1. Copyright © 2016 M/Gateway Developments Ltd
EWD 3 Training Course
Part 23
JavaScript Abstraction of Global Storage:
(d) Traversing a Range of Nodes
Rob Tweed
Director, M/Gateway Developments Ltd
Twitter: @rtweed

2. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting a Loop to Specific Nodes

3. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting a Loop to Specific Nodes
Just get names starting Br
-Briggs
-Bryant
Then fetch the data record for each instance
of the name

4. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting a Loop to Specific Nodes
forEachChild( {prefix: 'Br'} , function{..})
Use the control object argument again
This time limit the loop to a prefix

5. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting a Loop to Specific Nodes
var index = new this.documentStore.DocumentNode('myIndex');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
// limit the traversal to just those child nodes whose names start Br
});

6. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting a Loop to Specific Nodes
var index = new this.documentStore.DocumentNode('myIndex');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
// get each id for each name beginning Br
});
});

7. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting a Loop to Specific Nodes
var index = new this.documentStore.DocumentNode('myIndex');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
console.log(id);
});
});
210
386
23
5321

8. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(id, property) = value

9. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(id, property) = value

10. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(id, property) = value
customer = {
'386': {
firstName: 'John',
lastName: 'Briggs',
address: '123 Acacia Drive',
// …etc
},
// ….etc
}

11. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(id, property) = value
customer = {
'386': {
firstName: 'John',
lastName: 'Briggs',
address: '123 Acacia Drive',
// …etc
},
// ….etc
}

12. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(386,"firstName")="John"
customer(386,"lastName")="Briggs"
customer(386,"address")="123 Acacia Drive"
Customer document represented
in Global Storage

13. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(386,"firstName")="John"
customer(386,"lastName")="Briggs"
customer(386,"address")="123 Acacia Drive"
var index = new this.documentStore.DocumentNode('myIndex');
var customer = new this.documentStore.DocumentNode('customer');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
// use id to point to main data record
var address = customer.$(id).$('address').value;
// … etc
});
});

14. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(386,"firstName")="John"
customer(386,"lastName")="Briggs"
customer(386,"address")="123 Acacia Drive"
var index = new this.documentStore.DocumentNode('myIndex');
var customer = new this.documentStore.DocumentNode('customer');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
// use id to point to main data record
var address = customer.$(id).$('address').value;
// … etc
});
});

15. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(386,"firstName")="John"
customer(386,"lastName")="Briggs"
customer(386,"address")="123 Acacia Drive"
var index = new this.documentStore.DocumentNode('myIndex');
var customer = new this.documentStore.DocumentNode('customer');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
// use id to point to main data record
var address = customer.$(id).$('address').value;
// … etc
});
});

16. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(386,"firstName")="John"
customer(386,"lastName")="Briggs"
customer(386,"address")="123 Acacia Drive"
var index = new this.documentStore.DocumentNode('myIndex');
var customer = new this.documentStore.DocumentNode('customer');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
// use id to point to main data record
var address = customer.$(id).$('address').value;
// … etc
});
});

17. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(386,"firstName")="John"
customer(386,"lastName")="Briggs"
customer(386,"address")="123 Acacia Drive"
var index = new this.documentStore.DocumentNode('myIndex');
var customer = new this.documentStore.DocumentNode('customer');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
// use id to point to main data record
var address = customer.$(id).$('address').value;
// … etc
});
});

18. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(386,"firstName")="John"
customer(386,"lastName")="Briggs"
customer(386,"address")="123 Acacia Drive"
var index = new this.documentStore.DocumentNode('myIndex');
var customer = new this.documentStore.DocumentNode('customer');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
// use id to point to main data record
var address = customer.$(id).$('address').value;
// … etc
});
});

19. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(386,"firstName")="John"
customer(386,"lastName")="Briggs"
customer(386,"address")="123 Acacia Drive"
var index = new this.documentStore.DocumentNode('myIndex');
var customer = new this.documentStore.DocumentNode('customer');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
// use id to point to main data record
var address = customer.$(id).$('address').value;
// … etc
});
});

20. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Index for an Customer Document
customer(386,"firstName")="John"
customer(386,"lastName")="Briggs"
customer(386,"address")="123 Acacia Drive"
var index = new this.documentStore.DocumentNode('myIndex');
var customer = new this.documentStore.DocumentNode('customer');
index.forEachChild({prefix: 'Br}', function(nodeName, childNode) {
childNode.forEachChild(function(id) {
// use id to point to main data record
var address = customer.$(id).$('address').value;
// … etc
});
});

21. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Iterate Prefixes in Reverse Order?

22. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Iterate Prefixes in Reverse Order
var index = new this.documentStore.DocumentNode('myIndex');
var params = {prefix: 'Br', direction: 'reverse'} ;
index.forEachChild(params, function(name, childNode) {
childNode.forEachChild(function(id) {
console.log(id);
});
});

23. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Iterate Prefixes in Reverse Order
var index = new this.documentStore.DocumentNode('myIndex');
var params = {prefix: 'Br', direction: 'reverse'} ;
index.forEachChild(params, function(name, childNode) {
childNode.forEachChild(function(id) {
console.log(id);
});
});
Control object allows prefix to be
combined with reverse

24. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Iterate Prefixes in Reverse Order
var index = new this.documentStore.DocumentNode('myIndex');
var params = {prefix: 'Br', direction: 'reverse'} ;
index.forEachChild(params, function(name, childNode) {
childNode.forEachChild(function(id) {
console.log(id);
});
});
Control object allows prefix to be
combined with reverse
23
5321
210
386

25. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Iterate Prefixes in Reverse Order
var index = new this.documentStore.DocumentNode('myIndex');
var params = {prefix: 'Br', direction: 'reverse'} ;
index.forEachChild(params, function(name, childNode) {
childNode.forEachChild(function(id) {
console.log(id);
});
});
Control object allows prefix to be
combined with reverse
23
5321
210
386
Inner loop is in forward direction!

26. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Iterate Prefixes in Reverse Order
var index = new this.documentStore.DocumentNode('myIndex');
var params = {prefix: 'Br', direction: 'reverse'} ;
index.forEachChild(params, function(name, childNode) {
childNode.forEachChild( {direction: 'reverse'} , function(id) {
console.log(id);
});
});
Use the control object to reverse
the inner loop also

27. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Iterate Prefixes in Reverse Order
var index = new this.documentStore.DocumentNode('myIndex');
var params = {prefix: 'Br', direction: 'reverse'} ;
index.forEachChild(params, function(name, childNode) {
childNode.forEachChild( {direction: 'reverse'} , function(id) {
console.log(id);
});
});
Use the control object to reverse
the inner loop also
5321
23
386
210
Now the output is fully reversed

28. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting the Loop to a Range
From: substring 1
To: substring 2
eg: from Briggs to Davis

29. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting the Loop to a Range
forEachChild({
range: {
from: 'Briggs',
to: 'Davis'
}
}, function{..})

30. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting the Loop to a Range
More likely restriction:
forEachChild({
range: {
from: 'Br',
to: 'Da'
}
}, function{..})
from and to define prefixes within which it returns nodes

31. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting the Loop to a Range
or:
forEachChild({
range: {
from: 'B',
to: 'D'
}
}, function{..})
from and to define prefixes within which it returns nodes

32. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting the Loop to a Range
var index = new this.documentStore.DocumentNode('myIndex');
var params = {
range: {
from: 'Br',
to: 'Da'
}
};
index.forEachChild(params, function(name, childNode) {
childNode.forEachChild(function(id) {
console.log(id);
});
});

33. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Restricting the Loop to a Range
var index = new this.documentStore.DocumentNode('myIndex');
var params = {
range: {
from: 'Br',
to: 'Da'
}
};
index.forEachChild(params, function(name, childNode) {
childNode.forEachChild(function(id) {
console.log(id);
});
}); 210
386
23
5321
641
714
13
8142
9112

34. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Iterating a Range in reverse?

35. Copyright © 2016 M/Gateway Developments Ltd
myIndex("Andrews",103)=""
myIndex("Barton",23)=""
myIndex("Briggs",210)=""
myIndex("Briggs",386)=""
myIndex("Bryant",23)=""
myIndex("Bryant",5321)=""
myIndex("Davies",641)=""
myIndex("Davies",714)=""
myIndex("Davis",13)=""
myIndex("Davis",8142)=""
myIndex("Davis",9112 )=""
myIndex("Douglas",651)=""
myIndex("Ennis",108)=""
myIndex("Ennis",712)=""
Iterating a Range in reverse
var index = new this.documentStore.DocumentNode('myIndex');
var params = {
direction: 'reverse',
range: {
from: 'Br',
to: 'Da'
}
};
index.forEachChild(params, function(name, childNode) {
childNode.forEachChild(function(id) {
console.log(id);
});
});
Control object allows range to be
combined with reverse