JSOM Dynamicly Get Two Announcements From All Lists In All Webs

Need help with the chaining. The functions work. But async calls make it hard for me to get everything. Help me think right! My thought: Get All Webs recursively (function works)

Solution 1:

Given the requirements to retrieve list items from Announcements lists located across site collection, below is demonstrated the modified example that contains some improvements such as:

• the number of requests to the server is reduced
• fixed the issue in getAllWebs function that prevents to return any results if site contains only a root web

Example

function getAllWebs(propertiesToRetrieve,success, error) {
    var ctx = SP.ClientContext.get_current();
    var web = ctx.get_site().get_rootWeb();
    var result = [];
    var level = 0;
    ctx.load(web, propertiesToRetrieve);
    result.push(web);
    var getAllWebsInner = function (web, result, success, error) {
        level++;
        var ctx = web.get_context();
        var webs = web.get_webs();
        var includeExpr = 'Include(Webs,' + propertiesToRetrieve.join(',') + ')';
        ctx.load(webs, includeExpr);
        ctx.executeQueryAsync(
          function () {
              for (var i = 0; i < webs.get_count() ; i++) {
                  var web = webs.getItemAtIndex(i);
                  result.push(web);
                  if (web.get_webs().get_count() > 0) {
                      getAllWebsInner(web, result, success, error);
                  }
              }
              level--;
              if (level == 0 && success)
                  success(result);
          },
          error);
    };
    getAllWebsInner(web, result, success, error);
}



function loadListItems(lists,query,success,error,results){
    var results = results || [];
    var curList = lists[0];
    var ctx = curList.get_context();
    var listItems = curList.getItems(query);
    ctx.load(listItems);
    ctx.executeQueryAsync(function () {
        results.push.apply(results, listItems.get_data());
        lists.shift();
        if(lists.length > 0) {
            loadListItems(lists,query,success,error,results);
        }
        if(lists.length == 0)
           success(results);
    }, error);
}


function dynamicSort(property) {
    var sortOrder = 1;
    if (property[0] === "-") {
        sortOrder = -1;
        property = property.substr(1);
    }
    return function (a, b) {
        var result = (a[property] < b[property]) ? -1 : (a[property] > b[property]) ? 1 : 0;
        return result * sortOrder;
    }
}


var propertiesToRetrieve = ['Lists.Include(BaseTemplate)','ServerRelativeUrl'];
getAllWebs(propertiesToRetrieve,
function(allwebs){

    //1. get filtered lists
    var allAnnouncementLists = [];
    allwebs.forEach(function(w){
        var announcementLists = w.get_lists().get_data().filter(function(l){
            if(l.get_baseTemplate() == SP.ListTemplateType.announcements)
               return l;
        });
        allAnnouncementLists.push.apply(allAnnouncementLists, announcementLists);
    });



    //2.Load list items from lists
    var query = new SP.CamlQuery();  //<-set your custom query here
    loadListItems(allAnnouncementLists,query,
        function(allListItems){            
            //3.Sort and print results
           var sortedItems = allListItems.sort(dynamicSort("get_created()"));
           sortedItems.forEach(function(item){
              console.log(item.get_item('Title')); 
           });
        },logError);
},
logError);



function logError(sender,args){
    console.log(args.get_message());
}