I made a basic XML parser supposed to be work in many browsers by using most older functions. What it must do is return an AST (Abstract Syntax Tree) of a XML text in a string.
(it's not cool for HTML because it doesn't recognize names of elements like input, div, etc...)
The following string:
"<!DOCTYPE html><html><Item1 Attribute1="Value"/></html>"
Turns into the following representation array when used in first parameter of call XMLAST:
[
{
type:"List",
name:"!DOCTYPE",
attributes=[
{
name:"html",
value:true
}
]
},
{
type:"List",
name:"html"
},
{
type:"Item",
name:"Item1",
attributes:[
{
name:"Attribute1",
value:"Value"
}
]
},
{
type:"End"
}
]
Both interpreting styles. I removed regular expressions because I care about the support, then just made a loop to remove the unallowed characters from tags or attributes name.
XMLAST=function(text){
var tree,
expect,
textend,
reserve;
tree=[];
expect={};
reserve={};
reserve.path=-1;
reserve.textf="";
reserve.allowed=[
"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z",
"1","2","3","4","5","6","7","8","9","0","-","@","!","#",":",
"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"
];
textend=function(){
if(expect.textend){
if(expect.tag){
if(expect.tagname){
reserve.length=reserve.textf.length;
reserve.tagname="";
for(reserve.i=0;reserve.length>reserve.i;reserve.i++){
reserve.cchar=reserve.textf.charAt(reserve.i);
for(reserve.b=0;67>reserve.b;reserve.b++){
if(reserve.cchar===reserve.allowed[reserve.b]){
reserve.tagname+=reserve.cchar;
break
}
}
}
expect.tagname=false;
if(reserve.curchar===">"){
tree.push({
type:"List",
name:reserve.tagname,
attributes:[]
});
expect.tag=false;
reserve.path++
}else if(reserve.curchar==="/"){
tree.push({
type:"Item",
name:reserve.tagname,
attributes:[]
});
expect.tag=false;
reserve.path++;
reserve.closureindex=text.indexOf(">");
if(reserve.closureindex===-1){
text=""
}else{
text=text.substring(reserve.closureindex)
}
expect.tag=false
}
}else if(expect.closuretagname){
expect.closuretagname=false;
expect.tag=false;
reserve.closureindex=text.indexOf(">");
if(reserve.closureindex!==-1){
text=text.substring(reserve.closureindex);
reserve.parentitem={
type:null
};
reserve.expectend=0;
//Parent item (list) of current item search.
for(reserve.i=reserve.path;reserve.i>-1;reserve.i--){
if(tree[reserve.i].type==="List"){
if(reserve.expectend===0){
reserve.parentitem=tree[reserve.i];
break
}else{
reserve.expectend--
}
}else if(tree[reserve.i].type==="End"){
reserve.expectend++
}
}
reserve.expectend=null;
if(reserve.textf===reserve.parentitem.name){
tree.push({
type:"End"
});
reserve.path++;
expect.tag=false
}
reserve.parentitem=null
}
}else{
/*
** ATTRIBUTE DETECTED **
** NAME FORWARD **
*/
reserve.length=reserve.textf.length;
reserve.attrname="";
for(reserve.i=0;reserve.length>reserve.i;reserve.i++){
reserve.cchar=reserve.textf.charAt(reserve.i);
for(reserve.b=0;67>reserve.b;reserve.b++){
if(reserve.cchar===reserve.allowed[reserve.b]){
reserve.attrname+=reserve.cchar;
break
}
}
}
reserve.attributes.push({
name:reserve.attrname,
value:true
});
if(reserve.curchar==="="){
/*
* CHECK IF ASSIGN VALUE IN QUOTES *
*/
reserve.valueindex=text.charAt(1);
if(reserve.valueindex==='"'||reserve.valueindex==="'"){
reserve.valuestart=text.substring(2);
if((reserve.valuendindex=reserve.valuestart.indexOf(reserve.valueindex))===-1){
text="";
expect.tag=false
}else{
reserve.attributes[reserve.attributes.length-1].value=reserve.valuestart.substring(0,reserve.valuendindex);
text=text.substring(2);
text=text.substring(reserve.valuendindex)
}
}
}else if(reserve.curchar===">"||reserve.curchar==="/"){
tree.push({
type:(reserve.curchar==="/"?"Item":"List"),
name:reserve.tagname,
attributes:reserve.attributes
});
reserve.path++;
expect.tag=false;
if(reserve.curchar==="/"){
reserve.closureindex=text.indexOf(">");
if(reserve.closureindex!==-1){
text=text.substring(reserve.closureindex);
reserve.closureindex=null
}
}
}
}
}else{//Add text as a tree part.
tree.push({
type:"Text",
value:reserve.textf
});
reserve.path++
}
}else if(expect.tag){
if(expect.tagname){
expect.tag=false
}else if(reserve.curchar==="/"){
tree.push({
type:"Item",
name:reserve.tagname,
attributes:reserve.attributes
});
reserve.path++;
expect.tag=false;
text=text.substring(1);
reserve.closureindex=text.indexOf(">");
if(reserve.closureindex!==-1){
text=text.substring(reserve.closureindex)
}
}else if(reserve.curchar===">"){
tree.push({
type:"List",
name:reserve.tagname,
attributes:reserve.attributes
});
expect.tag=false;
reserve.path++
}
}
expect.textend=false
};
for(;;){
reserve.curchar=text.charAt(0);
if(reserve.curchar===""){//End of all. Ignore unfinished rest.
textend();
break
}else if(reserve.curchar==="<"){//Start element.
textend();
expect.closuretagname=false;
if(text.substring(1,4)==="!--"){//comment
/*
<!--* COMMENT *-->
*/
expect.tag=false;
reserve.closureindex=text.indexOf("-->");
tree.push({
type:"Comment",
value:(
reserve.closureindex===-1?//Has closure?
text.substring(4,text.length)//Takes to the end.
://Has closure!
text.substring(4,reserve.closureindex)//Takes to the index of -->.
)
});
reserve.path++;
if(reserve.closureindex!==-1){//Is not it infinite?
text=text.substring(reserve.closureindex+2)
}else{
break//Stop because comment is infinite.
}
}else{
/*
<* TAG START *...
*/
expect.tag=true;
expect.tagname=true;
//Expect for item end and name.
reserve.attributes=[];//Reset attributes.
reserve.tagname="";//Reset tag name.
}
}else if(expect.tag&&(reserve.curchar==="/"||reserve.curchar===">"||reserve.curchar==="="||reserve.curchar===" "||reserve.curchar===" ")){
if(reserve.curchar==="/"){
if(expect.tagname&&!expect.textend){
expect.closuretagname=true;
expect.tagname=false;
expect.textend=false
}else if(expect.tag){//closure <.../*>
textend()
}
}else if(reserve.curchar===">"||reserve.curchar==="="||reserve.curchar===" "||reserve.curchar===" "){
textend()
}
}else{
if(expect.textend){
reserve.textf+=reserve.curchar
}else{
reserve.textf=reserve.curchar;
expect.textend=true
}
}
text=text.substring(1)
};
expect=null;
textend=null;
text=null;
reserve=null;
return tree
}
What can be improved?
