Develop Reference

Vue.js: How to map a list of keys to Firebase objects?

I develop a small web-app based on Vue.js using Firebase to store and sync the data. I store items (e.g. with attributes title and subtitle) and lists with an attribute listitems, where an array of keys (those generated from Firebase) of items is stored. The structure looks like this:
Now the problem: I want to display a list and show the items from the listitems attribute and I'm doing it like this:
Compontent:
var ShowList = Vue.extend({
template: '#show-list',
firebase: {
// get all existing items from firebase
items: firebase.database().ref('items')
},
data: function () {
// get list item keys of list 'list_id' and bind it to this.list
this.$bindAsObject('list', listsRef.child(this.$route.params.list_id));
return {
list: this.list
};
}
});
Template:
<!-- show a list -->
<template id="show-list">
<ul v-if="list.items != ''">
<li v-for="key in list.items"> <!-- I would like to not being forced to -->
<template v-for="item in items"> <!-- iterate the whole list of existing items -->
<span v-if="item['.key'] == key">
{{ item.title }}
</span>
</template>
</li>
</ul>
<div v-else>No items.</div>
</template>
As you can see, I have to use two iterations where I iterate the full items list for every entry in list.items.
My question: Is there a more efficient way to map the actual objects to the list of object keys? For a huge number of item records, my approach will be very slow. Maybe I'm just too blind to see a simpler solution?
Thanks for your time!

I think you have to denormalize/duplicate some data there. I had a similar situation and this Firebase video cleared a lot of things up for me: https://youtu.be/ran_Ylug7AE?t=2m22s (Link updated to passage at 2:22. The whole serie is worth watching btw.)
My shot at it would be adding (Firebase) keys in "listitems", just like you have done in "items", with only the most crucial data there, so that you can link to a full description

Is your data read only? In which case you could move the filter logic from your template to your data module, like so (I expect I have unintended side-effects):
data: function () {
// get list item keys of list 'list_id' and bind it to this.list
this.$bindAsObject('list', listsRef.child(this.$route.params.list_id));
var items = firebase.database().ref('items')
var activeItems = this.list.items.map(function(key) {
return items[key]
})
return {
activeItems: activeItems;
};
}

How to sort JSON data in ng-repeat?

I am getting a server response and binding these data to view using ng-repeat. Now I want to sort these data by priceList and name. I am able to sort name using orderBy, but not with priceList. I want to sort the products based on priceList. Sorting with name will change the order of list while sorting by priceList will effect only the order of products of each category. It will effect the order of displayed category. Please help me resolve this.
My code:
<div ng-controller="Ctrl">
<pre>Sorting predicate = {{predicate}};</pre>
<hr/>
<table class="friend">
<tr>
<th>Name
</th>
<th><a href="" ng-click="predicate = 'priceList'>price</a></th>
</tr>
</table>
<div ng-repeat="data in _JSON[0].categories | orderBy:predicate">
<div ng-repeat="vals in data.itemTypeResults |orderBy:'partTerminologyName'" id="{{vals.partTerminologyName}}">
`<h4 style="background-color: gray">{{vals.partTerminologyName}} : Position :{{vals.position}}</h4>`<br>
<div ng-repeat="val in vals.products">
<b> Quantity:{{val[0].perCarQty}}</b><br>
<b> part:{{val[0].partNo}}</b><br>
<b>sku:{{val[0].sku}}</b><br>
<b> qtyInStock:{{val[0].qtyInStock}}</b><br>
<b> priceList:{{val[0].priceList}}</b><br>
<b>priceSave:{{val[0].priceSave}}</b><br>
<b> qtyDC:{{val[0].qtyDC}}</b><br>
<b> qtyNetwork:{{val[0].qtyNetwork}}</b><br>
<b> priceCore:{{val[0].priceCore}}</b><br>
</div>
</div>
</div>
JS:
$scope._JSON = [
{"categories":
[
{"id":14061,"name":"Drive Belts",
"itemTypeResults":[
{"partTerminologyName":"Serp. Belt",
"position":"Main Drive",
"products":{
"5060635":[
{"perCarQty":2,"partNo":"5060635",
"sku":"20060904","qtyInStock":2,"qtyNetwork":4,
"qtyDC":6,"priceList":19.15,"priceSave":3.29,
"priceCore":10.0}
],
"635K6":[
{"perCarQty":9,"partNo":"635K6",
"sku":"10062449","qtyInStock":2,"qtyNetwork":4,
"qtyDC":6,"priceList":18.15,"priceSave":3.21,"priceCore":10.0}
]
}
}
]
},
{"id":2610,"name":"Drive Belt Tensioners, Idlers, Pulleys & Components",
"itemTypeResults":[
{"partTerminologyName":"Drive Belt Tensioner Assembly",
"position":"N/A",
"products":{
"950489A":[
{"perCarQty":4,"partNo":"950489A",
"sku":"10150833","qtyInStock":2,"qtyNetwork":4,
"qtyDC":6,"priceList":18.15,"priceSave":3.21,"priceCore":10.0
}
]
}},
{"partTerminologyName":"Drive Belt Idler Pulley","position":"N/A",
"products":{
"89161":[
{"perCarQty":1,"partNo":"89161",
"sku":"99995959","qtyInStock":2,"qtyNetwork":4,
"qtyDC":6,"priceList":17.15,"priceSave":3.21,"priceCore":10.0}
],
"951373A":[
{"perCarQty":2,"partNo":"951373A","pla":"LTN",
"plaName":"Litens",
"sku":"10150926","qtyInStock":2,"qtyNetwork":4,
"qtyDC":6,"priceList":18.15,"priceSave":3.21,"priceCore":10.0}
]
}
}
]
}
]
}
];
$scope.predicate = '';
Fiddle: Fiddle

You might need to define a very good sorter function, or sort your products before they are interpreted by ng-repeat. I've created sorter function using underscore.js (or lodash).
You can checkout the demo (or the updated demo). Products are first sorted by category and then sorted by price in every category.
<!-- in html -->
<button ng-click="sortFn=sortByPrice">Sort By Price</button>
<button ng-click="sortFn=doNotSort">Do not Sort</button>
...
<div ng-repeat="val in sortFn(vals.products)">
...
// in js
$scope.sortByPrice = function(products) {
return _.sortBy(products, function(product) {
return product.length > 0 ? product[0].priceList : 0;
});
};
$scope.doNotSort = function(products) {
return products;
};
$scope.sortFn = $scope.doNotSort; // do not sort by default
BTW: You are directly calling val[0], which is very dangerous, if the product does not contain any elements, your code will break. My code won't ;-)
Update 1
The author asks me for a more pure Angular way solution.
Here is my answer: I think my solution is exactly in Angular way. Usually you can implement a filter (similar to orderBy) which wraps my sortByPrice. Why I don't do that, because you have ng-click to switch your order filter. I'd rather put control logic into a controller, not as pieces into view. This will be harder to maintain, when your project keeps growing.
Update 2
Okay, to make the +50 worthy, here is the filter version you want, (typed with my brain compiler) Please check in fiddle

You need to organize the products in other estructure. For example:
$.each($scope._JSON[0].categories , function( i , e) {
$.each(e.itemTypeResults, function(sub_i,sub_e) {
$.each(sub_e.products, function(itemTypeResults_i,product) {
console.log(product);
var aProduct = new Object();
aProduct.priceList = product[0].priceList;
aProduct.name = e.name;
$scope.products.push(aProduct);
});
} )
});
The code is not very friendly but what i do is putt all the products in one array so they can be ordered by the price. You have the products inside categories so that's why angular is ordering by the price in each category.
Fiddle:
http://jsfiddle.net/7rL8fof6/1/
Hope it helps.

Your fiddle updated: http://jsfiddle.net/k5fkocby/2/
Basically:
1. Digested the complex json object into a flat list of objects:
var productsToShow = [];
for (var i=0; i < json[0].categories.length; i++){
var category = json[0].categories[i];
for (var j=0; j<category.itemTypeResults.length;j++){
var item = category.itemTypeResults[j];
var products = item.products;
for (var productIndex in products) {
var productItems = products[productIndex];
for (var k=0; k<productItems.length;k++){
var productItem = productItems[k];
// Additions:
productItem.categoryName = category.name;
productItem.partTerminologyName = item.partTerminologyName;
productItem.position = item.position;
productsToShow.push(productItem);
}
}
}
}
Show category title only when needed by:
ng-repeat="product in (sortedProducts = (productsToShow | orderBy:predicate))"
and
ng-show="sortedProducts[$index - 1].partTerminologyName != product.partTerminologyName"

you can sort from your database and get final JSON data..
db.categories.aggregate([{$group : {category : {your condition} }, price: {$sort : { price: 1 } },}}])

Sorting alphabetically in JQuery with two groups

I've got a todo list. Each row has a star icon that you can click, exactly like gmail. The difference here is that if you click a star it should sort to the top (higher priority), but also re-sort within the starred group by ascending alpha. Unstarred items sort below, also sorted by ascending alpha. Everything is working as expected except for the alpha sorting. Below is the sort function where I'm doing that. I've verified that everything works below except the //sort the arrays by alpha bit...
Sort fail:
function sortTasks(currList) {
var starredTasks = [];
var unstarredTasks = [];
//create arrays
$('li.task').each(function(){
if ($(this).children('img.star').attr('src') == "images/star_checked.gif") {
starredTasks.push($(this));
} else {
unstarredTasks.push($(this));
}
});
//sort the arrays by alpha
starredTasks.sort( function(a,b){ ($(a).children('p.task-name').text().toUpperCase() > $(b).children('p.task-name').text().toUpperCase()) ? 1 : -1;});
unstarredTasks.sort( function(a,b){ ($(a).children('p.task-name').text().toUpperCase() > $(b).children('p.task-name').text().toUpperCase()) ? 1 : -1;});
//draw rows starred first, unstarred second
$(currList).empty();
for (i=0; i < starredTasks.length; i++) {
$(currList).append(starredTasks[i]);
}
for (i=0; i < unstarredTasks.length; i++) {
$(currList).append(unstarredTasks[i]);
}
}
This array has been populated with the task rows in the order they were originally drawn. The data renders fine, but basically stays in the same order.
Example task row:
<div id="task-container" class="container">
<form name="enter-task" method="post" action="">
<input id="new-task" name="new-task" type="text" autofocus>
</form>
<h2 id="today">today</h2>
<ul id="today-list">
<li id="457" class="task">
<img class="star" src="images/star_checked.gif">
<p class="task-name" contenteditable>buy milk</p>
<p class="task-date"> - Wednesday</p>
</li>
</ul>
<h2 id="tomorrow">tomorrow</h2>
<ul id="tomorrow-list">
</ul>
<h2 id="future">future</h2>
<ul id="future-list">
</ul>
<h2 id="whenever">whenever</h2>
<ul id="whenever-list">
</ul>
</div>
Each item in the starredTasks array is an entire task row. I'm assuming that $(a) is the same level as $(li)?
and here's the function that triggers the sort:
$('body').on('click', 'img.star', function(){
var thisList = '#' + $(this).parent('li').parent('ul').attr('id');
if ($(this).attr('src') == 'images/star_checked.gif') {
$(this).attr('src', 'images/star_unchecked.gif');
} else {
$(this).attr('src', 'images/star_checked.gif');
}
sortTasks(thisList);
});
Also, I doubt it's worth mentioning, but the data is stored in mySQL and prepopulated via php.
I wasn't sure of a way to use .sort() directly on the $('li') without splitting it into separate arrays...
Anybody see my goof?

I don't see where you're adding the sorted list back into the DOM. If you're not, then that's the problem. Sorting an array of elements doesn't update the DOM at all.
Furthermore, your sorting is very expensive. It's better to map an array of objects that have the elements paired with the actual values to sort.
Finally, you appear to be using the same ID multiple times on a page. That's just wrong. it may work with jQuery's .children(selector) filter, but it's still wrong. You need to change that.
Here I map an array of objects that contain a text property holding the text to sort and a task property that holds the element.
I changed p#task-name to p.task-name, so you should change that to class="task-name" on the elements.
Then I do the sort using .localeCompare(), which returns a numeric value.
Finally, the .forEach() loop appends the elements to the DOM.
var data = starredTasks.map(function(t) {
return { task: t,
text: $(t).children('p.task-name').text().toUpperCase()
};
}).sort(function(obj_a, obj_b) {
obj_a.text.localeCompare(obj_b.text);
}).forEach(function(obj) {
original_container.append(obj.task);
});
This assumes starredTasks is an actual Array. If it's a jQuery object, then do starredTasks.toArray().map(func....
The original_container represents a jQuery object that is the direct parent of the task elements.

How to filter through a table using ng-repeat checkboxes with Angularjs

Once upon a time this was working but somehow it's broken. I want to be able to produce checkboxes using ng-repeat to get as many checkboxes as required based on stored data and use these to filter through a table produced.
Additionally I don't want identical values for the checkboxes to be repeated.
I have made a plnkr with the code.
<div class="row">
<label data-ng-repeat="x in projects">
<input
type="checkbox"
data-ng-true-value="{{x.b}}"
data-ng-false-value=''
ng-model="quer[queryBy]" />
{{x.b}}
</label>
</div>
http://plnkr.co/edit/RBjSNweUskAtLUH3Ss6r?p=preview
So in summary.
Checkboxes to filter Ref.
Checkboxes to be unique.
Checkboxes to be made based off ng-repeat using Ref.

Okay, here's how to do it.
First, let's add a couple of lines of CSS in your to make sure all the checkboxes are visible:
<style>
.row { margin-left: 0px }
input[type=checkbox] { margin-left: 30px; }
</style>
Next, add the following lines to your controller:
app.filter('unique', function() {
return function (arr, field) {
var o = {}, i, l = arr.length, r = [];
for(i=0; i<l;i+=1) {
o[arr[i][field]] = arr[i];
}
for(i in o) {
r.push(o[i]);
}
return r;
};
})
app.controller("maincontroller",function($scope){
$scope.query = {};
$scope.quer = {};
$scope.queryBy = '$';
$scope.isCollapsed = true;
$scope.selectedRefs = [];
$scope.myFilter = function (item) {
var idx = $scope.selectedRefs.indexOf(item.b);
return idx != -1;
};
$scope.toggleSelection = function toggleSelection(id) {
var idx = $scope.selectedRefs.indexOf(id);
if (idx > -1) {
$scope.selectedRefs.splice(idx, 1);
}
else {
$scope.selectedRefs.push(id);
}
};
Phew.
For some reason, your Plunkr's version of AngularJS didn't recognise the unique attribute, so I added one to your controller.
Finally, change your html to this:
<div class="row">
<label data-ng-repeat="x in projects | unique:'b' | orderBy:'b'" >
<input
id="x.b"
type="checkbox"
ng-click="toggleSelection(x.b)"
ng-init="selectedRefs.push(x.b)"
ng-checked="selectedRefs.indexOf(x.b) > -1" />
{{x.b}}
</label>
</div>
... and your ng-repeat to this...
<tr ng-click="isCollapsed = !isCollapsed" ng-repeat-start="x in projects | filter:myFilter | orderBy:orderProp">
If you're interested in knowing how this works, add these lines:
<div style="margin:10px 10px 30px 10px">
<pre>{{ selectedRefs }} </pre>
</div>
I love this trick: you can see the exact contents of our "selectedRefs" array, and see it change as we tick/untick our checkboxes. This really helps when developing/testing our bindings!
As you can see, these changes use the new unique function to get your list of distinct values from your project array, and when the page first loads, we push all of the values into our new "selectedRefs" array.
["123","321","456","654","789","987"]
Then, as you tick/untick the checkboxes, we add/remove that item from this list.
Finally, we use that filter in the ng-repeat.
ng-repeat-start="x in projects | filter:myFilter | orderBy:orderProp"
Job done !
Update
If you wanted to start off with all checkboxes unticked, then it's a simple change. Just remove this line...
ng-init="selectedRefs.push(x.b)"
..and change the myFilter function to show all items initially..
$scope.myFilter = function (item) {
if ($scope.selectedRefs.length == 0)
return true;
var idx = $scope.selectedRefs.indexOf(item.b);
return idx != -1;
};
And to add a "Clear all" button, simply add a button to your form which calls a function in your AngularJS controller like this..
$scope.clearAll = function () {
$scope.selectedRefs = [];
};
(I haven't tested these suggestions though.)

ng-false-value directive needs a value set. Try ng-false-value='false' or ng-false-value='null' (in fact you can skip this one entirely if it has to just be a falsy value and not something concrete, like a string or certain number).
As you've pointed out in the comments, after selecting and then clearing the checkboxes, all rows are filtered out. It happens because unchecking the checkbox will set its value to false, and this does not agree with your entities' values (as you probably know, just stating it for others).
Therefore you do need to set this value to empty string in the end. That'd be the way:
$scope.$watch('quer.$', function () {
if ($scope.quer.$ === false) {
$scope.quer.$ = '';
}
});

Filter variable not updating in controller angularjs

Hi Im attempting to build functionality around the length of a filter in angularjs, and although its working as it should in the view, in the controller the variable seems to stay outdated...
When I click on the div below it filters a list and calls the filterby function. The output of the length of the newly filtered list updates in the view correctly. However in the function itself I have a log set and it is still showing the old length when I click on the div.
<div ng-repeat="filter in filters" ng-click="filterby(filter.filter_type)">{{filter.filter_type}}</div>
<ul>
<li ng-repeat="event in filtered = (events | filter:query) | orderBy:'-event_date' ">
<span >{{event.event_date}},{{event.event_name}}, {{event.event_venue}}, {{event.event_description}} </span>
</li>
</ul>
<br />Length of filtered items {{filtered.length}}
And my view....
$scope.filterby = function(filterby) {
if (filterby == 'ALL') {
$scope.query = '';
}
else {
$scope.query = filterby;
}
console.log($scope.filtered.length);
};
My filter data:
$scope.filters = [
{'filter_type' : 'ALL'},
{'filter_type' : 'Macnass'}
];
EDIT: Ok its not that it nots working at all, its just showing the previous value, as if its one click behind all the time, so its something to do with the fact that the variable in the view is updated after the list is made. but Im not sure how to go about insuring the variable in the controller is the latest value.
Plunker: http://plnkr.co/edit/u7KpqYx8gDwaaXEvGeMn?p=preview

check out the plunker
added below
$scope.filtered = $filter('filter')($scope.events, $scope.query)
in $scope.filterby function