DEV: Make discourse-common an Ember addon. (#9578)

This is to help with the migration to Ember CLI. In the current running
version of Discourse everything should be the same as before, just with
a few extra files that are not used. However, using Ember CLI this can
be installed as an Ember addon.

Co-Authored-By: Jarek Radosz <jradosz@gmail.com>

app/assets/javascripts/discourse-common/addon/lib/raw-handlebars.js

@@ -0,0 +1,131 @@
+// This is a mechanism for quickly rendering templates which is Ember aware
+// templates are highly compatible with Ember so you don't need to worry about calling "get"
+// and discourseComputed properties function, additionally it uses stringParams like Ember does
+
+const RawHandlebars = Handlebars.create();
+
+function buildPath(blk, args) {
+  var result = {
+    type: "PathExpression",
+    data: false,
+    depth: blk.path.depth,
+    loc: blk.path.loc
+  };
+
+  // Server side precompile doesn't have jquery.extend
+  Object.keys(args).forEach(function(a) {
+    result[a] = args[a];
+  });
+
+  return result;
+}
+
+function replaceGet(ast) {
+  var visitor = new Handlebars.Visitor();
+  visitor.mutating = true;
+
+  visitor.MustacheStatement = function(mustache) {
+    if (!(mustache.params.length || mustache.hash)) {
+      mustache.params[0] = mustache.path;
+      mustache.path = buildPath(mustache, {
+        parts: ["get"],
+        original: "get",
+        strict: true,
+        falsy: true
+      });
+    }
+    return Handlebars.Visitor.prototype.MustacheStatement.call(this, mustache);
+  };
+
+  // rewrite `each x as |y|` as each y in x`
+  // This allows us to use the same syntax in all templates
+  visitor.BlockStatement = function(block) {
+    if (block.path.original === "each" && block.params.length === 1) {
+      var paramName = block.program.blockParams[0];
+      block.params = [
+        buildPath(block, { original: paramName }),
+        { type: "CommentStatement", value: "in" },
+        block.params[0]
+      ];
+      delete block.program.blockParams;
+    }
+
+    return Handlebars.Visitor.prototype.BlockStatement.call(this, block);
+  };
+
+  visitor.accept(ast);
+}
+
+if (Handlebars.Compiler) {
+  RawHandlebars.Compiler = function() {};
+  RawHandlebars.Compiler.prototype = Object.create(
+    Handlebars.Compiler.prototype
+  );
+  RawHandlebars.Compiler.prototype.compiler = RawHandlebars.Compiler;
+
+  RawHandlebars.JavaScriptCompiler = function() {};
+
+  RawHandlebars.JavaScriptCompiler.prototype = Object.create(
+    Handlebars.JavaScriptCompiler.prototype
+  );
+  RawHandlebars.JavaScriptCompiler.prototype.compiler =
+    RawHandlebars.JavaScriptCompiler;
+  RawHandlebars.JavaScriptCompiler.prototype.namespace = "RawHandlebars";
+
+  RawHandlebars.precompile = function(value, asObject) {
+    var ast = Handlebars.parse(value);
+    replaceGet(ast);
+
+    var options = {
+      knownHelpers: {
+        get: true
+      },
+      data: true,
+      stringParams: true
+    };
+
+    asObject = asObject === undefined ? true : asObject;
+
+    var environment = new RawHandlebars.Compiler().compile(ast, options);
+    return new RawHandlebars.JavaScriptCompiler().compile(
+      environment,
+      options,
+      undefined,
+      asObject
+    );
+  };
+
+  RawHandlebars.compile = function(string) {
+    var ast = Handlebars.parse(string);
+    replaceGet(ast);
+
+    // this forces us to rewrite helpers
+    var options = { data: true, stringParams: true };
+    var environment = new RawHandlebars.Compiler().compile(ast, options);
+    var templateSpec = new RawHandlebars.JavaScriptCompiler().compile(
+      environment,
+      options,
+      undefined,
+      true
+    );
+
+    var t = RawHandlebars.template(templateSpec);
+    t.isMethod = false;
+
+    return t;
+  };
+}
+
+export function template() {
+  return RawHandlebars.template.apply(this, arguments);
+}
+
+export function precompile() {
+  return RawHandlebars.precompile.apply(this, arguments);
+}
+
+export function compile() {
+  return RawHandlebars.compile.apply(this, arguments);
+}
+
+export default RawHandlebars;