Angularjs directive to replace text

Question

How would I create a directive in angularjs that for example takes this element:

Example text http://example.com

And

Answer 1

I wanted a pause button that swaps text. here is how I did it:

in CSS:

.playpause.paused .pause, .playpause .play { display:none; }
.playpause.paused .play { display:inline; }

in template:

<button class="playpause" ng-class="{paused:paused}" ng-click="paused = !paused">
  <span class="play">play</span><span class="pause">pause</span>
</button>

Answer 2

Inspired by @Neal I made this "no sanitize" filter from the newer Angular 1.5.8. It also recognizes addresses without ftp|http(s) but starting with www. This means that both https://google.com and www.google.com will be linkyfied.

angular.module('filter.parselinks',[])

.filter('parseLinks', ParseLinks);

function ParseLinks() {
  var LINKY_URL_REGEXP =
        /((ftp|https?):\/\/|(www\.)|(mailto:)?[A-Za-z0-9._%+-]+@)\S*[^\s.;,(){}<>"\u201d\u2019]/i,
      MAILTO_REGEXP = /^mailto:/i;

  var isDefined = angular.isDefined;
  var isFunction = angular.isFunction;
  var isObject = angular.isObject;
  var isString = angular.isString;

  return function(text, target, attributes) {
    if (text == null || text === '') return text;
    if (typeof text !== 'string') return text;

    var attributesFn =
      isFunction(attributes) ? attributes :
      isObject(attributes) ? function getAttributesObject() {return attributes;} :
      function getEmptyAttributesObject() {return {};};

    var match;
    var raw = text;
    var html = [];
    var url;
    var i;
    while ((match = raw.match(LINKY_URL_REGEXP))) {
      // We can not end in these as they are sometimes found at the end of the sentence
      url = match[0];
      // if we did not match ftp/http/www/mailto then assume mailto
      if (!match[2] && !match[4]) {
        url = (match[3] ? 'http://' : 'mailto:') + url;
      }
      i = match.index;
      addText(raw.substr(0, i));
      addLink(url, match[0].replace(MAILTO_REGEXP, ''));
      raw = raw.substring(i + match[0].length);
    }
    addText(raw);
    return html.join('');

    function addText(text) {
      if (!text) {
        return;
      }
      html.push(text);
    }

    function addLink(url, text) {
      var key, linkAttributes = attributesFn(url);
      html.push('<a ');

      for (key in linkAttributes) {
        html.push(key + '="' + linkAttributes[key] + '" ');
      }

      if (isDefined(target) && !('target' in linkAttributes)) {
        html.push('target="',
                  target,
                  '" ');
      }
      html.push('href="',
                url.replace(/"/g, '&quot;'),
                '">');
      addText(text);
      html.push('</a>');
    }
  };
}

Answer 3

I would analyze the text in the link function on the directive:

directive("myDirective", function(){

  return {
        restrict: "A",
        link: function(scope, element, attrs){
          // use the 'element' to manipulate it's contents...
        }
      }
  });

Answer 4

Two ways of doing it:

Directive

app.directive('parseUrl', function () {
    var urlPattern = /(http|ftp|https):\/\/[\w-]+(\.[\w-]+)+([\w.,@?^=%&:\/~+#-]*[\w@?^=%&\/~+#-])?/gi;
    return {
        restrict: 'A',
        require: 'ngModel',
        replace: true,
        scope: {
            props: '=parseUrl',
            ngModel: '=ngModel'
        },
        link: function compile(scope, element, attrs, controller) {
            scope.$watch('ngModel', function (value) {
                var html = value.replace(urlPattern, '<a target="' + scope.props.target + '" href="$&">$&</a>') + " | " + scope.props.otherProp;
                element.html(html);
            });
        }
    };
});

HTML:

<p parse-url="props" ng-model="text"></p>

Filter

app.filter('parseUrlFilter', function () {
    var urlPattern = /(http|ftp|https):\/\/[\w-]+(\.[\w-]+)+([\w.,@?^=%&:\/~+#-]*[\w@?^=%&\/~+#-])?/gi;
    return function (text, target, otherProp) {
        return text.replace(urlPattern, '<a target="' + target + '" href="$&">$&</a>') + " | " + otherProp;
    };
});

HTML:

<p ng-bind-html-unsafe="text | parseUrlFilter:'_blank':'otherProperty'"></p>

Note: The 'otherProperty' is just for example, in case you want to pass more properties into the filter.

jsFiddle

Update: Improved replacing algorithm.

Answer 5

To answer the first half of this question, without the additional property requirement, one can use Angular's linky filter: https://docs.angularjs.org/api/ngSanitize/filter/linky

Answer 6

The top voted answer does not work if there are multiple links. Linky already does 90% of the work for us, the only problem is that it sanitizes the html thus removing html/newlines. My solution was to just edit the linky filter (below is Angular 1.2.19) to not sanitize the input.

app.filter('linkyUnsanitized', ['$sanitize', function($sanitize) {
  var LINKY_URL_REGEXP =
        /((ftp|https?):\/\/|(mailto:)?[A-Za-z0-9._%+-]+@)\S*[^\s.;,(){}<>]/,
      MAILTO_REGEXP = /^mailto:/;

  return function(text, target) {
    if (!text) return text;
    var match;
    var raw = text;
    var html = [];
    var url;
    var i;
    while ((match = raw.match(LINKY_URL_REGEXP))) {
      // We can not end in these as they are sometimes found at the end of the sentence
      url = match[0];
      // if we did not match ftp/http/mailto then assume mailto
      if (match[2] == match[3]) url = 'mailto:' + url;
      i = match.index;
      addText(raw.substr(0, i));
      addLink(url, match[0].replace(MAILTO_REGEXP, ''));
      raw = raw.substring(i + match[0].length);
    }
    addText(raw);
    return html.join('');

    function addText(text) {
      if (!text) {
        return;
      }
      html.push(text);
    }

    function addLink(url, text) {
      html.push('<a ');
      if (angular.isDefined(target)) {
        html.push('target="');
        html.push(target);
        html.push('" ');
      }
      html.push('href="');
      html.push(url);
      html.push('">');
      addText(text);
      html.push('</a>');
    }
  };
}]);