#4257 Added functionality to create previews for post links using open graph data from those links. (#4890)

webapp/utils/commons.jsx

@@ -0,0 +1,36 @@
+export function getDistanceBW2Points(point1, point2, xAttr = 'x', yAttr = 'y') {
+    return Math.sqrt(Math.pow(point1[xAttr] - point2[xAttr], 2) + Math.pow(point1[yAttr] - point2[yAttr], 2));
+}
+
+/**
+  * Funtion to return nearest point of given pivot point.
+  * It return two points one nearest and other nearest but having both coorditanes smaller than the given point's coordinates.
+  */
+export function getNearestPoint(pivotPoint, points, xAttr = 'x', yAttr = 'y') {
+    var nearestPoint = {};
+    var nearestPointLte = {};  // Nearest point smaller than or equal to point
+    for (const point of points) {
+        if (typeof nearestPoint[xAttr] === 'undefined' || typeof nearestPoint[yAttr] === 'undefined') {
+            nearestPoint = point;
+        } else if (getDistanceBW2Points(point, pivotPoint, xAttr, yAttr) < getDistanceBW2Points(nearestPoint, pivotPoint, xAttr, yAttr)) {
+        // Check for bestImage
+            nearestPoint = point;
+        }
+
+        if (typeof nearestPointLte[xAttr] === 'undefined' || typeof nearestPointLte[yAttr] === 'undefined') {
+            if (point[xAttr] <= pivotPoint[xAttr] && point[yAttr] <= pivotPoint[yAttr]) {
+                nearestPointLte = point;
+            }
+        } else if (
+        // Check for bestImageLte
+            getDistanceBW2Points(point, pivotPoint, xAttr, yAttr) < getDistanceBW2Points(nearestPointLte, pivotPoint, xAttr, yAttr) &&
+            point[xAttr] <= pivotPoint[xAttr] && point[yAttr] <= pivotPoint[yAttr]
+        ) {
+            nearestPointLte = point;
+        }
+    }
+    return {
+        nearestPoint,
+        nearestPointLte
+    };
+}

webapp/utils/constants.jsx

@@ -146,6 +146,9 @@ export const ActionTypes = keyMirror({
 
     RECEIVED_LOCALE: null,
 
+    UPDATE_OPEN_GRAPH_METADATA: null,
+    RECIVED_OPEN_GRAPH_METADATA: null,
+
     SHOW_SEARCH: null,
 
     USER_TYPING: null,

webapp/utils/utils.jsx

@@ -1324,3 +1324,15 @@ export function handleFormattedTextClick(e) {
         browserHistory.push('/' + TeamStore.getCurrent().name + '/channels/' + channelMentionAttribute.value);
     }
 }
+
+export function isEmptyObject(object) {
+    if (!object) {
+        return true;
+    }
+
+    if (Object.keys(object).length === 0) {
+        return true;
+    }
+
+    return false;
+}