XRX/Save File Dialog
Motivation[edit | edit source]
You want to allow the user to save form data into a named file in an eXist collection that will not conflict with existing files.
Method[edit | edit source]
When the user selects a Save button we will use switch/case to open up a save dialogue. In this dialogue we will list all of the current files in a collection and allow the user to create a new file with a name that does not conflict with any existing file names. If the user selects a file from the list, we will replace the current file name with that file name.
Using the get-child-resources Function[edit | edit source]
eXist provides a function that lists the files in a collection. You can get a sorted list of all the files in a collection with the following XQuery
xquery version "1.0";
declare namespace xdb="http://exist-db.org/xquery/xmldb";
declare option exist:serialize "method=xml media-type=text/xml indent=yes";
let $collection := request:get-parameter('collection', '/db/test')
return
<files>{
for $child in xdb:get-child-resources($collection)
order by lower-case($child)
return
<file>{$child}</file>
}</files>
When executed, this XQuery will return the files in a collection. For example here is the URL of an XQuery execution with the collection parameter passed as an argument:
list-files-in-collection.xq?collection=/db/rss
<files>
<file>news.rss</file>
<file>test.rss</file>
</files>
We can then use this XML listing to display a list of existing files and allow the user to select a name that is not on this list.
Sample Program[edit | edit source]
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xf="http://www.w3.org/2002/xforms">
<head>
<title>Save File Dialog</title>
<link type="text/css" rel="stylesheet" href="save-panel.css" />
<xf:model>
<!-- This is the data that we want to save to a file on the server. -->
<xf:instance id="my-data" xmlns="">
<data>
<element1>Element 1</element1>
<element2>Element 2</element2>
<element3>Element 3</element3>
<!-- This is the file name that we are going to save the data into. -->
<filename>my-filename.xml</filename>
</data>
</xf:instance>
<!-- Placeholder for the list of files in the target collection. -->
<xf:instance xmlns="" id="list-files-results">
<data/>
</xf:instance>
<!-- This does the save. The server-side script must look for the filename element to do the save
to the correct file. -->
<xf:submission id="save" method="post" action="save.xq" ref="my-data" replace="all" />
<!-- Gets the list of current files in the server-side collection and puts them in the model. -->
<xf:submission id="list-files" method="post" action="list-files.xq" replace="instance" instance="list-files-results" />
</xf:model>
</head>
<body>
<h1>Example of Save File Panel</h1>
<xf:input ref="element1">
<xf:label>Element 1:</xf:label>
</xf:input>
<br/>
<xf:input ref="element2">
<xf:label>Element 2:</xf:label>
</xf:input>
<br/>
<xf:input ref="element3">
<xf:label>Element 3:</xf:label>
</xf:input>
<br/>
<xf:switch>
<xf:case id="default">
<xf:submit submission="save">
<xf:label>Save As...</xf:label>
<xf:toggle case="save-dialog" ev:event="DOMActivate" />
</xf:submit>
</xf:case>
<xf:case id="save-dialog">
<xf:action ev:event="xforms-select">
<xf:send submission="list-files" />
</xf:action>
<!-- This turns all the files into buttons that can be selected to select a specific file. -->
<xf:repeat nodeset="instance('list-files-results')/file" class="list-files" id="list-files-repeat">
<xf:trigger appearance="minimal">
<xf:label>
<xf:output ref="." />
</xf:label>
<xf:action ev:event="DOMActivate">
<!-- Set the filename that we will save to to the value under the selected item. -->
<xf:setvalue
ref="instance('my-data')/filename"
value="instance('list-files-results')/file[index('list-files-repeat')]" />
</xf:action>
</xf:trigger>
</xf:repeat>
<xf:input ref="instance('my-data')/filename">
<xf:label>File Name:</xf:label>
</xf:input>
<br/>
<xf:submit submission="list-files">
<xf:label>Refresh</xf:label>
</xf:submit>
<xf:submit submission="save">
<xf:label>Save</xf:label>
</xf:submit>
</xf:case>
</xf:switch>
</body>
</html>
CSS File[edit | edit source]
@namespace xf url("http://www.w3.org/2002/xforms");
body {font-family: Helvetica, sans-serif;}
.list-files {
font-size: .8em;
color: blue;
background-color: white;
border: 1px solid black;
padding: 5px;
}