[gitg] More robust templating

[Jesse van den Kieboom <jessevdk src gnome org>]

commit 5ebd683917222692a83455c6991415fe8457a369
Author: Jesse van den Kieboom <jessevdk gmail com>
Date:   Thu Jan 2 15:06:21 2014 +0100

    More robust templating

 libgitg/resources/diff-view-html-builder.js |   80 ++++++++++++++++++--------
 1 files changed, 55 insertions(+), 25 deletions(-)
---
diff --git a/libgitg/resources/diff-view-html-builder.js b/libgitg/resources/diff-view-html-builder.js
index 3aafdd0..0fdc620 100644
--- a/libgitg/resources/diff-view-html-builder.js
+++ b/libgitg/resources/diff-view-html-builder.js
@@ -3,6 +3,56 @@ function html_escape(s)
        return s.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
 }
 
+function Template(template, placeholders)
+{
+       var components = [template];
+
+       for (var i = 0; i < placeholders.length; i++)
+       {
+               var name = placeholders[i];
+               var varspec = '\\$\\{' + name + '\\}';
+               var r = new RegExp('<!-- ' + varspec + ' -->|' + varspec, 'g');
+
+               var newcomp = [];
+
+               for (var j = 0; j < components.length; j += 2)
+               {
+                       var parts = components[j].split(r);
+
+                       for (var k = 0; k < parts.length; k++)
+                       {
+                               newcomp.push(parts[k]);
+
+                               if (k != parts.length - 1)
+                               {
+                                       newcomp.push(name);
+                               }
+                       }
+
+                       if (j < components.length - 1)
+                       {
+                               newcomp.push(components[j + 1]);
+                       }
+               }
+
+               components = newcomp;
+       }
+
+       this.components = components;
+}
+
+Template.prototype.execute = function(replacements) {
+       var ret = '';
+
+       for (var i = 0; i < this.components.length - 1; i += 2)
+       {
+               var name = this.components[i + 1];
+               ret += this.components[i] + replacements[name];
+       }
+
+       return ret + this.components[this.components.length - 1];
+}
+
 function diff_file(file, lnstate, data)
 {
        tabrepl = '<span class="tab" style="width: ' + data.settings.tab_width + 'ex">\t</span>';
@@ -142,7 +192,6 @@ function diff_file(file, lnstate, data)
                file_classes = 'background';
        }
 
-       var template = data.file_template;
        var repls = {
                'FILE_PATH': file_path,
                'FILE_BODY': file_body,
@@ -151,25 +200,12 @@ function diff_file(file, lnstate, data)
                'FILE_CLASSES': file_classes
        };
 
-       for (var r in repls)
-       {
-               // As we are using the repl in the later 'template.replace()'
-               // as the replacement in which character '$' is special, we
-               // need to make sure each occurence of '$' character in the
-               // replacement is represented as '$$' (which stands for a
-               // literal '$'), so, we need to use '$$$$' here to get '$$'.
-               var repl = repls[r].replace(/\$/g, '$$$$');
-               template = template.replace(lnstate.replacements[r], repl);
-       }
-
-       return template;
+       return lnstate.template.execute(repls);
 }
 
 function diff_files(files, lines, maxlines, data)
 {
-       var f = '';
-
-       var repl = [
+       var placeholders = [
                'FILE_PATH',
                'FILE_BODY',
                'FILE_STATS',
@@ -177,13 +213,7 @@ function diff_files(files, lines, maxlines, data)
                'FILE_CLASSES'
        ];
 
-       var replacements = {};
-
-       for (var r in repl)
-       {
-               var varspec = '\\$\\{' + repl[r] + '\\}';
-               replacements[repl[r]] = new RegExp('<!-- ' + varspec + ' -->|' + varspec, 'g');
-       }
+       var template = new Template(data.file_template, placeholders);
 
        var lnstate = {
                lines: lines,
@@ -192,11 +222,11 @@ function diff_files(files, lines, maxlines, data)
                processed: 0,
                nexttick: 0,
                tickfreq: 0.01,
-               replacements: replacements,
+               template: template,
        };
 
        // special empty background filler
-       f += diff_file({hunks: [null]}, lnstate, data);
+       var f = diff_file({hunks: [null]}, lnstate, data);
 
        for (var i = 0; i < files.length; ++i)
        {