Creating filters in EmberJS - Concept - javascript

I need some ideas on how to create a search filter in EmberJS where the search results can persist across views. Lets say I have a list of contacts and I filtered the list. Assume this route is called Contacts/Index
Now I have a second route called Contacts/Details. The user will be directed to this route once they select a result from the contact list. Now when they click 'Back To Contacts', I want the previous filter to be still applied instead of showing all the Contacts.
I didn't write any code yet, so I can't provide a JSFiddle. All I can think of now is probably to create a global variable to keep track of the text that is used to filter and apply that when transitioning back to the Contacts/Index view but I'm not sure if it is the right way to do it.

This is just pseudo-code that doesn't really care what your filter type is, but you could apply a filter property to the ContactsIndexController:
App.ContactsIndexController = Ember.ArrayController.extend({
//...
filter: 'name=bro',
filteredContent: function () {
if(this.get('filter')){
return this.get('content').filter//...;
} else {
return this.get('content');
}
}.property('filter')
//...//
});
Whenever you change the filter, make sure to update the filter property:
this.set('filter', 'foo=bar');
Then in your handlebars template you always loop over filteredContent:
{{#each filteredContent}}
{{/each}}
When you transition back and forth between the Contacts inner routes, it should retain the filter when you return to the index.
You can also see how this pattern could be used to take this one step further and manipulate the filter from literally anywhere in the application. If you aren't in that controller's context, you can still update that property and bindings will appropriately render the computed property next time you visit.
From another controller:
this.set('controllers.contacts-index.filter', 'year=20x6')
From a route:
this.controllerFor('contacts-index').set('filter', 'year=20x6')
From a view within the index controller:
this.set('controller.filter', 'year=20x6')
I'm sure you get the idea.
This is, of course, one of several approaches you could take. I prefer this particular pattern.
Hope that helps and good luck!

Related

Ember: Getting model data in the controller

I am new to ember and I am building a DnD character sheet to learn and practice. Right now I am having a lot of trouble getting access to model data in a controller. After hours and hours of reading related posts it is just not clicking and I think I am misunderstanding what I am passing to the controller.
Basically what I am trying to do is grab data from a model so I can do calculations on them and then display the results of those calculations on the page.
Here is my transforms/router.js:
Router.map(function() {
this.route('characters', { path: '/'})
this.route('new', {path: 'new'});
this.route('view', {path: '/:character_id'});
});
So here I am trying to pull up the view page which has the URL of the character id. Next here is my route for the view page:
export default Route.extend({
character: function () {
return this.store.findRecord('character', id)
}
});
So this is finding the record of the character with the id I pass. My link looks like this and is coming from a component:
<h5 class="card-title">{{#link-to 'view' id}}{{name}}{{/link-to}}</h5>
Now I have my controller for the view page, which looks like this:
init(id){
let character = this.get('character')
}
When I try to log character, it is still undefined. When looking ember information in dev tools it seems the page is getting the information from the model after I refresh the page, but I just can't seem to be figure out how to grab that info in the controller itself to manipulate it.
I've been trying to figure this out for quite a while now, and its getting pretty frustrating. I currently have a work around where I do the calculations beforehand and just store all the calculated results in the model as well, but while I am learning I would like to understand how this works. Thanks is advance.
Edit: As pointed out in comments below I was missing let when defining character.
Your model hook seems wrong. You're using id but never define it. Probably what you want is more like this:
character(params) {
return this.store.findRecord('character', params.character_id);
}
Next your init hook makes no sense:
init(id){
let character = this.get('character')
}
First there is no id passed to the init hook. Second you're missing this._super(...arguments) which should always be called when you override init.
Last is that your controller is first created and later populated with the model. Also the model is populated as model property, not character.
So you could place this in your routes template and it will work:
This is character {{model.id}}
Or if you want to change something before you pass it to the template you should use a computed property in your controller:
foo: computed('model.id', function() {
return this.get('model.id') + ' is the id of the character';
}),
However for this code to run you need to use. The easiest way to use it is to put it into your template:
{{foo}}

Meteor react design - nested component: function call

I'm currently facing a problem with Meteor and React, where i know some partly solutions but they don't work and imo none of them is pointing in the true direction.
The situation:
All is about an fitness app: I have a structure that represents exercises for customers, while each exercise can have a defined number of sets (a set is how often a exercise should be done). Each set has some properties (all the user can manipulate within the font-end).
Now i have the following component structure with some map-functions (state properties are in {}):
Training {customers,exercises,datetime,otherinfos}
- Overview {customers,exercises}
exercises.map():
- Exercise {exercise,customers}
customers.map():
- Customer {exercise,customer}
exercise.sets.map()
Set {exercise, customer, set, valuesofset}
From a UI-perspective (react) this all works without problems.
Now the idea is to have a button "Save" within the Training component. When the button is pressed, I want to save the state of all Set-Components in a "sets" collection (if it has other values than the default placeholder ones) and at the same time save the Training-Component in a "trainings" collection. But the training should also include information about what Sets are integrated (so at least the Set._id should be in the Training-Component state at time of Saving.
Here now my ideas so far:
Create refs from Training all the way down to all Sets and then, when pressing "Save" iterate over all refs and call a "Mongo.insert" from all Sets. Here i have the problem that i cannot return the inserted _id. Of course i could call a different function in each Component from Set all the way back to Training, but imo this is an overflow.
Try to manage the state of all sets within the Training state by calling a nested function. As i have onChangeHandler on the Inputs, this would always call a method in Training and check which one of the Sets was changed and then changes it. I have tried it this way, but it led to a very bad performance.
Create a temp-ID for Training, forward it to to the Sets (using the componentWillReceiveProps method) and when in Set, insert the Set in the database with the temp-ID. Then receive all Sets with temp-ID and use it to add the Training in the database. --> imo very complicated and I don't really want to do a database call if it is not necessary.
So currently i don't know how to solve this problem. The reason i try to separate "sets" and "trainings" is given through the fact, that later on i would like to give information about the last Set right next to the new empty Set whenever one is on the database. Any tips are welcome!
EDIT:
As suggested, there is also the possibility to solve the problem with Session. So therefor i have added the following code to Set:
componentDidMount() {
Tracker.autorun(() => {
Session.set(`set_${this.state.id}`, {
...this.state
});
});
}
My idea was then to iterate over all Session-Keys from Training which start with "set_" - unfortunately there is no function to that holds all Keys.
Second idea was to to use an array as value for a Session-pair. However, it's quite a procedure to handle the update of the reactive Set component (copy array from session, check whether an element is available or not, create a new one or update the existing one).
EDIT2:
I think i got a solution with Session:
Object.getOwnPropertyNames(Session.keys)
did the trick to get all SessionKeys! Thank you for your help!
If you do not want to use Redux or pass parent bound callbacks in the child component, you can try Session to store data at app level which can be accessed(set/get) in any component
https://docs.meteor.com/api/session.html
In your case, you may set values of "Set" in Session and access it in Training. You may also need https://guide.meteor.com/react.html#using-withTracker. Using withTracker will help in doing reactive update of the database on change of any Session variable.

having trouble with dynamic segments in emberjs

This should be simple to do. I just can't pass the value of the input to the product-details view. I'm trying to create a unique template page for each item added to the list. Clicking the 'details' link should take the user to the unique page. I understand how dynamic segments works, I'm just getting stuck somewhere.
Thanks!
http://emberjs.jsbin.com/midivu/1/edit?html,js,output
In your link to helper you need to pass the parameter in...
{{#link-to 'details' name class="add-item-button"}}
Example..
If you imagine link-to as a function then in your case it would be
linkTo(route, segment, etc...)
But imagine it this way just to understand the adding parameter...
To fix your Details Route
App.DetailsRoute = Ember.Route.extend({
model: function(params) {
return userList.findBy('name', params.itemName); // assuming you want to find the details by it's name
}
});
This is because you did not create a data store. You are using a global variable as your data store, therefore, you must get it from the global.

Where does data returned by ember-data 'live'?

ya'll I have a bit of a structural/procedural question for ya.
So I have a pretty simple ember app, trying to use ember-data and I'm just not sure if I'm 'doing it right'. So the user hits my index template, I grab their location coordinates and encode a hash of it (that part works). Then on my server I have a db that stores 'tiles' named after there hash'd coords (if i hit my #/tiles/H1A2S3H4E5D route I get back properly formatted JSON).
What I would like to happen next, if to display each of the returned tiles to the user on the bottom of the first page (like in a partial maybe? if handlebars does that).
I have a DS.Model for the tiles, if I hard code the Hash'd cords into a App.find(H1A2S3H4E5D); I can see my server properly responding to the query. However, I cannot seem to be able to figure out how to access the returned JSON object, or how to display it to the user.
I did watch a few tutorial videos but they all seem to be outdated with the old router.
Mainly I would like to know:
1. Where does the information returned by App.find(); live & how to access it?
2. what is the 'correct' way to structure my templates/views to handle this?
3. how should I pass that id (the hash'd coords) to App.find? as a global variable? or is there a better way?
the biggest problem(to me) seems to be that the id I search by doesn't exist until the user hit the page tho first time. (since its dynamically generated) so I can't just grab it when the page loads.
I can post a fiddle if required, but I'm looking for more of a conceptual/instructional answer rather then some one to just write my code for me
I'm still learning a lot with Ember as well, but this is my understanding. When you follow the guides and the tutorials out there, you'll have something like this:
App.TileController = Ember.ObjectController.extend();
App.TileRoute = Ember.Route.extend({
setupController: function(controller) {
controller.set('content', App.Tile.find(MYHASH));
}
});
What it does is set the special content object to the result. So since we're declaring an object controller, and calling find with a parameter, it knows that a single result is expected. So a view & template that follow the naming convention of Tile will be loaded. And in there you can access properties on the Tile object:
<p>{{lat}}</p><p>{{lng}}</p>
I have to admit that this feels a bit mystical at times. The core to it is all in the naming convention. You need to be pretty specific in how you name all your various controllers, routes, etc. Once that's nailed down, it's a matter of binding what data you want to the controller's content.
1) Aside from the generic answer of "in memory", the .find() calls live where ever you return it to. Generally speaking, this is meant to be set on a 'content' property of a controller.
2) I more or less answered this, but generally speaking you take the name of your route, and base it off that. So for a route TileRoute, you have:
TileController = Ember.ObjectController.extend
Tile = DS.Model.extend
TileView = Ember.View.extend
tile.handlebars
I generally store all my handlebars files in a templates/ folder. If you nest them deeper, just specify the path in your view object:
App.TileView = Ember.View.extend({
templateName: "tiles/show"
});
3) This really depends on your app. Generally speaking its better for the id to be either obtained from the URL, or constructed locally in a function. Since you are encoding a hash, i imagine you're doing this in a function, and then calling find. I do something a bit similar for an Array controller.
I don't know at what point you are generating a hash, so let's say it's onload. You should be able to generate the hash just in the setupController function.
App.TileRoute = Ember.Route.extend({
generateHashBasedOnCoords: function() {
// ...
},
setupController: function(controller) {
var MYHASH = this.generateHashBasedOnCoords();
controller.set('content', App.Tile.find(MYHASH));
}
});
I hope that helps.
I believe that you can make use of the data binding in ember and basically have an array controller for tiles and set the content initially to an empty array. Then we you get back your response do a App.find() and set the content of the tiles controller with the data that is returned. This should update the view through the data binding. (Very high level response)
The data itself is stored in a store that is setup with ember data. You access it with the same method you are using the model methods App.Tile.find() ect. It checks to see if the data that is needed is in the store if so it returns the data otherwise it makes a call to the api to get the data.

Ember.js adds elements to collection "magically"

Question related somewhat to: Ember.js: retrieve random element from a collection
I've two routes: randomThing route and things route.
The former displays a... random thing from an API (GET /things/random) (there is a button to "Get another random thing"), the latter: displays all things: (GET /things).
The problem is that EVERY TIME when I click on Get another random thing and new thing is displayed and I go to recipes route this newly displayed random thing is added to the collection...
Action to get random thing performs a find("random") as suggested in related question and sets this.content to this value.
What is wrong here?
EDIT:
I'm using ember-data and my route is like this:
App.ThingsRoute = Ember.Route.extend({
model: function() {
return App.Thing.find();
}
});
The problem is that EVERY TIME when I click on Get another random thing and new thing is displayed and I go to recipes route this newly displayed random thing is added to the collection...
This is expected behavior. App.Thing.find() does not simply query the api and return results. Instead find() returns an array containing of all Things ember knows about. It includes objects returned by past calls to find(), objects created client-side via App.Thing.createRecord(), and of course individual objects queried via App.Thing.find('random'). After returning this array, find() and kicks off another API call and if that returns additional records they are pushed onto the array.
What is wrong here?
It does not sound like anything is wrong per-se. If you want to prevent random things from showing up in the ThingsRoute, you'll need to change that route's model to be a filter instead of just returning every Thing. For example:
App.ThingsRoute = Ember.Route.extend({
model: function() {
//Kick off query to fetch records from the server (async)
App.Thing.find();
//Return only non-random posts by applying a client-side filter to the posts array
return App.Thing.filter(function(hash) {
if (!hash.get('name').match(/random/)) { return true; }
});
}
});
See this jsbin for a working example
To learn more about filters I recommend reading the ember-data store-model-filter integration test

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