Adds move and remove article modifier.

lib/models/summary.js

@@ -129,6 +129,27 @@ Summary.prototype.getPrevArticle = function(current) {
     return prev;
 };
 
+/**
+    Return the parent article, or parent part of an article
+
+    @param {String|Article} current
+    @return {Article|Part|Null}
+*/
+Summary.prototype.getParent = function (level) {
+    // Coerce to level
+    level = is.string(level)? level : level.getLevel();
+
+    // Get parent level
+    var parentLevel = getParentLevel(level);
+    if (!parentLevel) {
+        return null;
+    }
+
+    // Get parent of the position
+    var parentArticle = this.getByLevel(parentLevel);
+    return parentArticle || null;
+};
+
 /**
     Render summary as text
 
@@ -188,4 +209,15 @@ Summary.createFromParts = function createFromParts(file, parts) {
     });
 };
 
+/**
+    Returns parent level of a level
+
+    @param {String} level
+    @return {String}
+*/
+function getParentLevel(level) {
+    var parts = level.split('.');
+    return parts.slice(0, -1).join('.');
+}
+
 module.exports = Summary;

lib/modifiers/summary/index.js

@@ -1,6 +1,7 @@
-
 module.exports = {
     insertArticle:      require('./insertArticle'),
+    moveArticle:        require('./moveArticle'),
+    removeArticle:      require('./removeArticle'),
     unshiftArticle:     require('./unshiftArticle'),
 
     editPartTitle:      require('./editPartTitle'),

lib/modifiers/summary/insertArticle.js

@@ -3,18 +3,6 @@ var SummaryArticle = require('../../models/summaryArticle');
 var editArticle = require('./editArticle');
 var indexArticleLevels = require('./indexArticleLevels');
 
-
-/**
-    Get level of parent of an article
-
-    @param {String} level
-    @return {String}
-*/
-function getParentLevel(level) {
-    var parts = level.split('.');
-    return parts.slice(0, -1).join('.');
-}
-
 /**
     Insert an article in a summary at a specific position
 
@@ -27,21 +15,13 @@ function insertArticle(summary, level, article) {
     article = SummaryArticle(article);
     level = is.string(level)? level : level.getLevel();
 
-    var parentLevel = getParentLevel(level);
-
-    if (!parentLevel) {
-        // todo: insert new part
-        return summary;
-    }
-
-    // Get parent of the position
-    var parentArticle = summary.getByLevel(parentLevel);
-    if (!parentLevel) {
+    var parent = summary.getParent(level);
+    if (!parent) {
         return summary;
     }
 
     // Find the index to insert at
-    var articles = parentArticle.getArticles();
+    var articles = parent.getArticles();
     var index = articles.findIndex(function(art) {
         return art.getLevel() === level;
     });
@@ -53,11 +33,10 @@ function insertArticle(summary, level, article) {
     articles = articles.insert(index, article);
 
     // Reindex the level from here
-    parentArticle = parentArticle.set('articles', articles);
-    parentArticle = indexArticleLevels(parentArticle);
-
-    return editArticle(summary, parentLevel, parentArticle);
+    parent = parent.set('articles', articles);
+    parent = indexArticleLevels(parent);
 
+    return editArticle(summary, parent.getLevel(), parent);
 }
 
 module.exports = insertArticle;

lib/modifiers/summary/moveArticle.js

@@ -0,0 +1,81 @@
+var is = require('is');
+var removeArticle = require('./removeArticle');
+var insertArticle = require('./insertArticle');
+
+/**
+    Remove an article from a level, and insert it after another.
+
+    @param {Summary} summary
+    @param {String|SummaryArticle} from: level to remove
+    @param {String|SummaryArticle} to: level to insert after
+    @return {Summary}
+*/
+function moveArticle(summary, from, to) {
+    // Coerce to level
+    var fromLevel = is.string(from)? from : from.getLevel();
+    var toLevel = is.string(to)? to : to.getLevel();
+
+    var article = summary.getByLevel(fromLevel);
+
+    // Remove
+    var removed = removeArticle(summary, from);
+
+    // Adjust toLevel if removing impacted it
+    toLevel = arrayToLevel(
+        shiftLevel(levelToArray(fromLevel),
+                   levelToArray(toLevel)));
+    // Re-insert
+    return insertArticle(removed, to, article);
+}
+
+/**
+    @param {Array<Number>} removedLevel
+    @param {Array<Number>} level The level to udpate
+    @return {Array<Number>}
+ */
+function shiftLevel(removedLevel, level) {
+    if (level.length === 0) {
+        // `removedLevel` is under level, so no effect
+        return level;
+    } else if (removedLevel.length === 0) {
+        // Either `level` is a child of `removedLevel`... or they are equal
+        // This is undefined behavior.
+        return level;
+    }
+
+    var removedRoot = removedLevel[0];
+    var root = level[0];
+    var removedRest = removedLevel.unshift();
+    var rest = level.unshift();
+
+    if (removedRoot < root) {
+        // It will shift levels at this point. The rest is unchanged.
+        return Array.prototype.concat(root - 1, rest);
+    } else if (removedRoot === root) {
+        // Look deeper
+        return Array.prototype.concat(root, shiftLevel(removedRest, rest));
+    } else {
+        // No impact
+        return level;
+    }
+}
+
+/**
+    @param {String}
+    @return {Array<Number>}
+ */
+function levelToArray(l) {
+    return l.split('.').map(function (char) {
+        return parseInt(char, 10);
+    });
+}
+
+/**
+    @param {Array<Number>}
+    @return {String}
+ */
+function arrayToLevel(a) {
+    return a.join('.');
+}
+
+module.exports = moveArticle;

lib/modifiers/summary/removeArticle.js

@@ -0,0 +1,36 @@
+var is = require('is');
+var editArticle = require('./editArticle');
+var indexArticleLevels = require('./indexArticleLevels');
+
+/**
+    Remove an article from a level.
+
+    @param {Summary} summary
+    @param {String|SummaryArticle} level: level to remove
+    @return {Summary}
+*/
+function removeArticle(summary, level) {
+    // Coerce to level
+    level = is.string(level)? level : level.getLevel();
+
+    var parent = summary.getParent(summary, level);
+
+    // Find the index to remove
+    var index = articles.findIndex(function(art) {
+        return art.getLevel() === level;
+    });
+    if (!index) {
+        return summary;
+    }
+
+    // Remove from children
+    var articles = parent.getArticles().remove(index);
+    parent = parent.set('articles', articles);
+
+    // Reindex the level from here
+    parent = indexArticleLevels(parent);
+
+    return editArticle(summary, parent.getLevel(), parent);
+}
+
+module.exports = removeArticle;

lib/modifiers/summary/unshiftArticle.js

@@ -4,7 +4,7 @@ var SummaryPart = require('../../models/summaryPart');
 var indexLevels = require('./indexLevels');
 
 /**
-    Insert an article at the
+    Insert an article at the beginning of summary
 
     @param {Summary} summary
     @param {Article} article