Refactorise saving code. Do not save and git change if there are no changes

1 files changed, 35 insertions, 19 deletions

diff --git a/core/views/expo.py b/core/views/expo.py
index 18d21a3..33a905a 100644
--- a/core/views/expo.py
+++ b/core/views/expo.py
@@ -325,20 +325,50 @@ def editexpopage(request, path):
             body = body.replace("\r", "")
             result = "%s<head%s>%s</head>%s<body%s>\n%s</body>%s" % (preheader, headerargs, head, postheader, bodyargs, body, postbody)
             
+            if result != html: # Check if content changed
+                try:
+                    write_and_commit(filepath, content)
+                except WriteAndCommitError as e:
+                    return render(request,'errors/generic.html', {'message': e.message})
+                
+            return HttpResponseRedirect(reverse('expopage', args=[path])) # Redirect after POST
+    else:
+        if filefound:
+            m = re.search(r"<title>(.*)</title>", head, re.DOTALL + re.IGNORECASE)
+            if m: 
+                title, = m.groups()
+            else:
+                title = ""
+            pageform = ExpoPageForm({"html": body, "title": title})
+        else:
+            body = "### File not found ###\n"    + str(filepath)
+            pageform = ExpoPageForm({"html": body, "title": "Missing"})
+    return render(request, 'editexpopage.html', {'path': path, 'form': pageform, })
+
+class WriteAndCommitError(Exception):
+
+    def __init__(self, message):
+        self.message = message
+
+    def __str__(self):
+        return f'WriteAndCommitError: {self.message}'
+
+def write_and_commit(filepath, content):
             cwd = filepath.parent
             filename = filepath.name
             git = settings.GIT
             # GIT see also core/models/cave.py writetrogglefile()
             # GIT see also core/views/uploads.py dwgupload()
+            
             try:
                 with open(os.path.normpath(filepath).encode(sysdefaultencoding), "w", encoding="utf8") as f:
                     print(f'WRITING{cwd}---{filename} ')
                     # as the wsgi process www-data, we have group write-access but are not owner, so cannot chmod.
                     # os.chmod(filepath, 0o664) # set file permissions to rw-rw-r--
-                    f.write(result)
+                    f.write(content)
             except PermissionError:
                 message = f'CANNOT  save this file.\nPERMISSIONS incorrectly set on server for this file {filename}. Ask a nerd to fix this.'
-                return render(request,'errors/generic.html', {'message': message})
+                raise WriteAndCommitError(message)
 
             try:
                 encoded_filename = filename.encode(sysdefaultencoding)
@@ -346,32 +376,18 @@ def editexpopage(request, path):
                 if cp_add.returncode != 0:
                     msgdata = 'Ask a nerd to fix this.\n\n' + cp_add.stderr + '\n\n' + cp_add.stdout  + '\n\nreturn code: ' + str(cp_add.returncode)
                     message = f'CANNOT git on server for this file {filename}. Edits saved but not added to git.\n\n' + msgdata
-                    return render(request,'errors/generic.html', {'message': message})
+                    raise WriteAndCommitError(message)
                
                 cp_commit = subprocess.run([git, "commit", "-m", f'Troggle online: Edit this page - {encoded_filename}'], cwd=cwd, capture_output=True, text=True)
                 # This produces return code = 1 if it commits OK, but when the repo still needs to be pushed to origin/expoweb
                 if cp_commit.returncode != 0 and cp_commit.stdout != 'nothing to commit, working tree clean':
                     msgdata = 'Ask a nerd to fix this.\n\n' + cp_commit.stderr + '\n\n' + cp_commit.stdout  + '\n\nreturn code: ' + str(cp_commit.returncode)
                     message = f'Error code with git on server for this file {filename}. Edits saved, added to git, but NOT committed.\n\n' + msgdata
-                    return render(request,'errors/generic.html', {'message': message})
+                    raise WriteAndCommitError(message)
 
             except subprocess.SubprocessError:
                 message = f'CANNOT git on server for this file {filename}. Subprocess error. Edits not saved.\nAsk a nerd to fix this.'
-                return render(request,'errors/generic.html', {'message': message})
- 
-            return HttpResponseRedirect(reverse('expopage', args=[path])) # Redirect after POST
-    else:
-        if filefound:
-            m = re.search(r"<title>(.*)</title>", head, re.DOTALL + re.IGNORECASE)
-            if m: 
-                title, = m.groups()
-            else:
-                title = ""
-            pageform = ExpoPageForm({"html": body, "title": title})
-        else:
-            body = "### File not found ###\n"    + str(filepath)
-            pageform = ExpoPageForm({"html": body, "title": "Missing"})
-    return render(request, 'editexpopage.html', {'path': path, 'form': pageform, })
+                raise WriteAndCommitError(message)
 
 class ExpoPageForm(forms.Form):
     '''The form used by the editexpopage function