问题
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)
Get all lists from webs and iff announcementlist add to array and pass along
Get two items from all announcmentlists and sort by created.
Add ALL announcement items into one large array (to be able to sort array later.
Heres the code,
function getAllWebs(success, error) {
var ctx = SP.ClientContext.get_current();
var web = ctx.get_site().get_rootWeb();
var result = [];
var level = 0;
result.push(web);
var getAllWebsInner = function (web, result, success, error) {
level++;
var ctx = web.get_context();
var webs = web.get_webs();
ctx.load(webs, 'Include(Title,Webs,ServerRelativeUrl)');
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 error(sender, args) {
console.log(args.get_message());
};
function getAnnouncementLists(web, success, error) {
var dfd = $.Deferred();
var ctx = web.get_context();
var collList = web.get_lists();
var result = []
ctx.load(collList, 'Include(Title, Id, BaseTemplate)');
ctx.executeQueryAsync(function () {
for (var i = 0; i < collList.get_count() ; i++) {
var list = collList.getItemAtIndex(i);
var bTemp = list.get_baseTemplate();
if (bTemp == 104) {
result.push(list);
}
}
//success(result);
dfd.resolve(result);
}, error);
return dfd.promise();
}
function getListItems(list, success, error) {
var dfd = $.Deferred();
var camlQuery = new SP.CamlQuery();
camlQuery.set_viewXml('<View><Query><OrderBy><FieldRef Name="Created" Ascending="False"></FieldRef>'
+ '</OrderBy></Query><ViewFields><FieldRef Name="Title"/><FieldRef Name="Body"/>' +
'<FieldRef Name="Created"/></ViewFields><RowLimit>2</RowLimit></View>');
var listItems = list.getItems(camlQuery);
var result = []
var ctx = list.get_parentWeb().get_context();
ctx.load(listItems);
ctx.executeQueryAsync(function () {
for (var i = 0; i < listItems.get_count() ; i++) {
var item = listItems.getItemAtIndex(i);
result.push(item);
}
dfd.resolve(result);
//success(result);
}, error);
return dfd.promise();
}
function printResults(items) {
var sortedItems = items.sort(dynamicSort("get_created()"));
alert(sortedItems);
}
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;
}
}
$(document).ready(function () {
var items = getAllWebs(
function (allwebs) {
var array = [];
for (var i = 0; i < allwebs.length; i++) {
getAnnouncementLists(allwebs[i]).then(function (announceLists) {
for (var i = 0; i < announceLists.length; i++) {
getListItems(announceLists[i]).then(function (items) {
array.push(items);
});
}
});
}
return array;
}
);
//getAllWebs(
// function (allwebs) {
// for (var i = 0; i < allwebs.length; i++) {
// getAnnouncementLists(allwebs[i],
// function (announceLists) {
// for (var i = 0; i < announceLists.length; i++) {
// getListItems(announceLists[i],
// function (items) {
// printResults(items);
// }, error);
// }
// }, error);
// }
// }, error);
});
回答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
getAllWebsfunction 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());
}
来源：https://stackoverflow.com/questions/34945251/jsom-dynamicly-get-two-announcements-from-all-lists-in-all-webs