URL generatiion logic, moved D7 branch

diff --git a/recipe.js b/recipe.js
new file mode 100644 (file)
index 0000000..5f380e9
--- /dev/null
+++ b/recipe.js
@@ -0,0 +1,119 @@
+
+function choose_url (data, proxyPattern) {
+    //first try to prepare local_url from recipe
+    var local_url = data["md-url_recipe"] !== undefined
+        ? prepare_url(data["md-url_recipe"][0], data) : null;
+
+    var use_url_proxy = data["md-use_url_proxy"] !== undefined
+        ? data["md-use_url_proxy"] : "0";
+
+    //use the proxyPattern
+    if (proxyPattern && use_url_proxy == "1") {        
+        if (local_url) {
+            data["md-local-url"] = [];
+            data["md-local-url"].push(local_url);
+        }
+        var ref_local_url = prepare_url(proxyPattern, data);
+        if (ref_local_url) return ref_local_url;
+    }
+
+    // proxyPattern failed, go for local
+    if (local_url)
+        return local_url;
+
+    //local failed, go for resource
+    return data["md-electronic-url"] !== undefined
+        ? data["md-electronic-url"][0] : null;
+}
+
+var XRef = function (url, text) {  
+  this.url = url;
+  this.text = text;  
+};
+
+function has_recipe (data) {
+  var has = false;
+  if (data["md-url_recipe"] !== undefined) {
+     var recipe = data["md-url_recipe"][0];
+     if (typeof recipe == "string" && recipe.length>0) {
+       has = true;
+     }
+  }
+  return has;
+}
+
+function getUrlFromRecipe (data) {
+  if (has_recipe(data)) {
+    return prepare_url(data["md-url_recipe"][0],data);
+  } else {
+    return null;
+  }  
+}
+
+function getElectronicUrls (data) {
+  var urls = [];
+  if (data["md-electronic-url"] !== undefined) {
+    for (var i=0; i<data["md-electronic-url"].length; i++) {
+      var linkUrl = data["md-electronic-url"][i];
+      var linkText = data["md-electronic-text"][i];
+      var ref = new XRef(linkUrl, (linkText.length==0 ? "Web Link" : linkText));
+      urls.push(ref);
+    }
+  }
+  return urls;
+}
+
+
+// Prepares urls from recipes with expressions in the form:
+// ${variable-name[pattern/replacement/mode]}, [regex] is optional
+// eg. http://sever.com?title=${md-title[\s+//]} will strip all whitespaces 
+function prepare_url(url_recipe, meta_data) {
+    if (typeof url_recipe != "string" || url_recipe.length == 0)
+        return null;
+    if (typeof meta_data != "object")
+        return null;
+    try {
+        return url_recipe.replace(/\${[^}]*}/g, function (match) { 
+          return get_var_value(match, meta_data);
+        });
+    } catch (e) {
+        return "Malformed URL recipe: " + e.message;
+    }
+}
+
+function get_var_value (expr_in, meta_data) {
+    //strip ${ and }
+    var expr = expr_in.substring(2, expr_in.length-1)
+    if (expr == "") return "";
+    //extract name
+    var var_name = expr.match(/^[^\[]+/)[0];
+    if (typeof meta_data[var_name] == "undefined") return "";
+    else var var_value = meta_data[var_name][0];
+    if (var_name.length < expr.length) { //possibly a regex
+       var_value = exec_sregex(
+          expr.substring(var_name.length+1, expr.length-1),
+          var_value);
+    }
+    return var_value;
+}
+
+// exec perl-like substitution regexes in the form: pattern/replacement/mode
+function exec_sregex (regex_str, input_str) {   
+    var regex_parts = ["", "", ""];
+    var i = 0;
+    for (var j=0; j<regex_str.length && i<3; j++) {
+        if (j>0 && regex_str.charAt(j) == '/' && regex_str.charAt(j-1) != '\\')
+            i++;
+        else
+            regex_parts[i] += regex_str.charAt(j);
+    }
+    var regex_obj = new RegExp(regex_parts[0], regex_parts[2]);
+    return input_str.replace(regex_obj, regex_parts[1]);    
+}
+
+function test_url_recipe() {
+  var url_recipe = "http://www.indexdata.com/?title=${md-title[\\s+/+/g]}&author=${md-author}";
+  var meta_data = { "md-title" : ["Art of Computer Programming"], "md-author" : ["Knuth"]}
+  var final_url = prepare_url(url_recipe, meta_data);
+  alert(final_url);
+}
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