Angular.js Dynamic Binding when posting to restful server - rest

I am somewhat confused of the way to achieve the two-way data binding when posting to my server.
I defined my resource like this:
angular.module('todoServices', ['ngResource']).
factory('Todo', function($resource){
return $resource('api/v1-0/todos/:todoId', {}, {
query: {method: 'GET', params:{todoId:''}, isArray: true},
save: {method: 'POST', isArray: true}
});
})
and I pass the Todo resource to my controller as a dependency.
Then in my controller I have a method to add a new Todo item to my list:
$scope.addTodo = function() {
var savedModel = new Todo();
savedModel.title = $scope.title;
savedModel.description = $scope.description,
//...
savedModel.$save();
$scope.todos.push(savedModel);
}
This works as far as my todo appears in the list, the call to the server works and the item is added in my database.
However, since when I push it to my list, it does not have an ID, yet. The ID is generated by an auto-increment ID in my MySQL database.
My server returns the object in JSON format, so I assume, I have to specify some sort of callback function to get the data-binding to work?
What exactly do I need to do, so my todo which has been added is updated with the correct ID once my server returns the data?

Simply assign the returned object to the savedModel object. Since calls to resources are asynchronous and return a promise, you should use the success function this way:
savedModel.$save(
function success(savedModel) {
$scope.todos.push(savedModel);
});
By the way, check the isArray property of the save method, normally should be false.

Related

Angular 2 Losing Data within Observable Subscription

In my application, I have a Web API controller which should be adding an entity of type "Source" to my DB, then returning the created Source. Source contains a list/collection of "SourceFields", which are themselves made up of a number of fields. Source also inherits from a base entity which I use for change tracking, and which contains fields like date created, date modified, etc.
Using Postman, I've tested my API and verified that it properly returns when I post a Source, and it includes all of objects that are created. However, when I use Angular 2 HTTP with RxJS Observables to post, the value which is returned has dropped all of the base entity fields, as well as the sourcefields. I use a Source class in Angular 2 to do operations, but I don't use it anywhere in the calls, so I don't think it's being typecasted or coerced? The only way I've gotten the source response to return properly (i.e. including the base entity properties) is if I set sourcefields to null in the API POST method.
This dataservice does work perfectly with simple entities. For example, I have a client entity that doesn't contain a collection like sourcefields, and it returns the base entity fields just fine.
Any ideas?
My API POST method:
// POST api/Sources
[HttpPost]
public IActionResult Post([FromBody]Source source)
{
if (source == null)
{
return BadRequest();
}
dbContext.Sources.Add(source);
dbContext.SaveChanges();
//Hack to get source to return properly
//source.SourceFields = null;
return CreatedAtRoute("GetSource", new { id = source.SourceId }, source);
}
Angular 2 Dataservice method:
public Add (action: string, itemToAdd: any): Observable<any> {
var toAdd = JSON.stringify(itemToAdd);
return this._http.post(this.actionUrl + action, toAdd, { headers: this.headers })
.map(res => res.json())
.catch((error: any) => Observable.throw(error.json().error || 'Server Error'));
}
The place I'm subscribing to the dataservice:
this.addEditSource.sourceFields = this.sourceFields;
this._dataService.Add('Sources', this.addEditSource).subscribe(source => {
this.sources.push(source)
},
error => console.log(error));
If anyone wants to see my entity models or anything I can add them.

Grails rest-api app to handle multiple params

Using Grails 3.1.3, I created a rest-api so that I am able to capture GET requests that not only query for one parameter, but multiple if needed. I don't know how to code this correctly inside the UrlMappings file. Here are the details.
Domain class:
class ProdDetail {
Integer pid
String title
String category
Integer year
}
And some of these inside the BootStrap:
new ProdDetail(pid:'101', title:'No Highway', author:'Nevil Shute', category:'fiction', year:1948).save(failOnError:true)
new ProdDetail(pid:'214', title:'In the Country of Men', author:'Hisham Matar', category:'misery', year:2007).save(failOnError:true)
Controller:
protected List<ProdDetail> listAllResources(Map params) {
println params
try {
ProdDetail.where {
if (params.category && params.maxYear) {
category == params.category && year <= params.int('maxYear')
} else if (params.category) {
category == params.category
} else if (params.maxYear) {
year <= params.int('maxYear')
} else {
pid > 0
}
}.list()
} catch (Exception e) {
[]
}
}
UrlMappings:
static mappings = {
"/prodDetails"(resources:'prodDetail')
"/prodDetails/category/$category?"(controller:'prodDetail', action:'index')
"/prodDetails/yearUnder/$maxYear?"(controller:'prodDetail', action:'index')
// the line below is not right I think, what's the correct format?
"/prodDetails/combo/$category?&$maxYear?"(controller:'prodDetail', action:'index')
}
Now, where as these two curls would work:
curl localhost:8080/prodDetails/category/misery
curl localhost:8080/prodDetails/yearUnder/2007
This one fails to go into the desired clause in the controller to detect both params:
curl localhost:8080/prodDetails/combo/?category=misery&maxYear=2007
It just detects 'category' but not the 'maxYear' which it considers as 'null'.
How can I cater for such a curl please?
It kind of depends on what you want your URLs to look like, but assuming you want your requests to look like this:
http://localhost:8080/prodDetails/combo/misery?maxYear=2007&title=common
The UrlMappings should look like
static mappings = {
"/prodDetails/combo/$category"(controller:'prodDetail', action:'index')
}
Then the params object in the controller should have both whatever's in the place of $category, in this example misery, and the other parameters after the ? as well.
If you want the parameters to be in the path you can do this:
static mappings = {
"/prodDetails/combo/$category/$title/$maxYear"(controller:'prodDetail', action:'index')
}
And the request would then be:
http://localhost:8080/prodDetails/combo/misery/common/2007
One other option would be to use a command object. So if you had:
static mappings = {
"/prodDetails/combosearch"(controller:'prodDetail', action:'comboSearch')
}
And then created an object beside the controller called ComboSearchCommand.groovy that looked like:
import grails.validation.Validateable
class ComboSearchCommand implements Validetable {
String category
String title
int maxYear
static constraints = {
category blank: false, nullable: true
title blank: false, nullable: true
maxYear blank: false, nullable: true
}
}
(Which you can do validation on just like a domain object)
And then in your controller you have the method take the command object instead of params
protected List<ProdDetail> comboSearch(ComboSearchCommand command) {
println command.category
}
Then your URL would be
http://localhost:8080/prodDetails/combosearch?category=misery&maxYear=2007&title=common
And the parameters will bind to the command object.
I've used that quite a bit, you can share validations or have your command object inherit validations from domain objects, lots of flexibility.
https://grails.github.io/grails-doc/latest/guide/single.html#commandObjects
You don't need to specify the parameters in UrlMappings if those params are not part of the URL:
No need of this:
"/prodDetails/combo/$category&?$maxYear?"(controller:'prodDetail', action:'index')
Yes you need this to match the URL to a controller/action (but remove the ?)
"/prodDetails/yearUnder/$maxYear?"(controller:'prodDetail', action:'index')
Also, you don't need Map params in listAllResources(Map params)
"params" is an injected property of controllers, the println params will work OK with: listAllResources()
What I would do is to define:
listAllResources(String category, int maxYear, ...) where ... are all the params that action can receive, most would be optional, so you will receive a null value if not included in your request.
Remember: UrlMappings are to map URLs to controller/actions, and you have the same controller/action, so I would remove all the mappings and process the optional parameters in the action just checking which are null or not.
Edit (considering comments)
Q: the method is not overloaded to handle params like that
A: methods are dynamic, this is Grails / Groovy, not Java. It will call the action method even if all the params are null. I would recommend you to go through the Grails controller documentation in detail.
Q: found that the listAllResources method was never called
A: remove the protected keyword from the action, only subclasses would be able to invoke that method. Also, you can add an UrlMapping to avoid users to invoke that URL (match the URL and return 404 Not Available or something like that)
Q: I want to handle a GET request like this localhost:8080/prodDetails/combo?category=misery&year=2016&title=commonTitle, how exactly should the i) entry in UrlMappings, and ii) the listAllResources method look like?
A:
static mappings = {
// if "compo" comes in the action portion, map that to the listAllResources method
// as I said, if all parameters comes in the query string, no further actions are needed, if you need parameters to be part of the URL path, then you need to play with the $xxxx in the URL
"/prodDetails/combo"(controller:'prodDetail', action:'listAllResources')
}
def listAllResources()
{
println params
// logic here
render "OK"
}
Check:
https://grails.github.io/grails-doc/latest/ref/Controllers/params.html
https://grails.github.io/grails-doc/latest/ref/Controllers/render.html
How does grails pass arguments to controller methods?

Modify routing in Sails to use something else than id?

I have a web app which talks to my backend node.js+sails app through a socket.
Default routes for sockets use id. As example
io.socket.get('/chatroom/5')
My app doesn't authenticate users and as result I want id's to be random, so nobody can guess it. However, id's are generated by mongoDB and aren't that random.
As result, I want to use some other field (a.e. "randomId") and update routing for this model to use this field instead of id.
What's the best way to do it?
P.S. It looks like I have to use policies, but still struggling to figure out what should I do exactly.
You aren't forced to use the default blueprint routes in your app; you can always override them with custom controller methods or turn them off entirely.
The GET /chatroom/:id method automatically routes to the find action of your ChatroomController.js file. If you don't have a custom action, the blueprint action is used. So in your case, you could define something like the following in ChatroomController.js:
find: function (req, res) {
// Get the id parameter from the route
var id = req.param('id');
// Use it to look up a different field
Chatroom.find({randomId: id}).exec(function(err, chatrooms) {
if (err) {return res.serverError(err);}
// Subscribe to these rooms (optional)
Chatroom.subscribe(req, chatrooms);
// Return the room records
return res.json(chatrooms);
});
}
If you don't like the name find or the param id, you can set your own route in config/routes.js:
"GET /chatroom/:randomid": "ChatroomController.myFindActionName"
Also, re:
Default routes for sockets use id.
those routes aren't just for sockets--they respond to regular HTTP requests as well!
I created a policy. This policy converts randomId (which is passed as :id) to real id and saves it in req.options.id (which Sails will pick up).
module.exports = function(req, res, next) {
var Model = req._sails.models[req.options.model];
var randomId = req.params.all()['id'];
Model.findOne().where({ randomId: randomId }).exec(function(err, record) {
req.options.id = record.id;
return next();
});
};
And I apply this policy to findOne and update actions of my controller:
ChatRoomController: {
findOne : 'useRandomId',
update : 'useRandomId'
}

How Can I Use a Proxy With Ember Data's RESTAdapter?

Right now, the Ember Data RESTAdapter is making this call:
GET /workshops
I want to make this call:
POST /scripts/server/api_call.php
{
"http_verb": "GET",
"endpoint": "special_namespace/workshops",
"data": {}
}
I'm doing stuff like session management, authorization, and OAuth signing in the api_call.php script, which makes the actual RESTful request and returns the result.
What are the steps to extend the RESTAdapter to do this?
I think you'd have to override the serialize and buildURL methods. You could also override the find call directly and bypass all of the unnecessary Ember-Data calls.
But in my opinion, the RESTAdapter is incredibly complicated nowadays. Given that your API is so different, I think you would be better off writing your own adapter from scratch. My custom REST adapter is about 100 lines long, and 20 of those are just $.ajax options. For instance, your find call could be as easy as:
find: function(store, type, id) {
return new Ember.RSVP.Promise(function(resolve) {
var data = {
http_verb: 'GET',
endpoint: 'special_namespace/' + type.typeKey.pluralize(),
data: {}
};
$.post('/scripts/server/api_call.php', data, function(response) {
resolve(response);
});
});
}

ASP.NET Web API REST Querystring - How does a client know available parameters and options?

When exposing querystring parameters using GET I have the following base URL:
https://school.service.com/api/students
This will return the first 25 students.
What if I want to return a list of students based on ONE of the following criteria:
* have accepted a job
* have received a job offer
* have no job offers
The three above choices are essentially an enum.
Therefore, the query request for students who have no job offers I assume would look like:
https://school.service.com/api/students?jobOfferStatus=3
However, I'm wondering if jobOfferStatus=3 is the proper way to handle this. If so, how would I publish/provide to the clients a list of available options for that jobOfferStatus query parameter? What about other possible query parameters and their valid options? We'll have many possible query parameters like this.
I'd love to see an example of how this should be done properly. What are the best practices?
There are two main options: documenting it, or making it discoverable. A lot of APIs have documentation where they list all of the resources and parameters for reference. Otherwise, the client won't know.
You could also make it discoverable in some way by including the options in a response. For conventions on this, search for HATEOAS if you haven't already. (I'm not really knowledgeable enough about HATEOAS myself to make a suggestion.)
I will mention that "3" is not a very meaningful value for jobOfferStatus, and there's no need for the client to know that number. You can make it anything you want -- jobOfferStatus=none or even jobOffer=none. Your controller can do the work of matching that value to your enumeration. Try to design your interface to be intuitive for developers (and, of course, write good documentation).
To handle multiple query parameters, you can use optional parameters in your function:
public HttpResponseMessage GetStudents(string jobOffer = "",
string other1 = "",
string other2 = "")
{
if (jobOffer == "accepted" && other2 == "whatever") {
// return a response
}
else {
// return a different response
}
}
When the client uses parameters by those names, you can tailor your response appropriately.
You have some options to do this, let's try to help:
1) Configure a generic route to asp.net web api knows how to solve another action's name different from Get to a get method, on the App_Start\WebConfigApi.cs class, try to add this:
config.Routes.MapHttpRoute("DefaultApiWithActionAndId",
"api/{controller}/{action}/{id}",
new { id = RouteParameter.Optional });
Using it, you can have diferent methods on the api controller:
// request: get
// url: api/Students/GetStudents
public HttpResponseMessage GetStudents()
{
return Request.CreateResponse(...);
}
// request: get
// url: api/Students/GetStudentsWithJobOffer
public HttpResponseMessage GetStudentsWithJobOffer()
{
return Request.CreateResponse(...);
}
// request: get
// url: api/Students/GetStudentsAcceptedJob
public HttpResponseMessage GetStudentsAcceptedJob()
{
return Request.CreateResponse(...);
}
2) Use a simple parameter on the Get method:
// request: get
// url: api/Students?jobOfferStatus=1
public HttpResponseMessage GetStudents(int jobOfferStatus)
{
// use jobOfferStatus parameter to fill some list
return Request.CreateResponse(...);
}
3) Use a simple method with a parameter named id, to get a default friendly url by asp.net mvc web api.
// request: get
// url: api/Students/1
public HttpResponseMessage GetStudents(int id)
{
// use the id parameter to fill some list
return Request.CreateResponse(...);
}