Add jquery.dirty to warn user about unsaved changes

.gitignore

@@ -13,6 +13,7 @@
 
 # from test projects:
 **/static/*
+!src/inventory/static/*
 **/media/*
 *.sqlite3
 

src/inventory/static/inventory.js

@@ -0,0 +1,16 @@
+(function ($) {
+    'use strict';
+    $(function () {
+        const form_object = $(form_selector);
+        form_object.dirty({
+            preventLeaving: true,
+            onDirty: function () {
+                console.log('form is dirty');
+                var dirty_fields = form_object.dirty("showDirtyFields");
+                dirty_fields.each(function (index, element) {
+                    console.log(index + ' - ' + element.value);
+                });
+            },
+        });
+    });
+})(django.jQuery);

src/inventory/static/jquery.dirty.js

@@ -0,0 +1,308 @@
+/*
+ * Dirty 
+ * jquery plugin to detect when a form is modified
+ * (c) 2016 Simon Taite - https://github.com/simon-reynolds/jquery.dirty
+ * originally based on jquery.dirrty by Ruben Torres - https://github.com/rubentd/dirrty
+ * Released under the MIT license
+ */
+
+(function($) {
+
+    //Save dirty instances
+    var singleDs = [];
+    var dirty = "dirty";
+    var clean = "clean";
+    var dataInitialValue = "dirtyInitialValue";
+    var dataIsDirty = "isDirty";
+
+    var getSingleton = function(id) {
+        var result;
+        singleDs.forEach(function(e) {
+            if (e.id === id) {
+                result = e;
+            }
+        });
+        return result;
+    };
+
+    var setSubmitEvents = function(d) {
+        d.form.on("submit", function() {
+            d.submitting = true;
+        });
+
+        if (d.options.preventLeaving) {
+            $(window).on("beforeunload", function(event) {
+                if (d.isDirty && !d.submitting) {
+                    event.preventDefault();
+                    return d.options.leavingMessage;
+                }
+            });
+        }
+    };
+
+    var setNamespacedEvents = function(d) {
+
+        d.form.find("input, select, textarea").on("change.dirty click.dirty keyup.dirty keydown.dirty blur.dirty", function(e) {
+            d.checkValues(e);
+        });
+
+        d.form.on("dirty", function() {
+            d.options.onDirty();
+        });
+
+        d.form.on("clean", function() {
+            d.options.onClean();
+        });
+    };
+
+    var clearNamespacedEvents = function(d) {
+        d.form.find("input, select, textarea").off("change.dirty click.dirty keyup.dirty keydown.dirty blur.dirty");
+
+        d.form.off("dirty");
+
+        d.form.off("clean");
+    };
+
+    var Dirty = function(form, options) {
+        this.form = form;
+        this.isDirty = false;
+        this.options = options;
+        this.history = [clean, clean]; //Keep track of last statuses
+        this.id = $(form).attr("id");
+        singleDs.push(this);
+    };
+
+    Dirty.prototype = {
+        init: function() {
+            this.saveInitialValues();
+            this.setEvents();
+        },
+
+        isRadioOrCheckbox: function(el){
+            return $(el).is(":radio, :checkbox");
+        },
+
+        isFileInput: function(el){
+            return $(el).is(":file")
+        },
+
+        saveInitialValues: function() {
+            var d = this;
+            this.form.find("input, select, textarea").each(function(_, e) {
+
+                var isRadioOrCheckbox = d.isRadioOrCheckbox(e);
+                var isFile = d.isFileInput(e);
+
+                if (isRadioOrCheckbox) {
+                    var isChecked = $(e).is(":checked") ? "checked" : "unchecked";
+                    $(e).data(dataInitialValue, isChecked);
+                } else if(isFile){
+                    $(e).data(dataInitialValue, JSON.stringify(e.files))
+                } else {
+                    $(e).data(dataInitialValue, $(e).val() || '');
+                }
+            });
+        },
+
+        refreshEvents: function () {
+            var d = this;
+            clearNamespacedEvents(d);
+            setNamespacedEvents(d);
+        },
+
+        showDirtyFields: function() {
+            var d = this;
+
+            return d.form.find("input, select, textarea").filter(function(_, e){
+                return $(e).data("isDirty");
+            });
+        },
+
+        setEvents: function() {
+            var d = this;
+
+            setSubmitEvents(d);
+            setNamespacedEvents(d);
+        },
+
+        isFieldDirty: function($field) {
+            var initialValue = $field.data(dataInitialValue);
+             // Explicitly check for null/undefined here as value may be `false`, so ($field.data(dataInitialValue) || '') would not work
+            if (initialValue == null) { initialValue = ''; }
+            var currentValue = $field.val();
+            if (currentValue == null) { currentValue = ''; }
+
+            // Boolean values can be encoded as "true/false" or "True/False" depending on underlying frameworks so we need a case insensitive comparison
+            var boolRegex = /^(true|false)$/i;
+            var isBoolValue = boolRegex.test(initialValue) && boolRegex.test(currentValue);
+            if (isBoolValue) {
+                var regex = new RegExp("^" + initialValue + "$", "i");
+                return !regex.test(currentValue);
+            }
+
+            return currentValue !== initialValue;
+        },
+
+        isFileInputDirty: function($field) {
+            var initialValue = $field.data(dataInitialValue);
+
+            var plainField = $field[0];
+            var currentValue = JSON.stringify(plainField.files);
+
+            return currentValue !== initialValue;
+        },
+
+        isCheckboxDirty: function($field) {
+            var initialValue = $field.data(dataInitialValue);
+            var currentValue = $field.is(":checked") ? "checked" : "unchecked";
+
+            return initialValue !== currentValue;
+        },
+
+        checkValues: function(e) {
+            var d = this;
+            var formIsDirty = false;
+
+            this.form.find("input, select, textarea").each(function(_, el) {
+                var isRadioOrCheckbox = d.isRadioOrCheckbox(el);
+                var isFile = d.isFileInput(el);
+                var $el = $(el);
+
+                var thisIsDirty;
+                if (isRadioOrCheckbox) {
+                    thisIsDirty = d.isCheckboxDirty($el);
+                } else if (isFile) {
+                    thisIsDirty = d.isFileInputDirty($el);
+                } else {
+                    thisIsDirty = d.isFieldDirty($el);
+                }
+
+                $el.data(dataIsDirty, thisIsDirty);
+
+                formIsDirty |= thisIsDirty;                
+            });
+
+            if (formIsDirty) {
+                d.setDirty();
+            } else {
+                d.setClean();
+            }
+        },
+
+        setDirty: function() {
+            this.isDirty = true;
+            this.history[0] = this.history[1];
+            this.history[1] = dirty;
+
+            if (this.options.fireEventsOnEachChange || this.wasJustClean()) {
+                this.form.trigger("dirty");
+            }
+        },
+
+        setClean: function() {
+            this.isDirty = false;
+            this.history[0] = this.history[1];
+            this.history[1] = clean;
+
+            if (this.options.fireEventsOnEachChange || this.wasJustDirty()) {
+                this.form.trigger("clean");
+            }
+        },
+
+        //Lets me know if the previous status of the form was dirty
+        wasJustDirty: function() {
+            return (this.history[0] === dirty);
+        },
+
+        //Lets me know if the previous status of the form was clean
+        wasJustClean: function() {
+            return (this.history[0] === clean);
+        },
+
+        setAsClean: function(){
+            this.saveInitialValues();
+            this.setClean();
+        },
+
+        setAsDirty: function(){
+            this.saveInitialValues();
+            this.setDirty();
+        },
+
+        resetForm: function(){
+            var d = this;
+            this.form.find("input, select, textarea").each(function(_, e) {
+
+                var $e = $(e);
+                var isRadioOrCheckbox = d.isRadioOrCheckbox(e);
+                var isFile = d.isFileInput(e);
+
+                if (isRadioOrCheckbox) {
+                    var initialCheckedState = $e.data(dataInitialValue);
+                    var isChecked = initialCheckedState === "checked";
+
+                    $e.prop("checked", isChecked);
+                } if(isFile) {
+                    e.value = "";
+                    $(e).data(dataInitialValue, JSON.stringify(e.files))
+
+                } else {
+                    var value = $e.data(dataInitialValue);
+                    $e.val(value);
+                }
+            });
+
+            this.checkValues();
+        }
+    };
+
+    $.fn.dirty = function(options) {
+
+        if (typeof options === "string" && /^(isDirty|isClean|refreshEvents|resetForm|setAsClean|setAsDirty|showDirtyFields)$/i.test(options)) {
+            //Check if we have an instance of dirty for this form
+            // TODO: check if this is DOM or jQuery object
+            var d = getSingleton($(this).attr("id"));
+
+            if (!d) {
+                d = new Dirty($(this), options);
+                d.init();
+            }
+            var optionsLowerCase = options.toLowerCase();
+
+            switch (optionsLowerCase) {
+            case "isclean":
+                return !d.isDirty;
+            case "isdirty":
+                return d.isDirty;
+            case "refreshevents":
+                d.refreshEvents();
+            case "resetform":
+                d.resetForm();
+            case "setasclean":
+                return d.setAsClean();
+            case "setasdirty":
+                return d.setAsDirty();
+            case "showdirtyfields":
+                return d.showDirtyFields();            
+            }
+
+        } else if (typeof options === "object" || !options) {
+
+            return this.each(function(_, e) {
+                options = $.extend({}, $.fn.dirty.defaults, options);
+                var dirty = new Dirty($(e), options);
+                dirty.init();
+            });
+
+        }
+    };
+
+    $.fn.dirty.defaults = {
+        preventLeaving: false,
+        leavingMessage: "There are unsaved changes on this page which will be discarded if you continue.",
+        onDirty: $.noop, //This function is fired when the form gets dirty
+        onClean: $.noop, //This funciton is fired when the form gets clean again
+        fireEventsOnEachChange: false, // Fire onDirty/onClean on each modification of the form
+    };
+
+})(jQuery);

src/inventory_project/templates/admin/change_form.html

@@ -0,0 +1,10 @@
+{% extends "admin/change_form.html" %}
+{% load static %}
+
+{% block extrahead %}{{ block.super }}
+<script src="{% static "jquery.dirty.js" %}"></script>
+<script src="{% static "inventory.js" %}"></script>
+<script>
+const form_selector="#{{ opts.model_name }}_form";
+</script>
+{% endblock %}

src/inventory_project/tests/test_admin_item_normal_user_create_minimal_item_1.snapshot.html

@@ -71,6 +71,13 @@
    </script>
    <script src="/static/adminsortable2/js/inline-tabular.js">
    </script>
+   <script src="/static/jquery.dirty.js">
+   </script>
+   <script src="/static/inventory.js">
+   </script>
+   <script>
+    const form_selector="#itemmodel_form";
+   </script>
    <meta content="user-scalable=no, width=device-width, initial-scale=1.0, maximum-scale=1.0" name="viewport"/>
    <link href="/static/admin/css/responsive.css" rel="stylesheet" type="text/css"/>
    <meta content="NONE,NOARCHIVE" name="robots"/>

src/inventory_project/tests/test_admin_item_normal_user_create_minimal_item_2.snapshot.html

@@ -71,6 +71,13 @@
    </script>
    <script src="/static/adminsortable2/js/inline-tabular.js">
    </script>
+   <script src="/static/jquery.dirty.js">
+   </script>
+   <script src="/static/inventory.js">
+   </script>
+   <script>
+    const form_selector="#itemmodel_form";
+   </script>
    <meta content="user-scalable=no, width=device-width, initial-scale=1.0, maximum-scale=1.0" name="viewport"/>
    <link href="/static/admin/css/responsive.css" rel="stylesheet" type="text/css"/>
    <meta content="NONE,NOARCHIVE" name="robots"/>

src/inventory_project/tests/test_admin_memo_normal_user_create_minimal_item_1.snapshot.html

@@ -67,6 +67,13 @@
    </script>
    <script src="/static/adminsortable2/js/inline-tabular.js">
    </script>
+   <script src="/static/jquery.dirty.js">
+   </script>
+   <script src="/static/inventory.js">
+   </script>
+   <script>
+    const form_selector="#memomodel_form";
+   </script>
    <meta content="user-scalable=no, width=device-width, initial-scale=1.0, maximum-scale=1.0" name="viewport"/>
    <link href="/static/admin/css/responsive.css" rel="stylesheet" type="text/css"/>
    <meta content="NONE,NOARCHIVE" name="robots"/>