Template manipulation in Angular.js - angularjs

I am trying to modify an Angular template before any other directive is triggered, in particular interpolation. I am doing this through the compile option in the directive definition.
Here is my test code:
<!doctype html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.10/angular.js"></script>
<script>
angular.module('soQuestion', [])
.directive('example', function () {
return {
compile: function (tElement, tAttrs) {
if (tAttrs.foo && tAttrs.foo.match(/^keyword/)) {
tElement.attr('foo', 'prefix-' + tAttrs.foo);
console.log(tElement.attr('foo'));
}
}
};
})
.controller('controller', function($scope) {
$scope.value = 'something';
});
</script>
</head>
<body ng-app="soQuestion">
<div ng-controller="controller">
<div example foo="keyword_{{value}}"></div>
</div>
</body>
</html>
However, the final result that I get is <div foo="keyword_something"></div> instead of <div foo="prefix-keyword_something"></div>, even if the compile function was triggered properly. What is going on here?

Its a directive priority issue, and admittedly I still don't completely understand. But don't for get that {{}} is itself a directive. Its getting applied in some order with yours, and overwriting your manipulation. If its terminal and high priority, it clears up.
DEMO
angular.module('soQuestion', [])
.directive('example', function () {
return {
priority: 1000,
terminal : true,
compile: function (tElement, tAttrs) {
if (tAttrs.foo && tAttrs.foo.match(/^keyword/)) {
tElement.attr('foo', 'prefix-' + tAttrs.foo);
console.log(tElement.attr('foo'), tElement[0]);
}
return function(){};
}
};
})
.controller('controller', function($scope) {
$scope.value = 'something';
});
because this breaks the {{}} I would consider compiling the attr manually as well.

angular.module('soQuestion', [])
.directive('example', function () {
return {
compile: function (tElement, tAttrs) {
if (tAttrs.foo && tAttrs.foo.match(/^keyword/)) {
// Change the tAttrs hash instead of the element itself
tAttrs.foo = 'prefix-' + tAttrs.foo;
// Change the element too, in case no interpolation is present
tElement.attr('foo', tAttrs.foo);
console.log(tElement.attr('foo'));
}
}
};
})
Explanation: the interpolate directive does check for changes in the attribute value. However it doesn't look again on the DOM node itself but on the tAttrs hash.
Old pessimistic answer:
I don't think it's possible to achieve the desired result.
Looking at Angular's source, collectDirectives puts together the list of directives that affect a certain node. Their respective compile functions are collected and then sorted by priority. The problem is that the compile function of {{}} is then bound to keyword_{{value}} and is not affected by the example directive.

Related

AngularJS1 directive with `terminal:true` will disable rendering of expressions, why?

HTML code:
<div ng-controller="MyController">
<div>{{ hello }}</div>
<div my-terminal>{{hello}}</div>
</div>
JS code:
const app = angular.module('app', [])
app.controller('MyController', function ($scope) {
$scope.hello = 'Hello, AngularJS'
})
app.directive('myTerminal', function () {
return {
restrict: 'A',
terminal: true,
link: function () {
console.log('--- myTerminal')
}
}
})
Please notice the terminal is true.
Result:
From angularjs document, I found when terminal is true, any other directives applied on the same element with lower priority will not be executed, but I can't explain why <div my-terminal>{{hello}}</div> will not render the expression {{hello}}
A small complete demo for this question: https://github.com/freewind-demos/angularjs1-directive-terminal-issue-demo
https://github.com/angular/angular.js/blob/master/src/ng/compile.js :
function addTextInterpolateDirective(directives, text) {
var interpolateFn = $interpolate(text, true);
if (interpolateFn) {
directives.push({
priority: 0,
compile: function textInterpolateCompileFn(templateNode) {
var templateNodeParent = templateNode.parent(),
hasCompileParent = !!templateNodeParent.length;
...
So using expression {{}} results in adding directive. Guess thats why it is affected by 'terminate' property.
From the Docs:
terminal
If set to true then the current priority will be the last set of directives which will execute (any directives at the current priority will still execute as the order of execution on same priority is undefined). Note that expressions and other directives used in the directive's template will also be excluded from execution.
— AngularJS Comprehensive Directive API Reference - terminal
A better explaination of what that means comes from the Docs for ng-non-bindable which uses the terminal property:
ngNonBindable
The ngNonBindable directive tells AngularJS not to compile or bind the contents of the current DOM element, including directives on the element itself that have a lower priority than ngNonBindable. This is useful if the element contains what appears to be AngularJS directives and bindings but which should be ignored by AngularJS. This could be the case if you have a site that displays snippets of code, for instance.
— AngularJS ng-non-bindable Directive API Reference
You need to use ng-bind
<div ng-controller="MyController">
<div>{{hello}}</div>
<div my-terminal ng-bind="hello"></div>
</div>
The DEMO
const app = angular.module('app', [])
app.controller('MyController', function ($scope) {
$scope.hello = 'Hello, AngularJS'
})
app.directive('myTerminal', function () {
return {
restrict: 'A',
terminal: true,
link: function () {
console.log('--- myTerminal')
}
}
})
<script src="//unpkg.com/angular/angular.js"></script>
<body ng-app="app" ng-controller="MyController">
<div>{{ hello }}</div>
<div my-terminal ng-bind="hello"></div>
</body>

Function of isolated scope gets called multiple times

I wrote an angular code to implement Like and remove Like functionality. For this purpose I used a directive "like-directive" which takes three functions
1. upFn : code to be executed when liked
2. downFn: code to be executed when like removed
3. upvChk: function which checks whether it is liked or not. I started this with false
For some reason I cannot use a variable with ng-if. I have to use the upvChk function. But this function is getting called more than twice. It should be called only twice because I'm using ng-if twice.
Here is the codepen link http://codepen.io/puneet27/pen/jApJww/
angular.module('app',[])
.controller('MainCtrl',['$scope',MainCtrl])
.directive('likeDirective',[likeDirective]);
function MainCtrl($scope){
var mcl = this;
mcl.checkUpvoted = checkUpvoted;
mcl.upvote = upvote;
mcl.downvote = downvote;
function checkUpvoted(){
alert("function to check whether liked or not");
return mcl.upvoted;
}
function upvote(){
alert('like completed');
mcl.upvoted = true;
}
function downvote(){
alert('dislike completed');
mcl.upvoted = false;
}
}
function likeDirective(){
return {
restrict: 'E',
scope: {
upFn:'&upFn',
downFn:'&downFn',
upvChk:'&upvChk'
},
templateUrl: 'tpl.html'
}
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="app">
<div ng-controller="MainCtrl as mc">
<like-directive up-fn="mc.upvote()" down-fn="mc.downvote()" upv-chk="mc.checkUpvoted()"></like-directive>
</div>
<script type="text/ng-template" id="tpl.html">
<div><span id="upvote" ng-if="!upvChk()" ng-click="upFn()">Like</span><span id="upvoted" ng-if="upvChk()" ng-click="downFn()">Liked</span></div>
</script>
</div>

block-ui-pattern has no effect

i am trying to implement block-ui into our angular application on an element by element basis. (everything is included, referenced and injected correctly)
We have been trying to implement
block-ui-pattern
with no success.
our $http request is :-
$http.get('/user/123/GetUserAddress/').then(function (data) {
and our block-ui-pattern is :-
< div block-ui block-ui-pattern="/^user\/123\/GetUserAddress\$/">
{{address}}
</div>
This seems to match the documentation, but is failing to work. Am i missing something fundamental?
Our application exposes an isloading flag. initially set to true, and when the $http promise returns, sets this to false.. I realize that it is not in the documentation, however, Is there a way to set
< div block-ui="isloading"></div>
Post by Parash Gami pointed me in the right direction.
I actually ended up writing a custom directive that wraps block-ui
var myBlocker = angular.module('app.Angular.Directive.myBlocker ', []);
myBlocker.directive('myBlocker ', ['$compile', function ($compile) {
return {
restrict: 'A',
scope :{
blockId: '#id',
block: '=',
},
controller: ['$scope', 'blockUI', function ($scope, blockUI) {
var myBlock = blockUI.instances.get($scope.blockId);
$scope.$watch('block', function (newValue, oldValue) {
if ($scope.block === true)
{
myBlock.start()
}
else {
myBlock.stop()
}
});
}],
link: function link(scope, element, attrs) {
element.attr('block-ui', scope.blockId);
element.attr('style', 'min-height:200px;');
element.removeAttr("my-blocker");
element.removeAttr("data-my-blocker");
$compile(element)(scope);
}
};
}]);
This allows me to now simply add the directive to an element
< div id="myId" my-blocker block="loading">
Please check sample code. Just include one CSS and one JS of blockUI and add dependency blockUI, use blockUI.start() method to show loader and use blockUI.stop() method to hide loader. Following example hide loader after 2 seconds. Use it as per your requirement.
<!DOCTYPE html>
<html>
<head>
<title></title>
<link rel="stylesheet" type="text/css" href="http://angular-block-ui.nullest.com/angular-block-ui/angular-block-ui.css">
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.9/angular.min.js"></script>
<script type="text/javascript" src="http://angular-block-ui.nullest.com/angular-block-ui/angular-block-ui.js"></script>
</head>
<body ng-app="app.user">
<div ng-controller="tempController">
</div>
</body>
</html>
<script type="text/javascript">
var app = angular.module('app.user',['blockUI']);
app.controller('tempController', function(blockUI,$timeout)
{
blockUI.start();
$timeout(function()
{
blockUI.stop();
},2000)
});
</script>

How can an Angular directive compile() function access an isolated scope?

I have the following directive:
angular.module("example_module", [])
.directive("mydirective", function() {
return {
scope: { data: "#mydirective" }
compile: function(element) {
element.html('{{example}}');
return function($scope) {
$scope.example = $scope.data + "!";
};
}
};
});
and the following HTML code:
<!DOCTYPE html>
<html ng-app="example_module">
<head>
<meta charset="utf-8">
<title>Example title</title>
<script src="lib/angular/angular.min.js"></script>
<script src="js/example.js"></script>
</head>
<body>
<div mydirective="Hello world"></div>
</body>
</html>
I would expect the directive to compile to Hello world!, but it compiles to an empty string instead. scope creates an isolated scope which seems impossible to reach for {{example}}.
I would like to know how the new HTML code created by compile() can access the link function $scope.
This doesn't work because {{example}} is being evaluated against the parent scope, which makes sense, since you are essentially changing the element before compilation to:
<div>{{example}}<div>
You can verify by replacing '$scope.example =' with '$scope.$parent.example =' (for demonstration purposes only - it's not a best practice to use $parent).
What you are really trying to do is something similar to transclusion, but there are very easier ways to do it. For instance:
angular.module("example_module", [])
.directive("mydirective", function() {
return {
restrict: 'A',
scope: { data: "#mydirective" },
template: '{{example}}',
compile: function(element) {
return function($scope) {
console.log($scope.data);
$scope.example = $scope.data + "!";
console.log($scope.example);
};
}
};
});
When you use a template, it replaces the content of the element the directive is applied to (unless you use replace: true, in which case it replaces the entire element), and the contents of the template are evaluated against the directive scope.
You could do what you are trying to do using the transclude parameter passed to compile (see the docs), but this has been deprecated so I wouldn't recommend going down that road.
Here's a Plunk where you can play with some variations.

Getting MathJax to update after changes to AngularJS model

I am trying to use AngularJS two-way binding text which includes Latex style equations. I would like to call MathJax to format the equations, but I'm not sure of the best way to ensure that MathJax is called after AngularJS finishes changing the model. I think I need a callback. Here is my JavaScript:
var myApp = angular.module('myApp',[]);
function MyCtrl($scope) {
$scope.Update = function() {
$scope.Expression = 'Evaluate: \\( \\frac{9}{4} \\div \\frac{1}{6} \\)';
MathJax.Hub.Queue(["Typeset", MathJax.Hub]);
}
$scope.Expression = 'Evaluate: \\( \\frac{5}{4} \\div \\frac{1}{6} \\)';
}
And here is my HTML:
<div ng-controller="MyCtrl">
<button ng-click="Update()">Update</button>
{{Expression}}
</div>
Fiddle is here: http://jsfiddle.net/LukasHalim/UVjTD/1/. You'll notice that on the fiddle the original expression isn't removed even after you click the update button twice - seems like a bug or conflict.
Having wasted many days (and maybe weeks) fighting MathJax, I'm all too familiar with its various quirks with updating math expressions on the fly. I'm brand new to Angular but this gave me a good chance to dive in and I ended up with a solution which solves my problems -- hopefully it'll solve yours as well.
Live demo: jsfiddle
Instead of using the plain interpolation that Angular provides, I created a new directive based on ng-bind called mathjax-bind.
If expression is a variable containing math code, then instead of \( {{expression}} \) you can write:
<span mathjax-bind="expression"></span>
and everything will be typeset and updated at the appropriate times.
The supporting code for the directive follows:
myApp.directive("mathjaxBind", function() {
return {
restrict: "A",
controller: ["$scope", "$element", "$attrs",
function($scope, $element, $attrs) {
$scope.$watch($attrs.mathjaxBind, function(texExpression) {
var texScript = angular.element("<script type='math/tex'>")
.html(texExpression ? texExpression : "");
$element.html("");
$element.append(texScript);
MathJax.Hub.Queue(["Reprocess", MathJax.Hub, $element[0]]);
});
}]
};
});
Simplest, fastest and most stable solution:
$rootScope.$watch(function(){
MathJax.Hub.Queue(["Typeset",MathJax.Hub]);
return true;
});
Advantages:
Easy to setup, just copy this code.
Everything on your page is typeset.
It renders much faster than the other solutions. This is because it can render the page in one go. Other answers here wait for one item to finish, until they typeset the next one. That makes rendering veeeery slow if there are for example multiple mathjax-bind directives (as another answer suggests). This point is the reason I was looking for a different answer.
You can still easily exclude elements using the option “ignoreClass” in your mathjax settings.
Benchmarking:
100 mathjax-bind directives took 63 seconds, while with this method it took 1.5 second to render the page. I know that this function will be executed a lot since it's called on every digest cycle, however, it doesn't noticeably slow down the page.
I created a simple fiddle expanding on Ben Alpert's answer. Here's the fiddle and plunk.
Specifically If a text has only a part of it to be converted by Mathjax, you can use this.
For inline mathjax you must surround the text by $, and for block display you must surround the block by $$. (You can use any format you like if you create the corresponding regex)
app.js
MathJax.Hub.Config({
skipStartupTypeset: true,
messageStyle: "none",
"HTML-CSS": {
showMathMenu: false
}
});
MathJax.Hub.Configured();
var myApp = angular.module("myApp", []);
myApp.directive("mathjaxBind", function() {
return {
restrict: "A",
scope:{
text: "#mathjaxBind"
},
controller: ["$scope", "$element", "$attrs", function($scope, $element, $attrs) {
$scope.$watch('text', function(value) {
var $script = angular.element("<script type='math/tex'>")
.html(value == undefined ? "" : value);
$element.html("");
$element.append($script);
MathJax.Hub.Queue(["Reprocess", MathJax.Hub, $element[0]]);
});
}]
};
});
myApp.directive('dynamic', function ($compile) {
return {
restrict: 'A',
replace: true,
link: function (scope, ele, attrs) {
scope.$watch(attrs.dynamic, function(html) {
html = html.replace(/\$\$([^$]+)\$\$/g, "<span class=\"blue\" mathjax-bind=\"$1\"></span>");
html = html.replace(/\$([^$]+)\$/g, "<span class=\"red\" mathjax-bind=\"$1\"></span>");
ele.html(html);
$compile(ele.contents())(scope);
});
}
};
});
function MyCtrl($scope, $element) {
$scope.html = "A coin of is $ \\frac{5}{4} $ thrown $$\\frac{1}{6}$$ dfv";
}
index.html
<!DOCTYPE html>
<html ng-app="myApp">
<head>
<meta charset="utf-8" />
<title>AngularJS Plunker</title>
<script>document.write('<base href="' + document.location + '" />');</script>
<script src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML&delayStartupUntil=configured&dummy=.js"></script>
<link rel="stylesheet" href="style.css" />
<script data-require="angular.js#1.2.x" src="http://code.angularjs.org/1.2.7/angular.js" data-semver="1.2.7"></script>
<script src="app.js"></script>
</head>
<body>
<div ng-controller="MyCtrl">
<input type="text" ng-model="html"/><br/>
<div dynamic="html"></div>
</div>
</body>
style.css
input[type="text"] {
width: 800px;
}
.red{
color:red;
display:inline-block;
}
.blue{
color:blue;
display:block;
}
Take a look at http://jsfiddle.net/pz5Jc/
In your template:
{{Label}} <span id="mathElement">{{Expression}}</span>
In your controller:
$scope.Update = function() {
$scope.Expression = '\\frac{9}{4} \\div \\frac{1}{6}';
$scope.Label = 'Updated Expression:'
var math = MathJax.Hub.getAllJax("mathElement")[0];
math.Text('\\frac{4}{4} \\div \\frac{2}{6}');
}
Couple of points:
I'm not too familiar with mathjax, but:
Splitting the label out from the expression allows you to work with the expression directly.
You need to manually pick up a DOM element to force a refresh of the expression. This isn't a very 'angular' way to do things unfortunately - but when mathjax parses the expression (and inserts it's own DOM elements), it pushes those elements outside the angular bindings.
Fix here is to specifically select the correct mathjax element and call a text change function to update the expression.
Here's a directive that lets you use double curly markup inside the expression (and doesn't require setting an expression variable on the scope). It's based on this blog post, except I only support MathJax, and I save the compiled DOM, so that it updates on changes to scope variables.
As Alex Osborn said, it's best to separate non-math from math.
Usage:
<p>This is inline math: <latex>x^{ {{power}} }</latex>,
and this is display math: <div latex> y^{ {{power}} } .</div></p>
In a snippet:
angular.module('app', [])
.controller('ctrl', function($scope) {
$scope.power = "\\sin(x^2)";
})
.directive('latex', function() {
return {
restrict: 'AE',
link: function(scope, element) {
var newDom = element.clone();
element.replaceWith(newDom);
var pre = "\\(",
post = "\\)";
if (element[0].tagName === 'DIV') {
pre = "\\[";
post = "\\]";
}
scope.$watch(function() {
return element.html();
}, function() {
console.log(element);
newDom.html(pre + element.html() + post);
MathJax.Hub.Typeset(newDom[0]);
});
}
}
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
<div ng-app="app" ng-controller="ctrl">
<p>Power:
<input ng-model="power" />
</p>
<p>This is the inline latex,
<latex>x^{ {{power}} }</latex>, followed by some display mode latex
<div latex>y^{ {{power}} } = {{power}}.</div>And that's it!
</p>
</div>
A simple solution is to use $timeout to put MathJax.Hub.Queue(["Typeset", MathJax.Hub]) in the browser event queue (see Run a directive after the DOM has finished rendering).
Something like this:
var app = angular.module('myApp', []);
app.controller('myController', function ($scope, $timeout) {
controller = this;
$scope.Update = function () {
$scope.value = " \\( \\frac{5}{4} \\div \\frac{1}{6} \\)";
$timeout(controller.updateMathJax, 0);
}
this.updateMathJax = function () {
MathJax.Hub.Queue(["Typeset", MathJax.Hub]);
}
});
You can try with my modifications http://jsfiddle.net/bmma8/4/
modify input or click on button will update your expression.
js:
MathJax.Hub.Config({
extensions: ["tex2jax.js"],
jax: ["input/TeX","output/HTML-CSS"],
tex2jax: {inlineMath: [["$","$"],["\\(","\\)"]]}
});
var myApp = angular.module('myApp',[]);
function MyCtrl($scope, $log) {
var QUEUE = MathJax.Hub.queue; // shorthand for the queue
$scope.Update = function() {
QUEUE.Push(["Text",MathJax.Hub.getAllJax("MathOutput")[0],"\\displaystyle{"+ $scope.Expression+"}"]);
//$scope.Expression = 'Updated Expression: \\( \\frac{9}{4} \\div \\frac{1}{6} \\)';
//MathJax.Hub.Queue(["Typeset", MathJax.Hub]);
}
$scope.Expression = 'Original Expression: \\( \\frac{5}{4} \\div \\fra
and html:
<div ng-controller="MyCtrl">
<button ng-click="Update()">Update</button>
<input ng-model="Expression" ng-change="Update()">
<div id="MathOutput">
You typed: ${}$
</div>
</div>
Alexandre
I actually thought of another solution. When you render some angular and math you do this:
ANGULAR CONTROLLER
$scope x = 5;
HTML
<h3> {{ '$ Multiplication = '+ x + ' * 2 =' + (x*2) + '$'}} </h3>
Formated Math Jax result
Multiplication = 5 * 2 = 10
The key is to include the dollar signs inside the brackets as text. When Angular renders them, the dollar signs will appear as plain text, but when the Math Jax format comes into action it will recognize the dollar signs and do the magic.
I Build a directive for this....
FIDDLE: http://jsfiddle.net/8YkUS/1/
HTML
p data-math-exp data-value="math">
JAVASCRIPT
appFlipped.directive("mathExp", function () {
return {
scope: {
value: "="
},
link: function (scope, el) {
var domEl = el[0];
scope.$watch("value", function (newValue) {
//nothing to do here
if (newValue == null || window.MathJax == null)return;
//update the dom with the new value and pass the hub for styling the equation
domEl.innerHTML = '`' + newValue + '`';
MathJax.Hub.Queue(["Typeset", MathJax.Hub, domEl]);
});
}
}
});
I fiddled a bit more on Roney's solution. The display math should be displayed in display mode; with
<script type="math/tex; mode=display">
I added an attribute to the generated span to indicate that.
Fiddle is here http://jsfiddle.net/repa/aheujhfq/8/

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