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authorChristian Schneider2006-10-26 13:35:12 +0000
committerChristian Schneider2006-10-26 13:35:12 +0000
commita5a19fd672bc0b8113d620669b557f17dccd343a (patch)
tree876ba4fec8362ac2e9374f61b9b7f67fcd2b8e59 /itjs/loader.js
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Moved itools to live branch
Diffstat (limited to 'itjs/loader.js')
-rw-r--r--itjs/loader.js207
1 files changed, 207 insertions, 0 deletions
diff --git a/itjs/loader.js b/itjs/loader.js
new file mode 100644
index 0000000..19f5f9c
--- /dev/null
+++ b/itjs/loader.js
@@ -0,0 +1,207 @@
+/**
+ * Create loader to request data from server
+ *
+ * @param handler Object providing clear()/render() function when data arrives
+ */
+function it_loader(handler)
+{
+ /* Clear cache etc. if completely new data */
+ this.loader = null;
+ this.handler = handler;
+ this.name = "it_loader";
+ this.callid = 0;
+ this.clear();
+}
+
+/* Methods */
+it_loader.prototype =
+{
+
+/* Clear cache and initialize handler */
+clear: function()
+{
+ /* Clear cache etc. if completely new data */
+ this.entry = new Array();
+ this.start = this.end = 0;
+ this.attr = { num: 0, loadtime: 0 };
+
+ if (this.handler.clear)
+ this.handler.clear();
+},
+
+load: function(baseurl, pos, num, query_volatile, retry)
+{
+ /* Convert to int */
+ pos -= 0;
+ num -= 0;
+
+ if (isNaN(retry))
+ retry = 0;
+
+ if (baseurl != this.baseurl)
+ {
+ this.clear();
+ this.baseurl = baseurl;
+ this.start = this.end = pos;
+ }
+
+ this.pos = pos;
+ this.num = num;
+ this.query_volatile = query_volatile;
+
+ if (this.loader)
+ this.stop();
+
+ while ((num > 0) && this.entry[pos])
+ {
+ pos++;
+ num--;
+ }
+
+ if (this.attr.eof)
+ num = Math.min(num, this.end - pos);
+
+ if (num > 0)
+ {
+ if (retry)
+ baseurl += "&retry=" + retry;
+
+ try
+ {
+ this.loader = new XMLHttpRequest();
+ }
+ catch (e)
+ {
+ var classnames = [ 'MSXML2.XMLHTTP', 'Microsoft.XMLHTTP' ];
+
+ for (var i in classnames)
+ {
+ try
+ {
+ this.loader = new ActiveXObject(classnames[i]);
+ break;
+ }
+ catch (e) {}
+ }
+ }
+
+ try
+ {
+ this.loader.open("GET", baseurl + "&pos=" + pos + "&num=" + num + (query_volatile ? query_volatile : ""));
+ var me = this;
+ this.loader.onreadystatechange = function() { me.readyStateChanged(); }
+ var workingxmlhttp = this.loader.onreadystatechange;
+
+ if (!workingxmlhttp) /* Old Konqueror */
+ this.loader = null;
+ }
+ catch (e) { }
+
+ if (this.loader)
+ {
+ this.starttime = new Date().getTime();
+ this.retry = retry;
+ this.loader.send(null);
+ }
+ else
+ {
+
+ if (!this.iframe)
+ {
+ this.iframe = document.createElement("iframe");
+ this.iframe.frameBorder = 0;
+ this.iframe.style.width = this.iframe.style.height = 1;
+ document.body.appendChild(this.iframe);
+ }
+
+ this.loader = { starttime: new Date().getTime(), retry: retry };
+ var loaderinstance = this.name;
+ window[loaderinstance] = this;
+ this.iframe.src = baseurl + "&pos=" + pos + "&num=" + num + '&itjs_call=parent.' + loaderinstance + '.dataReady&itjs_callid=' + ++this.callid;
+ }
+ }
+ else
+ this.handler.render(this);
+},
+
+readyStateChanged: function()
+{
+ var loader = this.loader; // Avoid race conditions
+
+ if (loader && (loader.readyState == 4))
+ {
+ var data = null;
+
+ try
+ {
+ if (loader.responseText != "")
+ data = eval("("+ loader.responseText + ")");
+ }
+ catch (e)
+ {
+ var retry = this.retry + 1;
+
+ if (retry < 10)
+ it_timer({ object: this, method: "retryload", timeout: Math.pow(5, Math.min(retry, 5)), baseurl: this.baseurl, pos: this.pos, num: this.num, query_volatile: this.query_volatile, retry: retry });
+ else
+ ED(e, loader.responseText);
+ }
+
+ if (data)
+ this.dataReady(data, this.callid);
+ }
+},
+
+retryload: function(p)
+{
+ this.load(p.baseurl, p.pos, p.num, p.query_volatile, p.retry);
+},
+
+dataReady: function(data, callid)
+{
+ var fixkonqueror33gcbug = this.loader;
+ var loadtime = new Date().getTime() - this.starttime;
+
+ this.loader = null;
+
+ if ((typeof data == "object") && (this.callid == callid))
+ {
+ this.attr = { loadtime: loadtime };
+
+ for (var key in data)
+ {
+ var value = data[key];
+ var id = key - 0;
+
+ if (!isNaN(id))
+ {
+ this.start = Math.min(this.start, id);
+ this.end = Math.max(this.end, id + 1);
+ this.entry[id] = data[key];
+ }
+ else
+ this.attr[key] = data[key];
+ }
+
+ if (this.attr.eof)
+ this.attr.num = this.end; /* Fix bogus # of result value */
+
+ this.handler.render(this);
+
+ if (!this.attr.eof && (this.end < this.pos + this.num))
+ this.load(this.baseurl, this.end, this.pos + this.num - this.end);
+ }
+},
+
+stop: function()
+{
+ try
+ {
+ this.loader.abort();
+ }
+ catch (e) { }
+
+ this.loader = null;
+}/* NO COMMA */
+
+}