Allow customization of LaTeX math environment

README.md

@@ -156,6 +156,18 @@ To disable a link on a reference, set `nolink=True` in the reference's attribute
     @eq:id{nolink=True}
 
 
+### Custom Environments ###
+
+The default LaTeX environment may be overridden by adding an `env` attribute:
+
+    $$ y = mx + b $$ {#eq:id env=multiline}
+
+The `env` attribute must be a valid amsmath environment.
+If the attribute value is of the form `foo.bar`, `foo` will be used
+as the name of the amsmath environment and `bar` will be used as an extra argument
+for the environment (e.g. alignat expects an argument for the number of equation columns).
+
+
 Customization
 -------------
 
@@ -203,6 +215,9 @@ Pandoc-eqnos may be customized by setting variables in the [metadata block] or o
     set to the same integer value.  For LaTeX/PDF, this option
     offsets the actual section numbers as required.
 
+  * `eqnos-default-env` - Name of the default LaTeX environment
+    (default: 'equation').
+
 Note that variables beginning with `eqnos-` apply to only pandoc-eqnos, whereas variables beginning with `xnos-` apply to all of the pandoc-fignos/eqnos/tablenos/secnos.
 
 Demonstration: Processing [demo3.md] with pandoc + pandoc-eqnos gives numbered equations and references in [pdf][pdf3], [tex][tex3], [html][html3], [epub][epub3], [docx][docx3] and other formats.

pandoc_eqnos.py

@@ -71,6 +71,7 @@
 secoffset = 0           # Section number offset
 eqref = False           # Flags that \eqref should be used
 warninglevel = 2        # 0 - no warnings; 1 - some warnings; 2 - all warnings
+default_env = 'equation'
 
 # Processing state variables
 cursec = None    # Current section
@@ -186,8 +187,19 @@ def _add_markup(fmt, eq, value):
     if eq['is_unnumbered']:  # Unnumbered is also unreferenceable
         ret = None
     elif fmt in ['latex', 'beamer']:
+        if 'env' in attrs:
+            env = attrs['env']
+        else:
+            env = default_env
+
+        splitted = env.split('.')
+        env = splitted[0]
+        arg = ''
+        if len(splitted) > 1:
+            arg = '{%s}' % splitted[1]
+
         ret = RawInline('tex',
-                        r'\begin{equation}%s\end{equation}'%value[-1])
+                        r'\begin{%s}%s%s\end{%s}'% (env, arg, value[-1], env))
     elif fmt in ('html', 'html4', 'html5', 'epub', 'epub2', 'epub3') and \
       LABEL_PATTERN.match(attrs.id):
         # Present equation and its number in a span
@@ -300,7 +312,8 @@ def process(meta):
                  'eqnos-plus-name', 'eqnos-star-name',
                  'eqnos-number-by-section', 'xnos-number-by-section',
                  'xnos-number-offset',
-                 'eqnos-eqref']
+                 'eqnos-eqref',
+                 'eqnos-default-env']
 
     if warninglevel:
         for name in meta:
@@ -366,6 +379,9 @@ def process(meta):
         if eqref:  # Eqref and cleveref are mutually exclusive
             cleveref = False
 
+    if 'eqnos-default-env' in meta:
+        default_env = get_meta(meta, 'eqnos-default-env')
+
 def add_tex(meta):
     """Adds tex to the meta data."""