How to Open Documents in Office Web Apps in SharePoint apps (Provider Hosted and SharePoint Hosted)

Office web apps are now getting more and more popular with the SharePoint 2013 environment. In native SharePoint environment when you click on a document, it will open in an office online (OWA) based on configuration.

But if you are writing a SharePoint Hosted app or a Provider Hosted app; you might wonder how to open it in office web apps and what is the URL you are going to use.

You can use JSOM and SharePoint REST services to archive this.

First, you need to send a REST request by mentioning file name.

url: AppWebUrlUrl + "/_api/web/GetFileByServerRelativeUrl('server relative file name')",
method: "GET",
contentType: "application/json;odata=verbose",
headers: { "Accept": "application/json; odata=verbose" }

You should carefully give the sever relative file name for this operation, regardless of app type (Provider hosted or a SharePoint Hosted) file name it coming with app web url.

Example:

Absolute File Url

https://oapp-bfb82901075d6b.sharepoint.com/sites/dev/myapp/lists/lcrdocs/file1.doc

Relative File Url

/sites/dev/myapp/lists/lcrdocs/file1.doc

Depending on the App type, either you need to use the RequestExecutor or normal rest approach.

Using RequestExecutor in Provider Hosted Apps

var executor = new SP.RequestExecutor("app web url"); // you need to pass app web url
 
executor.executeAsync({
url: "app web url" + "/_api/web/GetFileByServerRelativeUrl('relative doc url')",
method: "GET",
contentType: "application/json;odata=verbose",
headers: { "Accept": "application/json; odata=verbose" },
success: function (data) {
    var arry = JSON.parse(data.body).d;
    if (arry.LinkingUrl) {
        // can open with office web apps
        var owaurl = "app web url" + 
        "/_layouts/15/WopiFrame.aspx?sourcedoc={" + 
        arry.UniqueId + "}&file=" + 
        encodeURIComponent(arry.Title) + "&action=default";                   
    } else {
        // can not open with office web apps (ex:txt)
    }
},
error: function (data, errorCode, errorMessage) {
// error
}
});

If the LinkingUrl is available, it indicates it can be opened via office web apps. LinkingUrl sometimes returns direct web app url; thus you don’t need to create the Url by amending items but sometimes it returns absolute document Url. The mentioned approach will be suited for both occasions.  

Ajax Request in SharePoint Hosted Apps

$.Ajax({ // Jquery needed
url: "app web url" + "/_api/web/GetFileByServerRelativeUrl('relative doc url')",
method: "GET",
contentType: "application/json;odata=verbose",
headers: { "Accept": "application/json; odata=verbose" },
success: function (data) {
    var arry = JSON.parse(data.body).d;
    if (arry.LinkingUrl) {
        // can open with office web apps
        var owaurl = "app web url" + "/_layouts/15/WopiFrame.aspx?sourcedoc={" + 
	arry.UniqueId + "}&file=" + encodeURIComponent(arry.Title) + "&action=default";                   
    } else {
        // can not open with office web apps (ex:txt)
    }
},
error: function (data, errorCode, errorMessage) {
// error
}
});