

EDIT:

To make my intention more clearly, I'd like to give the following modified MWE.

My desire is: all pages should have the same header/footer contents which are defined in fancypagestyleallpages, except that the page which "bbb" is in(in this example,it's the second page), has a different header/footer defined by fancypagestyleonlythispage.

But the real typeset is far from my intention. I think this is because no page-breaks are given.

As the position of "bbb" is up to the length of article, I can't forsee which page it will be in. So, is there an unvesal method to deal with such kind of problem?

documentclassarticle
usepackagefancyhdr,

begindocument

fancypagestyleonlythispagecheadonly this pagecfootonly this page
fancypagestyleallpagesfancyhfcheadall pagescfootall pages

pagestyleallpages

aaaparvspace80em
bbbthispagestyleonlythispageparvspace80em
ccc
enddocument

You can use a mark command:

documentclassarticle
usepackagefancyhdr
fancypagestylecommonfancyhfcheadrightmark
pagestylecommon
begindocument

aaaparvspace80em
bbbmarkrightI want my header only on the page at which ``bbb'' is locatedmarkrightparvspace80em
ccc
enddocument

You can also pass a boolean with the mark command use this in the header. The value of the first markright on the page will win.

documentclassarticle
usepackagefancyhdr
usepackageetoolbox
newboolbbbpage

begindocument

fancypagestyleallpagesfancyhf%
 cheadrightmarkifboolbbbpageonly this pageall pages
 cfootrightmarkifboolbbbpageonly this pageall pages

pagestyleallpages

aaaparvspace80em
bbbmarkrightbooltruebbbpagemarkrightboolfalsebbbpageparvspace80em
ccc
enddocument

In case you need markright/rightmark, e.g. to get some section
on the headers, you could use your own marks (but this could break e.g. with twocolumn or multicolumn).

I guess you're using headers, but that's not really relevant.

The problem is that page breaking is asynchronous: typically TeX reads more that fits in a page before deciding it has to ship out a page. In your case, thispagestyle is seen and processed while TeX has not yet decided to eject page 1.

The command thispagestyle is only reliable if given shortly after a page break, for instance when a new chapter is started, a feature which standard classes use for issuing thispagestyleplain.

The only reliable method is to use the label-pageref mechanism. Here I implement the job with the help of refcount that provides an expandable version of pageref, namely getpagerefnumber.

documentclassarticle
usepackagefancyhdr
usepackagerefcount,pdftexcmds

pagestylefancy

makeatletter
chead%
 ifnumpdf@strcmpthepagegetpagerefnumberbbb=z@
 I want my header only on the page at which ``bbb'' is located%
 else
 Normal header%
 fi

makeatother

begindocument

aaaparvspace80em
bbblabelbbbparvspace80em
ccc

enddocument

I use pdf@strcmp in order to ensure that any kind of page numbering is supported.

The following supports any number of variant headers. Please, don't dare to ask for a version without ExplSyntaxOn.

The alternate headers are collected in a property list, indexed by the labels we want to use. At begin document, this property list is reindexed using the page number corresponding to the reference. Due to this, later appearing labels will take precedence in case two labels for alternate headers happen to fall on the same page.

documentclassarticle
usepackage[a6paper]geometry % just to make a smaller picture
usepackagefancyhdr
usepackagerefcount,xparse

ExplSyntaxOn
NewDocumentCommanddefinelylheadersmm
 % #1: default header
 % #2: label=alternate header, label=alternate header, ...
 tl_gset:Nn g_lylheader_default_tl #1 
 prop_gset_from_keyval:Nn g_lylheader_headers_prop #2 
 prop_map_inline:Nn g_lylheader_headers_prop
 
 seq_gput_right:Nn g_lylheaders_labels_seq ##1 
 
 

AtBeginDocument
 
 seq_map_inline:Nn g_lylheaders_labels_seq
 
 prop_gput:Nxx g_lylheaders_headers_body_prop
 getpagerefnumber#1 
 prop_item:Nn g_lylheader_headers_prop #1 
 
 

NewDocumentCommandlylheaders
 
 prop_if_in:NxTF g_lylheaders_headers_body_prop thepage 
 
 prop_item:Nx g_lylheaders_headers_body_prop thepage 
 
 
 tl_use:N g_lylheader_default_tl
 
 

cs_generate_variant:Nn prop_if_in:NnTF Nx 
cs_generate_variant:Nn prop_item:Nn Nx 
cs_generate_variant:Nn prop_gput:Nnn Nxx 

tl_new:N g_lylheader_default_tl
prop_new:N g_lylheaders_headers_prop
prop_new:N g_lylheaders_headers_body_prop
seq_new:N g_lylheaders_labels_seq

ExplSyntaxOff

pagestylefancy
cheadlylheaders

definelylheadersDefault header
 bbb = This is the header for bbb,
 ccc = This is the header for ccc,


begindocument

aaaparvspacedimexprtextheight-topskip
bbblabelbbbparvspacedimexprtextheight-topskip
ccclabelcccparvspacedimexprtextheight-topskip
ddd

enddocument