HTMLSimpleDOM

build

strict nullable bool

if errors are detected, halt and return null

markCache nullable Object

a cache that can be used in ID generation (is passed to `getID`)

Returns: SimpleNode

root of tree or null if parsing failed

Show code

    Builder.prototype.build = function (strict, markCache) {
        var self = this;
        var token, lastClosedTag, lastTextNode;
        var stack = this.stack;
        var attributeName = null;
        var nodeMap = {};

        markCache = markCache || {};

        // Start timers for building full and partial DOMs.
        // Appropriate timer is used, and the other is discarded.
        var timerBuildFull = "HTMLInstr. Build DOM Full";
        var timerBuildPart = "HTMLInstr. Build DOM Partial";
        PerfUtils.markStart([timerBuildFull, timerBuildPart]);

        function closeTag(endIndex, endPos) {
            lastClosedTag = stack[stack.length - 1];
            stack.pop();
            lastClosedTag.update();

            lastClosedTag.end = self.startOffset + endIndex;
            lastClosedTag.endPos = _addPos(self.startOffsetPos, endPos);
        }

        while ((token = this.t.nextToken()) !== null) {
            // lastTextNode is used to glue text nodes together
            // If the last node we saw was text but this one is not, then we're done gluing.
            // If this node is a comment, we might still encounter more text.
            if (token.type !== "text" && token.type !== "comment" && lastTextNode) {
                lastTextNode = null;
            }

            if (token.type === "error") {
                PerfUtils.finalizeMeasurement(timerBuildFull);  // discard
                PerfUtils.addMeasurement(timerBuildPart);       // use
                this._logError(token);
                return null;
            } else if (token.type === "opentagname") {
                var newTagName = token.contents.toLowerCase(),
                    newTag;

                if (openImpliesClose.hasOwnProperty(newTagName)) {
                    var closable = openImpliesClose[newTagName];
                    while (stack.length > 0 && closable.hasOwnProperty(stack[stack.length - 1].tag)) {
                        // Close the previous tag at the start of this tag.
                        // Adjust backwards for the < before the tag name.
                        closeTag(token.start - 1, _offsetPos(token.startPos, -1));
                    }
                }

                newTag = new SimpleNode({
                    tag: token.contents.toLowerCase(),
                    children: [],
                    attributes: {},
                    parent: (stack.length ? stack[stack.length - 1] : null),
                    start: this.startOffset + token.start - 1,
                    startPos: _addPos(this.startOffsetPos, _offsetPos(token.startPos, -1)) // ok because we know the previous char was a "<"
                });
                newTag.tagID = this.getID(newTag, markCache);

                // During undo in particular, it's possible that tag IDs may be reused and
                // the marks in the document may be misleading. If a tag ID has been reused,
                // we apply a new tag ID to ensure that our edits come out correctly.
                if (nodeMap[newTag.tagID]) {
                    newTag.tagID = this.getNewID();
                }

                nodeMap[newTag.tagID] = newTag;
                if (newTag.parent) {
                    newTag.parent.children.push(newTag);
                }
                this.currentTag = newTag;

                if (voidElements.hasOwnProperty(newTag.tag)) {
                    // This is a self-closing element.
                    newTag.update();
                } else {
                    stack.push(newTag);
                }
            } else if (token.type === "opentagend" || token.type === "selfclosingtag") {
                // TODO: disallow <p/>?
                if (this.currentTag) {
                    if (token.type === "selfclosingtag" && stack.length && stack[stack.length - 1] === this.currentTag) {
                        // This must have been a self-closing tag that we didn't identify as a void element
                        // (e.g. an SVG tag). Pop it off the stack as if we had encountered its close tag.
                        closeTag(token.end, token.endPos);
                    } else {
                        // We're ending an open tag. Record the end of the open tag as the end of the
                        // range. (If we later find a close tag for this tag, the end will get overwritten
                        // with the end of the close tag. In the case of a self-closing tag, we should never
                        // encounter that.)
                        // Note that we don't need to update the signature here because the signature only
                        // relies on the tag name and ID, and isn't affected by the tag's attributes, so
                        // the signature we calculated when creating the tag is still the same. If we later
                        // find a close tag for this tag, we'll update the signature to account for its
                        // children at that point (in the next "else" case).
                        this.currentTag.openEnd = this.currentTag.end = this.startOffset + token.end;
                        this.currentTag.endPos = _addPos(this.startOffsetPos, token.endPos);
                        lastClosedTag = this.currentTag;
                        this.currentTag.updateAttributeSignature();
                        this.currentTag = null;
                    }
                }
            } else if (token.type === "closetag") {
                // If this is a self-closing element, ignore the close tag.
                var closeTagName = token.contents.toLowerCase();
                if (!voidElements.hasOwnProperty(closeTagName)) {
                    // Find the topmost item on the stack that matches. If we can't find one, assume
                    // this is just a dangling closing tag and ignore it.
                    var i;
                    for (i = stack.length - 1; i >= 0; i--) {
                        if (stack[i].tag === closeTagName) {
                            break;
                        }
                    }
                    if (strict && i !== stack.length - 1) {
                        // If we're in strict mode, treat unbalanced tags as invalid.
                        PerfUtils.finalizeMeasurement(timerBuildFull);
                        PerfUtils.addMeasurement(timerBuildPart);
                        this._logError(token);
                        return null;
                    }
                    if (i >= 0) {
                        do {
                            // For all tags we're implicitly closing (before we hit the matching tag), we want the
                            // implied end to be the beginning of the close tag (which is two characters, "</", before
                            // the start of the tagname). For the actual tag we're explicitly closing, we want the
                            // implied end to be the end of the close tag (which is one character, ">", after the end of
                            // the tagname).
                            if (stack.length === i + 1) {
                                closeTag(token.end + 1, _offsetPos(token.endPos, 1));
                            } else {
                                closeTag(token.start - 2, _offsetPos(token.startPos, -2));
                            }
                        } while (stack.length > i);
                    } else {
                        // If we're in strict mode, treat unmatched close tags as invalid. Otherwise
                        // we just silently ignore them.
                        if (strict) {
                            PerfUtils.finalizeMeasurement(timerBuildFull);
                            PerfUtils.addMeasurement(timerBuildPart);
                            this._logError(token);
                            return null;
                        }
                    }
                }
            } else if (token.type === "attribname") {
                attributeName = token.contents.toLowerCase();
                // Set the value to the empty string in case this is an empty attribute. If it's not,
                // it will get overwritten by the attribvalue later.
                this.currentTag.attributes[attributeName] = "";
            } else if (token.type === "attribvalue" && attributeName !== null) {
                this.currentTag.attributes[attributeName] = token.contents;
                attributeName = null;
            } else if (token.type === "text") {
                if (stack.length) {
                    var parent = stack[stack.length - 1];
                    var newNode;

                    // Check to see if we're continuing a previous text.
                    if (lastTextNode) {
                        newNode = lastTextNode;
                        newNode.content += token.contents;
                    } else {
                        newNode = new SimpleNode({
                            parent: stack[stack.length - 1],
                            content: token.contents
                        });
                        parent.children.push(newNode);
                        newNode.tagID = getTextNodeID(newNode);
                        nodeMap[newNode.tagID] = newNode;
                        lastTextNode = newNode;
                    }

                    newNode.update();
                }
            }
        }

        // If we have any tags hanging open (e.g. html or body), fail the parse if we're in strict mode,
        // otherwise close them at the end of the document.
        if (stack.length) {
            if (strict) {
                PerfUtils.finalizeMeasurement(timerBuildFull);
                PerfUtils.addMeasurement(timerBuildPart);
                this._logError(token);
                return null;
            } else {
                // Manually compute the position of the end of the text (we can't rely on the
                // tokenizer for this since it may not get to the very end)
                // TODO: should probably make the tokenizer get to the end...
                var lines = this.text.split("\n"),
                    lastPos = {line: lines.length - 1, ch: lines[lines.length - 1].length};
                while (stack.length) {
                    closeTag(this.text.length, lastPos);
                }
            }
        }

        var dom = lastClosedTag;
        if (!dom) {
            // This can happen if the document has no nontrivial content, or if the user tries to
            // have something at the root other than the HTML tag. In all such cases, we treat the
            // document as invalid.
            this._logError(token);
            return null;
        }

        dom.nodeMap = nodeMap;
        PerfUtils.addMeasurement(timerBuildFull);       // use
        PerfUtils.finalizeMeasurement(timerBuildPart);  // discard

        return dom;
    };