Reducing table depth option

.gitignore

@@ -1,2 +1,3 @@
 # don't check in installed node_modules
 node_modules/
+.idea

README.md

@@ -55,6 +55,29 @@ var html = tableify({
 console.log(html);
 ```
 
+reducing json depth
+-----
+
+You can additionally reduce JSON depth on some level by using additional tableify options:
+
+```javascript
+var html = tableify(json, {reduceAt: 3, reducer: () => {
+   // write some reducer function
+}});
+```
+
+In the example above all elements on 3rd level of depth will be reduced to the content returned from `reducer` function.
+
+You can also use default `reducer` function:
+
+```javascript
+var html = tableify(json, {reduceAt: 3});
+```
+
+This function returns:
+1. For arrays - message with array length.
+1. For object - if object has `value` property or has only one property, returns this value, otherwise returns message with amount of object properties.
+
 command line usage
 ------------------
 

index.js

@@ -10,7 +10,17 @@ function init(config) {
     var classes = config.classes === false ? false : true;
     var classPrefix = config.classPrefix || "";
 
-    return function tableify(obj, columns, parents) {
+    /**
+     * @param {object} options `reduceAt: number` reduces table at some depth
+     *                         `reducer: function(obj)` function used to reduce object
+     */
+    return function tableify(obj, options = {}, columns, parents) {
+        let {reduceAt = null, reducer = defaultReduce} = options;
+
+        // this element should be reduced
+        if (parents && parents.length === reduceAt)
+            obj = reducer(obj);
+
         var buf = [];
         var type = typeof obj;
         var cols;
@@ -30,20 +40,20 @@ function init(config) {
             if (Array.isArray(obj[0]) && obj.every(Array.isArray)) {
                 buf.push('<table>','<tbody>');
                 cols = [];
-                
+
                 // 2D array is an array of rows
                 obj.forEach(function (row, ix) {
                     cols.push(ix);
 
                     buf.push('<tr>');
-                    
+
                     row.forEach(function (val) {
-                        buf.push('<td' + getClass(val) + '>', tableify(val, cols, parents), '</td>')
+                        buf.push('<td' + getClass(val) + '>', tableify(val, options, cols, parents), '</td>')
                     });
-                    
+
                     buf.push('</tr>');
                 });
-                
+
                 buf.push('</tbody>','</table>');
             }
             else if (typeof obj[0] === 'object') {
@@ -69,7 +79,7 @@ function init(config) {
 
                 obj.forEach(function (record) {
                     buf.push('<tr>');
-                    buf.push(tableify(record, cols, parents));
+                    buf.push(tableify(record, options, cols, parents));
                     buf.push('</tr>');
                 });
 
@@ -81,7 +91,7 @@ function init(config) {
 
                 obj.forEach(function (val, ix) {
                     cols.push(ix);
-                    buf.push('<tr>', '<td' + getClass(val) + '>', tableify(val, cols, parents), '</td>', '</tr>');
+                    buf.push('<tr>', '<td' + getClass(val) + '>', tableify(val, options, cols, parents), '</td>', '</tr>');
                 });
 
                 buf.push('</tbody>','</table>');
@@ -93,18 +103,18 @@ function init(config) {
                 buf.push('<table>');
 
                 Object.keys(obj).forEach(function (key) {
-                    buf.push('<tr>', '<th' + getClass(obj[key]) + '>', key, '</th>', '<td' + getClass(obj[key]) + '>', tableify(obj[key], false, parents), '</td>', '</tr>');
+                    buf.push('<tr>', '<th' + getClass(obj[key]) + '>', key, '</th>', '<td' + getClass(obj[key]) + '>', tableify(obj[key], options, false, parents), '</td>', '</tr>');
                 });
 
                 buf.push('</table>');
             }
             else {
                 columns.forEach(function (key) {
                     if (typeof obj[key] === 'object' && !Array.isArray(obj[key])) {
-                        buf.push('<td' + getClass(obj[key]) + '>', tableify(obj[key], false, parents), '</td>');
+                        buf.push('<td' + getClass(obj[key]) + '>', tableify(obj[key], options, false, parents), '</td>');
                     }
                     else {
-                        buf.push('<td' + getClass(obj[key]) + '>', tableify(obj[key], columns, parents), '</td>');
+                        buf.push('<td' + getClass(obj[key]) + '>', tableify(obj[key], options, columns, parents), '</td>');
                     }
                 });
             }
@@ -130,15 +140,33 @@ function init(config) {
         return ' class="'
             + classPrefix
             + ((obj && obj.constructor && obj.constructor.name)
-                ? obj.constructor.name
-                : typeof obj || ''
+                    ? obj.constructor.name
+                    : typeof obj || ''
             ).toLowerCase()
             + ((obj === null)
-                ? ' null'
-                : ''
+                    ? ' null'
+                    : ''
             )
             + '"'
             ;
     }
 
+    // default reduce: array to array length message, object to object count of properties message, object having `value` property to this value
+    function defaultReduce(obj) {
+        if (Array.isArray(obj)) {
+            if (obj.length === 1)
+                return defaultReduce(obj[0]);
+            return `(${obj.length} elements)`;
+        } else if (typeof obj === "object") {
+            if (obj.hasOwnProperty("value"))
+                return defaultReduce(obj.value);
+            let keys = Object.keys(obj);
+            if (keys.length === 1)
+                return defaultReduce(obj[keys[0]]);
+            return `(${keys.length} properties)`;
+        }
+
+        return obj;
+    }
+
 }

test.js

@@ -1,8 +1,7 @@
 var tableify = require('./');
 var assert = require('assert');
-var fs = require('fs');
+const testData = require('./test-data');
 
-var html = fs.readFileSync('test.html','utf8');
 var obj = {
 	test : {
 		data : [
@@ -48,12 +47,24 @@ obj.fish[0].b = obj.fish;
 //console.log(tableify(obj));
 //console.log(html);
 
-assert.equal(tableify(obj) + '\n', html);
+assert.equal(tableify(obj) + '\n', testData.default);
 
 t = tableify.defaults({ classes : false })
 
 console.log(t(obj))
 
 t = tableify.defaults({ classPrefix : 'tblfy-' })
 
-console.log(t(obj))
+console.log(t(obj))
+
+// reducer tests
+console.log('reducer tests');
+t = tableify(obj, {reduceAt: 3});
+assert.equal(t + '\n', testData.reduce3);
+console.log(t);
+t = tableify(obj, {reduceAt: 2});
+assert.equal(t + '\n', testData.reduce2);
+console.log(t);
+t = tableify(obj, {reduceAt: 1});
+assert.equal(t + '\n', testData.reduce1);
+console.log(t);