github.com/ashishbhate/mattermost-server@v5.11.1+incompatible/api4/openGraph.go (about)

     1  // Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
     2  // See License.txt for license information.
     3  
     4  package api4
     5  
     6  import (
     7  	"net/http"
     8  
     9  	"github.com/mattermost/mattermost-server/model"
    10  	"github.com/mattermost/mattermost-server/utils"
    11  )
    12  
    13  const OPEN_GRAPH_METADATA_CACHE_SIZE = 10000
    14  
    15  var openGraphDataCache = utils.NewLru(OPEN_GRAPH_METADATA_CACHE_SIZE)
    16  
    17  func (api *API) InitOpenGraph() {
    18  	api.BaseRoutes.OpenGraph.Handle("", api.ApiSessionRequired(getOpenGraphMetadata)).Methods("POST")
    19  
    20  	// Dump the image cache if the proxy settings have changed. (need switch URLs to the correct proxy)
    21  	api.ConfigService.AddConfigListener(func(before, after *model.Config) {
    22  		if (before.ImageProxySettings.Enable != after.ImageProxySettings.Enable) ||
    23  			(before.ImageProxySettings.ImageProxyType != after.ImageProxySettings.ImageProxyType) ||
    24  			(before.ImageProxySettings.RemoteImageProxyURL != after.ImageProxySettings.RemoteImageProxyURL) ||
    25  			(before.ImageProxySettings.RemoteImageProxyOptions != after.ImageProxySettings.RemoteImageProxyOptions) {
    26  			openGraphDataCache.Purge()
    27  		}
    28  	})
    29  }
    30  
    31  func getOpenGraphMetadata(c *Context, w http.ResponseWriter, r *http.Request) {
    32  	if !*c.App.Config().ServiceSettings.EnableLinkPreviews {
    33  		c.Err = model.NewAppError("getOpenGraphMetadata", "api.post.link_preview_disabled.app_error", nil, "", http.StatusNotImplemented)
    34  		return
    35  	}
    36  
    37  	props := model.StringInterfaceFromJson(r.Body)
    38  
    39  	url := ""
    40  	ok := false
    41  	if url, ok = props["url"].(string); len(url) == 0 || !ok {
    42  		c.SetInvalidParam("url")
    43  		return
    44  	}
    45  
    46  	ogJSONGeneric, ok := openGraphDataCache.Get(url)
    47  	if ok {
    48  		w.Write(ogJSONGeneric.([]byte))
    49  		return
    50  	}
    51  
    52  	og := c.App.GetOpenGraphMetadata(url)
    53  	ogJSON, err := og.ToJSON()
    54  	openGraphDataCache.AddWithExpiresInSecs(props["url"], ogJSON, 3600) // Cache would expire after 1 hour
    55  	if err != nil {
    56  		w.Write([]byte(`{"url": ""}`))
    57  		return
    58  	}
    59  
    60  	w.Write(ogJSON)
    61  }