[Yes:][1]

&gt; The &#39;isolate&#39; scope takes an object hash which defines a set of local scope properties derived from the parent scope. These local properties are useful for aliasing values for templates. Locals definition is a hash of local scope property to its source:   

&gt; `=` or `=attr` - set up bi-directional binding between a local scope
&gt; property and the parent scope property of name defined via the value
&gt; of the `attr` attribute. If no `attr` name is specified then the
&gt; attribute name is assumed to be the same as the local name. Given
&gt; `&lt;widget my-attr=&quot;parentModel&quot;&gt;` and widget definition of `scope: {
&gt; localModel:&#39;=myAttr&#39; }`, then widget scope property `localModel` will
&gt; reflect the value of `parentModel` on the parent scope. Any changes to
&gt; `parentModel` will be reflected in `localModel` and any changes in
&gt; `localModel` will reflect in `parentModel`. **If the parent scope
&gt; property doesn&#39;t exist, it will throw a
&gt; NON_ASSIGNABLE_MODEL_EXPRESSION exception. You can avoid this behavior
&gt; using `=?` or `=?attr` in order to flag the property as optional.**

It should trigger the expected error on every digest that affects the scope property:

    parentSet = parentGet.assign || function() {
    // reset the change, or we will throw this exception on every $digest
    lastValue = scope[scopeName] = parentGet(parentScope);
         throw Error(NON_ASSIGNABLE_MODEL_EXPRESSION + attrs[attrName] +
         &#39; (directive: &#39; + newScopeDirective.name + &#39;)&#39;);
    };

    //...


    if (parentValue !== scope[scopeName]) {
        // we are out of sync and need to copy
        if (parentValue !== lastValue) {
            // parent changed and it has precedence
            lastValue = scope[scopeName] = parentValue;
        } else {
            // if the parent can be assigned then do so
            parentSet(parentScope, lastValue = scope[scopeName]);
        }
    }


  [1]: https://docs.angularjs.org/api/ng/service/$compile 

I have been googling and reading through the SQLAlchemy documentation but haven&#39;t found what I am looking for.

I am looking for a function in SQLAlchemy that limits the number of results returned by a query to a certain number, for example: 5? Something like `first()` or `all()`.

SQLAlchemy query to return only n results?

I have two DataFrames with the following column names:

    frame_1:
    event_id, date, time, county_ID
    
    frame_2:
    countyid, state

I would like to get a DataFrame with the following columns by joining (left) on `county_ID = countyid`:

    joined_dataframe
    event_id, date, time, county, state

I cannot figure out how to do it if the columns on which I want to join are not the index.

Joining pandas DataFrames by Column names

Does the question mark after equals have special meaning? ie:

    scope: {foo: &#39;=?&#39;}

does the above mean &#39;do not raise error if &#39;foo&#39; cannot be resolved?

what&#39;s the meaning of &#39;=?&#39; in angularJS directive isolate scope declaration?

Does the question mark after equals have special meaning? ie:
<pre><code class="hljs language-css">scope: {foo: '=?'}
</code></pre>
does the above mean 'do not raise error if 'foo' cannot be resolved?

I am trying to work how to add a class with ngClick. I have uploaded up my code onto plunker [Click here][1]. Looking at the angular documentation i can&#39;t figure out the exact way it should be done. Below is a snippet of my code. Can someone guide me in the right direction

     &lt;div ng-show=&quot;isVisible&quot; ng-class=&quot;{&#39;selected&#39;: $index==selectedIndex}&quot; class=&quot;block&quot;&gt;&lt;/div&gt;

Controller

    var app = angular.module(&quot;MyApp&quot;, []);
	app.controller(&quot;subNavController&quot;, function ($scope){

			$scope.toggle = function (){
				$scope.isVisible = ! $scope.isVisible;
			};

			$scope.isVisible = false;
		});


  [1]: http://plnkr.co/edit/YRzOYU3gIBa1OfGOBSA0?p=preview

adding and removing classes in angularJs using ng-click

I am using Django Rest Framework and AngularJs to upload a file. My view file looks like this:

    class ProductList(APIView):
    	authentication_classes = (authentication.TokenAuthentication,)
    	def get(self,request):
    		if request.user.is_authenticated(): 
    			userCompanyId = request.user.get_profile().companyId
    			products = Product.objects.filter(company = userCompanyId)
    			serializer = ProductSerializer(products,many=True)
    			return Response(serializer.data)
    	
    	def post(self,request):
    		serializer = ProductSerializer(data=request.DATA, files=request.FILES)
    		if serializer.is_valid():
    			serializer.save()
    			return Response(data=request.DATA)

As the last line of post method should return all the data, I have several questions:

 - how to check if there is anything in `request.FILES`?
 - how to serialize file field?
 - how should I use parser?

Django Rest Framework File Upload

I&#39;m working on a webapp where users can login to see their online wine cellar.

I&#39;ve got the Django REST models setup, as well as the front-end design in Angular but I&#39;m having trouble putting the pieces together and my main issue is for user authentication.

I&#39;ve read many posts on here and various tutorials but I can&#39;t seem to find a step by step method to implement authentication:

 - What kind of auth should be used (Token, Session, Other?)
 - How is authentication managed on the server side (is it a view? a method in the UserModel or UserManager?)
 - I have a custom User model (using email as username). Can I use the generic Django login method or do I need to create my own?
 - How is the authentication process managed between the server and client side? 

From what I understand Angular makes a POST request on a url where DRF verifies that username and password match and returns a token or other auth proof.

I feel like I&#39;m close but I need a more general view of how this works to put the pieces together.

Thanks in advance




User Authentication in Django Rest Framework + Angular.js web app

I am developing a website that is supposed to be responsive so that people can access it from their phones. The site has got some secured parts that can be logged into using Google, Facebook, ...etc (OAuth).

The server backend is developed using ASP.Net Web API 2 and the front end is mainly AngularJS with some Razor.

For the authentication part, everything is working fine in all browsers including Android but the Google authentication is not working on iPhone and it gives me this error message

    Refused to display &#39;https://accounts.google.com/o/openid2/auth
    ?openid.ns=http://specs.openid.ne…tp://axschema.org/namePerson
    /last&amp;openid.ax.required=email,name,first,last&#39;
    in a frame because it set &#39;X-Frame-Options&#39; to &#39;SAMEORIGIN&#39;.

Now as far I am concerned I do not use any iframe in my HTML files.

I googled around, but no answer got me to fix the issue.



Refused to display in a frame because it set &#39;X-Frame-Options&#39; to &#39;SAMEORIGIN&#39;

I&#39;m using [angular-translate][1] for i18n in an AngularJS application.

For every application view, there is a dedicated controller. In the controllers below, I set the value to be shown as the page title.

##Code
###HTML

    &lt;h1&gt;{{ pageTitle }}&lt;/h1&gt;

###JavaScript

    .controller(&#39;FirstPageCtrl&#39;, [&#39;$scope&#39;, &#39;$filter&#39;, function ($scope, $filter) {
            $scope.pageTitle = $filter(&#39;translate&#39;)(&#39;HELLO_WORLD&#39;);
        }])

    .controller(&#39;SecondPageCtrl&#39;, [&#39;$scope&#39;, &#39;$filter&#39;, function ($scope, $filter) {
            $scope.pageTitle = &#39;Second page title&#39;;
        }])

I&#39;m loading the translation files using the [angular-translate-loader-url][2] extension.

## Problem
On the initial page load, the translation key is shown instead of the translation for that key. The translation is `Hello, World!`, but I&#39;m seeing `HELLO_WORLD`.

The second time I go to the page, all is well and the translated version is shown.

I assume the issue has to do with the fact that maybe the translation file is not yet loaded when the controller is assigning the value to `$scope.pageTitle`.

## Remark
When using `&lt;h1&gt;{{ pageTitle | translate }}&lt;/h1&gt;` and `$scope.pageTitle = &#39;HELLO_WORLD&#39;;`, the translation works perfect from the first time. The problem with this is that I don&#39;t always want to use translations (eg. for the second controller I just want to pass a raw string).

##Question
Is this a known issue / limitation? How can this be solved?


  [1]: http://angular-translate.github.io/
  [2]: https://github.com/PascalPrecht/angular-translate/wiki/Asynchronous-loading

Correct use for angular-translate in controllers

I have an angular directive which is initialized like so:

    &lt;conversation style=&quot;height:300px&quot; type=&quot;convo&quot; type-id=&quot;{{some_prop}}&quot;&gt;&lt;/conversation&gt;

I&#39;d like it to be smart enough to refresh the directive when `$scope.some_prop` changes, as that implies it should show completely different content.

I have tested it as it is and nothing happens, the linking function doesn&#39;t even get called when `$scope.some_prop` changes. Is there a way to make this happen ?

Angular Directive refresh on parameter change

This directive is trying to create an HTML element called progress bar that tracks progress as you move page to page. I&#39;m trying to develop it to be used as : 
    `&lt;progress-bar progress=&#39;1&#39; max=&#39;6&#39; error=&quot;true&quot;&gt;&lt;/progress-bar&gt;`

I&#39;m simply trying to pass the information from the ^^element in html to my directive and process the information to change the progress bar appropriately.

This is working for &quot;progress&quot; and &quot;max&quot; which take integer values, but for some reason the commented out code, which would process &quot;error&quot; (which is a string) is causing problems. I&#39;m new to angularJS so I&#39;m sorry if any of this sounds confusing or unclear... please ask if I need to elaborate/clarify. Thanks in advance!

    app.directive(&#39;progressBar&#39;, function(){
	
	var compileProgressBar = function(scope, elem, attrs) {
		var append = &#39;&lt;nav class=&quot;navbar navbar-fixed-bottom navbar-footer&quot; role=&quot;navigation&quot;&gt;\
	  					&lt;div class=&quot;container&quot;&gt;\
	  						&lt;div class=&quot;row&quot;&gt;&#39;;
		var i = 1;
		while (i &lt;= parseInt(scope.max)) {
			if (i &lt;= parseInt(scope.progress)) {
				//if (scope.error == &quot;true&quot;){
					//...
				//}
				//else {
				append += &#39;&lt;div class=&quot;col-xs-1&quot;&gt;&lt;div class=&quot;circle-filled&quot;&gt;&lt;center&gt;&#39;+i+&#39;&lt;/center&gt;&lt;/div&gt;&lt;/div&gt;&#39;
				//}
			} else {
				append += &#39;&lt;div class=&quot;col-xs-1&quot;&gt;&lt;div class=&quot;circle-hallow&quot;&gt;&lt;center&gt;&#39;+i+&#39;&lt;/center&gt;&lt;/div&gt;&lt;/div&gt;&#39;
			}
			i++;
		}
		append += &#39;&lt;/div&gt;&lt;/div&gt;&lt;/nav&gt;&#39;
		elem.append(append);
		elem.bind(&#39;click&#39;, function(){
			if (scope.progress &gt; 1) {
				history.back();
				scope.$apply();
			}
		});
	}

	return {
		restrict: &#39;AE&#39;,
		scope: {
			max: &#39;=max&#39;,
			progress: &#39;=progress&#39;
			//error: &#39;=error&#39;
		},
		link: compileProgressBar
	}
});

AngularJS Directive Passing String

I have a directive that can be used multiple times on a page. In the template of this directive, I need to use IDs for an input-Element so I can &quot;bind&quot; a Label to it like so:

    &lt;input type=&quot;checkbox&quot; id=&quot;item1&quot; /&gt;&lt;label for=&quot;item1&quot;&gt;open&lt;/label&gt;

Now the problem is, as soon as my directive is included multiple times, the ID &quot;item1&quot; is not unique anymore and the label doesn&#39;t work correctly (it should check/uncheck the checkbox when clicked).

How is this problem fixed? Is there a way to assign a &quot;namespace&quot; or &quot;prefix&quot; for the template (like asp.net does with the ctl00...-Prefix)? Or do I have to include an angular-Expression in each id-Attribute which consists of the directive-ID from the Scope + a static ID. Something like:

    &lt;input type=&quot;checkbox&quot; id=&quot;{{directiveID}} + &#39;item1&#39;&quot; /&gt;&lt;label for=&quot;{{directiveID}} + &#39;item1&#39;&quot;&gt;open&lt;/label&gt;

**Edit:**

My Directive

    module.directive(&#39;myDirective&#39;, function () {
        return {
            restrict: &#39;E&#39;,
            scope: true, 
            templateUrl: &#39;partials/_myDirective.html&#39;,
            controller: [&#39;$scope&#39;, &#39;$element&#39;, &#39;$attrs&#39;, function ($scope, $element, $attrs) {
                ...
            } //controller
        };
    }]);

My HTML

    &lt;div class=&quot;myDirective&quot;&gt;
      &lt;input type=&quot;checkbox&quot; id=&quot;item1&quot; /&gt;&lt;label for=&quot;item1&quot;&gt;open&lt;/label&gt;
    &lt;/div&gt;

Directive template unique IDs for elements in AngularJS

I know that I can get access to the click event from `ng-click` if I pass in the `$event` object like so:

    &lt;button ng-click=&quot;myFunction($event)&quot;&gt;Give me the $event&lt;/button&gt;
    
    &lt;script&gt;
      function myFunction (event) {
        typeof event !== &quot;undefined&quot; // true
      }
    &lt;/script&gt;


It&#39;s a little bit annoying having to pass `$event` explicitly every time. Is it possible to set `ng-click` to somehow pass it to the function by default?

Automatically pass $event with ng-click?

I am having issues getting my directive to render its content only after my promise has been resolved. I thought `then()` was supposed to do this but it doesn&#39;t seem to be working..

Here is my controller:

    // Generated by CoffeeScript 1.6.3
    (function() {
      var sprangularControllers;

      sprangularControllers = angular.module(&#39;sprangularControllers&#39;, [&#39;sprangularServices&#39;, &#39;ngRoute&#39;]);

      sprangularControllers.controller(&#39;productsController&#39;, [
        &#39;$scope&#39;, &#39;$route&#39;, &#39;$routeParams&#39;, &#39;Product&#39;, &#39;Taxonomy&#39;, function($scope, $route, $routeParams, Product, Taxonomy) {
          Taxonomy.taxonomies_with_meta().$promise.then(function(response) {
            return $scope.taxonomies = response.taxonomies;
          });
          return Product.find($routeParams.id).$promise.then(function(response) {
            return $scope.currentProduct = response;
          });
        }
      ]);

    }).call(this);

My directive: 

    // Generated by CoffeeScript 1.6.3
    (function() {
      var sprangularDirectives;

      sprangularDirectives = angular.module(&#39;sprangularDirectives&#39;, []);

      sprangularDirectives.directive(&#39;productDirective&#39;, function() {
        return {
          scope: {
            product: &#39;=&#39;
          },
          templateUrl: &#39;partials/product/_product.html&#39;,
          link: function(scope, el, attrs) {
            console.log(scope);
            console.log(scope.product);
            return el.text(scope.product.name);
          }
        };
      });

    }).call(this);

Scope returns okay, and when I check it in dev tools `scope.product` is not undefined however I am presuming that is because by the time I check it the promise has been resolved?

`console.log(scope.product)` however, returns undefined..



Content Type	Original Author	Original Content on Stackoverflow
Question	Nikita	View Question on Stackoverflow
Solution 1 - Angularjs	Matt Zeunert	View Answer on Stackoverflow

what's the meaning of '=?' in angularJS directive isolate scope declaration?

Angularjs Problem Overview

Angularjs Solutions

Solution 1 - Angularjs

Joining pandas DataFrames by Column names

SQLAlchemy query to return only n results?

Attributions