almost working again

5 files changed, 264 insertions, 2 deletions

diff --git a/equations/models.py b/equations/models.py
index 71a8362..6791eb2 100644
--- a/equations/models.py
+++ b/equations/models.py
@@ -1,3 +1,120 @@
 from django.db import models
+from django.utils.translation import gettext_lazy as _
+import django.contrib.auth.models as auth
+from django.conf import settings
+from django.dispatch import dispatcher
+from django.db.models import signals
+from signals import update_render
 
-# Create your models here.
+class Symbol(models.Model):
+    name = models.CharField(_("Name"), maxlength=256)
+    latex = models.TextField(_("Raw LaTeX"), unique=True)
+    unicode = models.TextField(_("Unicode Representation"), blank=True)
+    renderdir = "symbolrenders/"
+    render = models.ImageField(_("Rendered Image"), 
+        upload_to=renderdir, editable=False)
+
+    class Meta:
+        get_latest_by = 'name'
+    class Admin:
+        ordering = ['name']
+
+    def __str__(self):
+        return self.name
+    def get_absolute_url(self):
+        return "/symbol/%s/" % self.id
+    def get_admin_url(self):
+        return "/admin/symbols/%s/" % self.id
+    #def save(self):
+    #    super(Symbol, self)
+    #    self.update_generic_variable()
+    def save(self):
+        super(Symbol, self).save()
+        self.render = self.renderdir + "%s.png" % self.id
+        super(Symbol, self).save()
+
+def update_generic_variable(sender, instance, signal, *args, **kwargs):
+    """Checks if there is a generic variable associated with this
+        symbol; create one if there isn't"""
+    for v in Variable.objects.filter(isgeneric=True):
+        if v.latex == instance.latex:
+            return
+    genericv = Variable(name="Generic %s" % instance.name,
+                        latex=instance.latex,
+                        unicode=instance.unicode,
+                        symbol=instance,
+                        isgeneric=True)
+    genericv.save()
+
+dispatcher.connect(update_render, signal=signals.pre_save, sender=Symbol)
+dispatcher.connect(update_generic_variable, signal=signals.post_save, 
+    sender=Symbol)
+
+class Variable(models.Model):
+    name = models.CharField(_("Name"), maxlength=256)
+    latex = models.TextField(_("Raw LaTeX"), unique=True)
+    unicode = models.TextField(_("Unicode Representation"), blank=True)
+    description = models.TextField(_("Description"), blank=True)
+    renderdir = "variablerenders/"
+    render = models.ImageField(_("Rendered Image"), 
+        upload_to=renderdir, editable=False)
+    reference = models.URLField(_("Reference URL"), blank=True)
+    symbol = models.ForeignKey(Symbol, verbose_name=_("Symbol"))
+    isgeneric = models.BooleanField(_("Is Generic?"), default=False)
+
+    class Meta:
+        get_latest_by = 'name'
+    class Admin:
+        ordering = ['name']
+
+    def __str__(self):
+        return self.name
+    def get_absolute_url(self):
+        return "/variable/%s/" % self.id
+    def get_admin_url(self):
+        return "/admin/variables/%s/" % self.id
+    def save(self):
+        super(Variable, self).save()
+        self.render = self.renderdir + "%s.png" % self.id
+        super(Variable, self).save()
+
+dispatcher.connect(update_render, signal=signals.pre_save, sender=Variable)
+
+class Equation(models.Model):
+    name = models.CharField(_("Name"), maxlength=256)
+    latex = models.TextField(_("Raw LaTeX"), unique=True)
+    unicode = models.TextField(_("Unicode Representation"), blank=True)
+    description = models.TextField(_("Description"), blank=True)
+    created = models.DateField(_("Created"), auto_now_add=True)
+    updated = models.DateField(_("Last Updated"), auto_now_add=True)
+    owner = models.ForeignKey(auth.User, verbose_name=_("Owner"))
+    variables = models.ManyToManyField(Variable, verbose_name="Variables",
+        editable=True)
+    renderdir = "equationrenders/"
+    render = models.ImageField(_("Rendered Image"), 
+        upload_to=renderdir, editable=False)
+    reference = models.URLField(_("Reference URL"), blank=True)
+
+    class Meta:
+        get_latest_by = 'created'
+    class Admin:
+        ordering = ['created']
+
+    def __str__(self):
+        return self.name
+    def get_absolute_url(self):
+        return "/equation/%s/" % self.id
+    def get_admin_url(self):
+        return "/admin/equations/%s/" % self.id
+    def update_variables(self):
+        """Updates the variables field with all Variable objects found
+           in the LaTeX representation."""
+        pass # TODO: write
+    def save(self):
+        self.update_variables()
+        super(Equation, self).save()
+        self.render = self.renderdir + "%s.png" % self.id
+        super(Equation, self).save()
+
+
+dispatcher.connect(update_render, signal=signals.post_save, sender=Equation)
diff --git a/equations/signals.py b/equations/signals.py
new file mode 100644
index 0000000..0fecc34
--- /dev/null
+++ b/equations/signals.py
@@ -0,0 +1,65 @@
+from django.conf import settings
+
+def update_render(sender, instance, signal, *args, **kwargs):
+    """Renders an object's .png representation using LaTeX and puts it 
+       in the right directory. Requires latex, dvipng, etc"""
+    import os, shutil, tempfile, subprocess
+    def call_command_in_dir(app, args, targetdir):
+        cwd = os.getcwd()
+        try:
+            os.chdir(targetdir)
+            p = subprocess.Popen(app + ' ' + ' '.join(args), shell=True)
+            sts = os.waitpid(p.pid, 0)
+            # FIXME -- should we raise an exception of status is non-zero?
+        finally:
+            # Restore working directory
+            os.chdir(cwd)
+
+    rawlatex = instance.latex    
+    dstdir = settings.MEDIA_ROOT + instance.renderdir
+    dstfile = "%s.png" % instance.id
+    dst = "%s" % instance.id
+
+    prologue = ""
+    latex_template = r'''
+    \documentclass[12pt]{article}
+    \pagestyle{empty}
+    %(prologue)s
+    \begin{document}
+    $$%(raw)s$$
+    \end{document}
+    '''
+    max_pages = 1
+    MAX_RUN_TIME = 5 # seconds
+    latex = "latex"
+    dvipng = "dvipng"
+    latex_args = ("--interaction=nonstopmode", "%s.tex")
+    dvipng_args = ("-q", "-bgTransparent", "-Ttight", "--noghostscript", 
+        "-l%s" % max_pages, "%s.dvi")
+    tex = latex_template % { 'raw': rawlatex, 'prologue': prologue }
+
+    tmpdir = tempfile.mkdtemp()
+    try:
+        data = open("%s/%s.tex" % (tmpdir, dst), "w")
+        data.write(tex)
+        data.close()
+        args = list(latex_args)
+        args[-1] = args[-1] % dst
+        res = call_command_in_dir(latex, args, tmpdir)
+        if not res is None:
+            # FIXME need to return some sort of error
+            return []
+        args = list(dvipng_args)
+        args[-1] = args[-1] % dst
+        res = call_command_in_dir(dvipng, args, tmpdir)
+        if not res is None:
+            # FIXME need to return some sort of error
+            return []
+
+        if os.access("%s/%s1.png" % (tmpdir, dst), os.R_OK):
+            shutil.copyfile("%s/%s1.png" % (tmpdir, dst),
+                dstdir + dstfile)
+    finally:
+        # FIXME do some tidy up here
+        instance.render = instance.renderdir + dstfile
+    shutil.rmtree(tmpdir)
diff --git a/equations/templates/equations/equation_detail.html b/equations/templates/equations/equation_detail.html
new file mode 100644
index 0000000..b4c3911
--- /dev/null
+++ b/equations/templates/equations/equation_detail.html
@@ -0,0 +1,27 @@
+{% extends "base.html" %}
+
+{% block title %}{{ object.name }}{% endblock %}
+
+{% block content %}
+<div style="width: 100px; text-align:center;">
+<img src="{{ object.get_render_url }}" style="border: none;" /></div>
+<table width="100%">
+{% if object.description %}
+  <tr><td><b>Description:</b></td><td>{{ object.description }}</td></tr>
+{% endif %}
+{% if object.variables %}
+  <tr><td><b>Variables:</b></td><td>
+    {% for variable in object.variables %}
+    <a href="{{ variable.get_absolute_url }}">{{ variable.name }}</a><br />
+    {% endfor %}
+{% endif %}
+  <tr><td><b>Raw LaTeX:</b></td><td>{{ object.latex }}</td></tr>
+{% if object.unicode %}
+  <tr><td><b>Unicode:</b></td><td>{{ object.unicode }}</td></tr>
+{% endif %}
+  <tr><td></td><td><br />
+    This equation was created on <i>{{ object.created }}</i>; 
+    it was last updated on <i>{{ object.updated }}</i>. It's owner is
+    <i>{{ object.owner }}</i>.</td></tr>
+</table>
+{% endblock %}
diff --git a/equations/templates/equations/equation_list.html b/equations/templates/equations/equation_list.html
new file mode 100644
index 0000000..c7a9632
--- /dev/null
+++ b/equations/templates/equations/equation_list.html
@@ -0,0 +1,24 @@
+{% extends "base.html" %}
+
+{% block title %}Check out all these equations!{% endblock %}
+
+{% block content %}
+{% if object_list %}
+<table width="!00%">
+  {% for item in object_list %}
+    <tr style="height:50px;"><td style="width:45%;">
+    <a href="{{ item.get_absolute_url }}" class="imglink">
+    <img style="border: none;" src="{{ item.get_render_url }}" /></a>
+    </td><td style="width: 55%"><a href="{{ item.get_absolute_url }}">
+    {{ item.name }}</a></td></tr>
+  {% endfor %}
+</table>
+{% if not is_paginated %}<br />{% if not has_previous %}
+<b><a href="./?page={{ previous }}" style="float:left;">&lt;PREV</a></b>
+{% endif %}{% if has_next %}
+<b><a href="./?page={{ next }}" style="float:right;">NEXT&gt;</a></b>
+{% endif %}{% endif %}
+{% else %}
+Fuck, where are they?
+{% endif %}
+{% endblock %}
diff --git a/equations/views.py b/equations/views.py
index 60f00ef..8e2f6fa 100644
--- a/equations/views.py
+++ b/equations/views.py
@@ -1 +1,30 @@
-# Create your views here.
+from django.core import serializers
+from models import Equation, Variable, Symbol
+from django.http import HttpResponse
+
+def all_vars(request):
+    data = serializers.serialize("json", Variable.objects.all())
+    return HttpResponse(data, mimetype="text/javascript")
+
+def all_symbs(request):
+    data = serializers.serialize("json", Symbol.objects.all())
+    return HttpResponse(data, mimetype="text/javascript")
+
+def equs_by_vars(request, whichvars):
+    vars = whichvars.split(',')
+    if len(vars) < 1:
+        return HttpResponse('[]', mimetype="text/javascript")
+    #if vars[-1] == '/':
+    #    vars = vars[:-1]
+    returnables = Equation.objects.filter(variables=vars[0])
+    if len(vars) > 1:
+        for r in returnables:
+            for i in vars[1:]:
+                if not i in r.variables:
+                    returnables = returnables.exclude(id=r.id)
+                    if len(returnables) < 1:
+                        break
+    
+    data = serializers.serialize("json", returnables)
+    return HttpResponse(data, mimetype="text/javascript")
+